Mercurial > jdk8-mips64-public > corba / file revision

 /*

  * Copyright (c) 1998, 2014, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  */

 /*

  * Licensed Materials - Property of IBM

  * RMI-IIOP v1.0

  * Copyright IBM Corp. 1998 2012  All Rights Reserved

  *

  */

 package com.sun.corba.se.impl.io;

 import java.security.MessageDigest;

 import java.security.NoSuchAlgorithmException;

 import java.security.DigestOutputStream;

 import java.security.AccessController;

 import java.security.PrivilegedExceptionAction;

 import java.security.PrivilegedActionException;

 import java.security.PrivilegedAction;

 import java.lang.reflect.Modifier;

 import java.lang.reflect.Array;

 import java.lang.reflect.Field;

 import java.lang.reflect.Member;

 import java.lang.reflect.Method;

 import java.lang.reflect.Constructor;

 import java.lang.reflect.Proxy;

 import java.lang.reflect.InvocationTargetException;

 import java.io.IOException;

 import java.io.DataOutputStream;

 import java.io.ByteArrayOutputStream;

 import java.io.InvalidClassException;

 import java.io.Externalizable;

 import java.io.Serializable;

 import java.util.Arrays;

 import java.util.Comparator;

 import com.sun.corba.se.impl.util.RepositoryId;

 import org.omg.CORBA.ValueMember;

 import sun.corba.Bridge;

 /**

  * A ObjectStreamClass describes a class that can be serialized to a stream

  * or a class that was serialized to a stream.  It contains the name

  * and the serialVersionUID of the class.

  * <br>

  * The ObjectStreamClass for a specific class loaded in this Java VM can

  * be found using the lookup method.

  *

  * @author  Roger Riggs

  * @since   JDK1.1

  */

 public class ObjectStreamClass implements java.io.Serializable {

     private static final boolean DEBUG_SVUID = false ;

     public static final long kDefaultUID = -1;

     private static Object noArgsList[] = {};

     private static Class<?> noTypesList[] = {};

     /** true if represents enum type */

     private boolean isEnum;

     private static final Bridge bridge =

         AccessController.doPrivileged(

             new PrivilegedAction<Bridge>() {

                 public Bridge run() {

                     return Bridge.get() ;

                 }

             }

         ) ;

     /** Find the descriptor for a class that can be serialized.  Null

      * is returned if the specified class does not implement

      * java.io.Serializable or java.io.Externalizable.

      */

     static final ObjectStreamClass lookup(Class<?> cl)

     {

         ObjectStreamClass desc = lookupInternal(cl);

         if (desc.isSerializable() || desc.isExternalizable())

             return desc;

         return null;

     }

     /*

      * Find the class descriptor for the specified class.

      * Package access only so it can be called from ObjectIn/OutStream.

      */

     static ObjectStreamClass lookupInternal(Class<?> cl)

     {

         /* Synchronize on the hashtable so no two threads will do

          * this at the same time.

          */

         ObjectStreamClass desc = null;

         synchronized (descriptorFor) {

             /* Find the matching descriptor if it already known */

             desc = findDescriptorFor(cl);

             if (desc == null) {

                 /* Check if it's serializable */

                 boolean serializable = Serializable.class.isAssignableFrom(cl);

                 /* If the class is only Serializable,

                  * lookup the descriptor for the superclass.

                  */

                 ObjectStreamClass superdesc = null;

                 if (serializable) {

                     Class<?> superclass = cl.getSuperclass();

                     if (superclass != null)

                         superdesc = lookup(superclass);

                 }

                 /* Check if its' externalizable.

                  * If it's Externalizable, clear the serializable flag.

                  * Only one or the other may be set in the protocol.

                  */

                 boolean externalizable = false;

                 if (serializable) {

                     externalizable =

                         ((superdesc != null) && superdesc.isExternalizable()) ||

                         Externalizable.class.isAssignableFrom(cl);

                     if (externalizable) {

                         serializable = false;

                     }

                 }

                 /* Create a new version descriptor,

                  * it put itself in the known table.

                  */

                 desc = new ObjectStreamClass(cl, superdesc,

                                              serializable, externalizable);

             }

             // Must always call init.  See bug 4488137.  This code was

             // incorrectly changed to return immediately on a non-null

             // cache result.  That allowed threads to gain access to

             // unintialized instances.

             //

             // History: Note, the following init() call was originally within

             // the synchronization block, as it currently is now. Later, the

             // init() call was moved outside the synchronization block, and

             // the init() method used a private member variable lock, to

             // avoid performance problems. See bug 4165204. But that lead to

             // a deadlock situation, see bug 5104239. Hence, the init() method

             // has now been moved back into the synchronization block. The

             // right approach to solving these problems would be to rewrite

             // this class, based on the latest java.io.ObjectStreamClass.

             desc.init();

         }

         return desc;

     }

     /**

      * The name of the class described by this descriptor.

      */

     public final String getName() {

         return name;

     }

     /**

      * Return the serialVersionUID for this class.

      * The serialVersionUID defines a set of classes all with the same name

      * that have evolved from a common root class and agree to be serialized

      * and deserialized using a common format.

      */

     public static final long getSerialVersionUID( java.lang.Class<?> clazz) {

         ObjectStreamClass theosc = ObjectStreamClass.lookup( clazz );

         if( theosc != null )

         {

                 return theosc.getSerialVersionUID( );

         }

         return 0;

     }

     /**

      * Return the serialVersionUID for this class.

      * The serialVersionUID defines a set of classes all with the same name

      * that have evolved from a common root class and agree to be serialized

      * and deserialized using a common format.

      */

     public final long getSerialVersionUID() {

         return suid;

     }

     /**

      * Return the serialVersionUID string for this class.

      * The serialVersionUID defines a set of classes all with the same name

      * that have evolved from a common root class and agree to be serialized

      * and deserialized using a common format.

      */

     public final String getSerialVersionUIDStr() {

         if (suidStr == null)

             suidStr = Long.toHexString(suid).toUpperCase();

         return suidStr;

     }

     /**

      * Return the actual (computed) serialVersionUID for this class.

      */

     public static final long getActualSerialVersionUID( java.lang.Class<?> clazz )

     {

         ObjectStreamClass theosc = ObjectStreamClass.lookup( clazz );

         if( theosc != null )

         {

                 return theosc.getActualSerialVersionUID( );

         }

         return 0;

     }

     /**

      * Return the actual (computed) serialVersionUID for this class.

      */

     public final long getActualSerialVersionUID() {

         return actualSuid;

     }

     /**

      * Return the actual (computed) serialVersionUID for this class.

      */

     public final String getActualSerialVersionUIDStr() {

         if (actualSuidStr == null)

             actualSuidStr = Long.toHexString(actualSuid).toUpperCase();

         return actualSuidStr;

     }

     /**

      * Return the class in the local VM that this version is mapped to.

      * Null is returned if there is no corresponding local class.

      */

     public final Class<?> forClass() {

         return ofClass;

     }

     /**

      * Return an array of the fields of this serializable class.

      * @return an array containing an element for each persistent

      * field of this class. Returns an array of length zero if

      * there are no fields.

      * @since JDK1.2

      */

     public ObjectStreamField[] getFields() {

         // Return a copy so the caller can't change the fields.

         if (fields.length > 0) {

             ObjectStreamField[] dup = new ObjectStreamField[fields.length];

             System.arraycopy(fields, 0, dup, 0, fields.length);

             return dup;

         } else {

             return fields;

         }

     }

     public boolean hasField(ValueMember field)

     {

         try {

             for (int i = 0; i < fields.length; i++) {

                 if (fields[i].getName().equals(field.name)) {

                     if (fields[i].getSignature().equals(

                         ValueUtility.getSignature(field)))

                         return true;

                 }

             }

         } catch (Exception exc) {

             // Ignore this; all we want to do is return false

             // Note that ValueUtility.getSignature can throw checked exceptions.

         }

         return false;

     }

     /* Avoid unnecessary allocations. */

     final ObjectStreamField[] getFieldsNoCopy() {

         return fields;

     }

     /**

      * Get the field of this class by name.

      * @return The ObjectStreamField object of the named field or null if there

      * is no such named field.

      */

     public final ObjectStreamField getField(String name) {

         /* Binary search of fields by name.

          */

         for (int i = fields.length-1; i >= 0; i--) {

             if (name.equals(fields[i].getName())) {

                 return fields[i];

             }

         }

         return null;

     }

     public Serializable writeReplace(Serializable value) {

         if (writeReplaceObjectMethod != null) {

             try {

                 return (Serializable) writeReplaceObjectMethod.invoke(value,noArgsList);

             } catch(Throwable t) {

                 throw new RuntimeException(t);

             }

         }

         else return value;

     }

     public Object readResolve(Object value) {

         if (readResolveObjectMethod != null) {

             try {

                 return readResolveObjectMethod.invoke(value,noArgsList);

             } catch(Throwable t) {

                 throw new RuntimeException(t);

             }

         }

         else return value;

     }

     /**

      * Return a string describing this ObjectStreamClass.

      */

     public final String toString() {

         StringBuffer sb = new StringBuffer();

         sb.append(name);

         sb.append(": static final long serialVersionUID = ");

         sb.append(Long.toString(suid));

         sb.append("L;");

         return sb.toString();

     }

     /*

      * Create a new ObjectStreamClass from a loaded class.

      * Don't call this directly, call lookup instead.

      */

     private ObjectStreamClass(java.lang.Class<?> cl, ObjectStreamClass superdesc,

                               boolean serial, boolean extern)

     {

         ofClass = cl;           /* created from this class */

         if (Proxy.isProxyClass(cl)) {

             forProxyClass = true;

         }

         name = cl.getName();

         isEnum = Enum.class.isAssignableFrom(cl);

         superclass = superdesc;

         serializable = serial;

         if (!forProxyClass) {

             // proxy classes are never externalizable

             externalizable = extern;

         }

         /*

          * Enter this class in the table of known descriptors.

          * Otherwise, when the fields are read it may recurse

          * trying to find the descriptor for itself.

          */

         insertDescriptorFor(this);

         /*

          * The remainder of initialization occurs in init(), which is called

          * after the lock on the global class descriptor table has been

          * released.

          */

     }

     private static final class PersistentFieldsValue

             extends ClassValue<ObjectStreamField[]> {

         PersistentFieldsValue() { }

         protected ObjectStreamField[] computeValue(Class<?> type) {

             try {

                 Field pf = type.getDeclaredField("serialPersistentFields");

                 int mods = pf.getModifiers();

                 if (Modifier.isPrivate(mods) && Modifier.isStatic(mods) &&

                         Modifier.isFinal(mods)) {

                     pf.setAccessible(true);

                     java.io.ObjectStreamField[] fields =

                         (java.io.ObjectStreamField[])pf.get(type);

                     return translateFields(fields);

                 }

             } catch (NoSuchFieldException | IllegalAccessException |

                     IllegalArgumentException | ClassCastException e) {

             }

             return null;

         }

         private static ObjectStreamField[] translateFields(

             java.io.ObjectStreamField[] fields) {

             ObjectStreamField[] translation =

                 new ObjectStreamField[fields.length];

             for (int i = 0; i < fields.length; i++) {

                 translation[i] = new ObjectStreamField(fields[i].getName(),

                         fields[i].getType());

             }

             return translation;

         }

     }

     private static final PersistentFieldsValue persistentFieldsValue =

         new PersistentFieldsValue();

     /*

      * Initialize class descriptor.  This method is only invoked on class

      * descriptors created via calls to lookupInternal().  This method is kept

      * separate from the ObjectStreamClass constructor so that lookupInternal

      * does not have to hold onto a global class descriptor table lock while the

      * class descriptor is being initialized (see bug 4165204).

      */

     private void init() {

       synchronized (lock) {

         // See description at definition of initialized.

         if (initialized)

             return;

         final Class<?> cl = ofClass;

         if (!serializable ||

             externalizable ||

             forProxyClass ||

             name.equals("java.lang.String")){

             fields = NO_FIELDS;

         } else if (serializable) {

             /* Ask for permission to override field access checks.

              */

             AccessController.doPrivileged(new PrivilegedAction() {

                 public Object run() {

                 /* Fill in the list of persistent fields.

                  * If it is declared, use the declared serialPersistentFields.

                  * Otherwise, extract the fields from the class itself.

                  */

                     fields = persistentFieldsValue.get(cl);

                 if (fields == null) {

                     /* Get all of the declared fields for this

                      * Class. setAccessible on all fields so they

                      * can be accessed later.  Create a temporary

                      * ObjectStreamField array to hold each

                      * non-static, non-transient field. Then copy the

                      * temporary array into an array of the correct

                      * size once the number of fields is known.

                      */

                     Field[] actualfields = cl.getDeclaredFields();

                     int numFields = 0;

                     ObjectStreamField[] tempFields =

                         new ObjectStreamField[actualfields.length];

                     for (int i = 0; i < actualfields.length; i++) {

                         Field fld = actualfields[i] ;

                         int modifiers = fld.getModifiers();

                         if (!Modifier.isStatic(modifiers) &&

                             !Modifier.isTransient(modifiers)) {

                             fld.setAccessible(true) ;

                             tempFields[numFields++] = new ObjectStreamField(fld);

                         }

                     }

                     fields = new ObjectStreamField[numFields];

                     System.arraycopy(tempFields, 0, fields, 0, numFields);

                 } else {

                     // For each declared persistent field, look for an actual

                     // reflected Field. If there is one, make sure it's the correct

                     // type and cache it in the ObjectStreamClass for that field.

                     for (int j = fields.length-1; j >= 0; j--) {

                         try {

                             Field reflField = cl.getDeclaredField(fields[j].getName());

                             if (fields[j].getType() == reflField.getType()) {

                                 reflField.setAccessible(true);

                                 fields[j].setField(reflField);

                             }

                         } catch (NoSuchFieldException e) {

                             // Nothing to do

                         }

                     }

                 }

                 return null;

             }

             });

             if (fields.length > 1)

                 Arrays.sort(fields);

             /* Set up field data for use while writing using the API api. */

             computeFieldInfo();

         }

         /* Get the serialVersionUID from the class.

          * It uses the access override mechanism so make sure

          * the field objects is only used here.

          *

          * NonSerializable classes have a serialVerisonUID of 0L.

          */

          if (isNonSerializable() || isEnum) {

              suid = 0L;

          } else {

              // Lookup special Serializable members using reflection.

              AccessController.doPrivileged(new PrivilegedAction() {

                 public Object run() {

                 if (forProxyClass) {

                     // proxy classes always have serialVersionUID of 0L

                     suid = 0L;

                 } else {

                     try {

                         final Field f = cl.getDeclaredField("serialVersionUID");

                         int mods = f.getModifiers();

                         // SerialBug 5:  static final SUID should be read

                         if (Modifier.isStatic(mods) && Modifier.isFinal(mods) ) {

                             f.setAccessible(true);

                             suid = f.getLong(cl);

                             // SerialBug 2: should be computed after writeObject

                             // actualSuid = computeStructuralUID(cl);

                         } else {

                             suid = _computeSerialVersionUID(cl);

                             // SerialBug 2: should be computed after writeObject

                             // actualSuid = computeStructuralUID(cl);

                         }

                     } catch (NoSuchFieldException ex) {

                         suid = _computeSerialVersionUID(cl);

                         // SerialBug 2: should be computed after writeObject

                         // actualSuid = computeStructuralUID(cl);

                     } catch (IllegalAccessException ex) {

                         suid = _computeSerialVersionUID(cl);

                     }

                 }

                 writeReplaceObjectMethod = ObjectStreamClass.getInheritableMethod(cl,

                     "writeReplace", noTypesList, Object.class);

                 readResolveObjectMethod = ObjectStreamClass.getInheritableMethod(cl,

                     "readResolve", noTypesList, Object.class);

                 if (externalizable)

                     cons = getExternalizableConstructor(cl) ;

                 else

                     cons = getSerializableConstructor(cl) ;

                 if (serializable && !forProxyClass) {

                     /* Look for the writeObject method

                      * Set the accessible flag on it here. ObjectOutputStream

                      * will call it as necessary.

                      */

                     writeObjectMethod = getPrivateMethod( cl, "writeObject",

                         new Class<?>[] { java.io.ObjectOutputStream.class }, Void.TYPE ) ;

                     readObjectMethod = getPrivateMethod( cl, "readObject",

                         new Class<?>[] { java.io.ObjectInputStream.class }, Void.TYPE ) ;

                 }

                 return null;

             }

           });

         }

         // This call depends on a lot of information computed above!

         actualSuid = ObjectStreamClass.computeStructuralUID(this, cl);

         // If we have a write object method, precompute the

         // RMI-IIOP stream format version 2 optional data

         // repository ID.

         if (hasWriteObject())

             rmiiiopOptionalDataRepId = computeRMIIIOPOptionalDataRepId();

         // This must be done last.

         initialized = true;

       }

     }

     /**

      * Returns non-static private method with given signature defined by given

      * class, or null if none found.  Access checks are disabled on the

      * returned method (if any).

      */

     private static Method getPrivateMethod(Class<?> cl, String name,

                                            Class<?>[] argTypes,

                                            Class<?> returnType)

     {

         try {

             Method meth = cl.getDeclaredMethod(name, argTypes);

             meth.setAccessible(true);

             int mods = meth.getModifiers();

             return ((meth.getReturnType() == returnType) &&

                     ((mods & Modifier.STATIC) == 0) &&

                     ((mods & Modifier.PRIVATE) != 0)) ? meth : null;

         } catch (NoSuchMethodException ex) {

             return null;

         }

     }

     // Specific to RMI-IIOP

     /**

      * Java to IDL ptc-02-01-12 1.5.1

      *

      * "The rep_id string passed to the start_value method must be

      * 'RMI:org.omg.custom.class:hashcode:suid' where class is the

      * fully-qualified name of the class whose writeObject method

      * is being invoked and hashcode and suid are the class's hashcode

      * and SUID."

      */

     private String computeRMIIIOPOptionalDataRepId() {

         StringBuffer sbuf = new StringBuffer("RMI:org.omg.custom.");

         sbuf.append(RepositoryId.convertToISOLatin1(this.getName()));

         sbuf.append(':');

         sbuf.append(this.getActualSerialVersionUIDStr());

         sbuf.append(':');

         sbuf.append(this.getSerialVersionUIDStr());

         return sbuf.toString();

     }

     /**

      * This will return null if there is no writeObject method.

      */

     public final String getRMIIIOPOptionalDataRepId() {

         return rmiiiopOptionalDataRepId;

     }

     /*

      * Create an empty ObjectStreamClass for a class about to be read.

      * This is separate from read so ObjectInputStream can assign the

      * wire handle early, before any nested ObjectStreamClass might

      * be read.

      */

     ObjectStreamClass(String n, long s) {

         name = n;

         suid = s;

         superclass = null;

     }

     /*

      * Set the class this version descriptor matches.

      * The base class name and serializable hash must match.

      * Fill in the reflected Fields that will be used

      * for reading.

      */

     final void setClass(Class<?> cl) throws InvalidClassException {

         if (cl == null) {

             localClassDesc = null;

             ofClass = null;

             computeFieldInfo();

             return;

         }

         localClassDesc = lookupInternal(cl);

         if (localClassDesc == null)

             // XXX I18N, logging needed

             throw new InvalidClassException(cl.getName(),

                                             "Local class not compatible");

         if (suid != localClassDesc.suid) {

             /* Check for exceptional cases that allow mismatched suid. */

             /* Allow adding Serializable or Externalizable

              * to a later release of the class.

              */

             boolean addedSerialOrExtern =

                 isNonSerializable() || localClassDesc.isNonSerializable();

             /* Disregard the serialVersionUID of an array

              * when name and cl.Name differ. If resolveClass() returns

              * an array with a different package name,

              * the serialVersionUIDs will not match since the fully

              * qualified array class is used in the

              * computation of the array's serialVersionUID. There is

              * no way to set a permanent serialVersionUID for an array type.

              */

             boolean arraySUID = (cl.isArray() && ! cl.getName().equals(name));

             if (! arraySUID && ! addedSerialOrExtern ) {

                 // XXX I18N, logging needed

                 throw new InvalidClassException(cl.getName(),

                                                 "Local class not compatible:" +

                                                 " stream classdesc serialVersionUID=" + suid +

                                                 " local class serialVersionUID=" + localClassDesc.suid);

             }

         }

         /* compare the class names, stripping off package names. */

         if (! compareClassNames(name, cl.getName(), '.'))

             // XXX I18N, logging needed

             throw new InvalidClassException(cl.getName(),

                          "Incompatible local class name. " +

                          "Expected class name compatible with " +

                          name);

         /*

          * Test that both implement either serializable or externalizable.

          */

         // The next check is more generic, since it covers the

         // Proxy case, the JDK 1.3 serialization code has

         // both checks

         //if ((serializable && localClassDesc.externalizable) ||

         //    (externalizable && localClassDesc.serializable))

         //    throw new InvalidClassException(localCl.getName(),

         //            "Serializable is incompatible with Externalizable");

         if ((serializable != localClassDesc.serializable) ||

             (externalizable != localClassDesc.externalizable) ||

             (!serializable && !externalizable))

             // XXX I18N, logging needed

             throw new InvalidClassException(cl.getName(),

                                             "Serialization incompatible with Externalization");

         /* Set up the reflected Fields in the class where the value of each

          * field in this descriptor should be stored.

          * Each field in this ObjectStreamClass (the source) is located (by

          * name) in the ObjectStreamClass of the class(the destination).

          * In the usual (non-versioned case) the field is in both

          * descriptors and the types match, so the reflected Field is copied.

          * If the type does not match, a InvalidClass exception is thrown.

          * If the field is not present in the class, the reflected Field

          * remains null so the field will be read but discarded.

          * If extra fields are present in the class they are ignored. Their

          * values will be set to the default value by the object allocator.

          * Both the src and dest field list are sorted by type and name.

          */

         ObjectStreamField[] destfield =

             (ObjectStreamField[])localClassDesc.fields;

         ObjectStreamField[] srcfield =

             (ObjectStreamField[])fields;

         int j = 0;

     nextsrc:

         for (int i = 0; i < srcfield.length; i++ ) {

             /* Find this field in the dest*/

             for (int k = j; k < destfield.length; k++) {

                 if (srcfield[i].getName().equals(destfield[k].getName())) {

                     /* found match */

                     if (srcfield[i].isPrimitive() &&

                         !srcfield[i].typeEquals(destfield[k])) {

                         // XXX I18N, logging needed

                         throw new InvalidClassException(cl.getName(),

                                                         "The type of field " +

                                                         srcfield[i].getName() +

                                                         " of class " + name +

                                                         " is incompatible.");

                     }

                     /* Skip over any fields in the dest that are not in the src */

                     j = k;

                     srcfield[i].setField(destfield[j].getField());

                     // go on to the next source field

                     continue nextsrc;

                 }

             }

         }

         /* Set up field data for use while reading from the input stream. */

         computeFieldInfo();

         /* Remember the class this represents */

         ofClass = cl;

         /* get the cache of these methods from the local class

          * implementation.

          */

         readObjectMethod = localClassDesc.readObjectMethod;

         readResolveObjectMethod = localClassDesc.readResolveObjectMethod;

     }

     /* Compare the base class names of streamName and localName.

      *

      * @return  Return true iff the base class name compare.

      * @parameter streamName    Fully qualified class name.

      * @parameter localName     Fully qualified class name.

      * @parameter pkgSeparator  class names use either '.' or '/'.

      *

      * Only compare base class name to allow package renaming.

      */

     static boolean compareClassNames(String streamName,

                                      String localName,

                                      char pkgSeparator) {

         /* compare the class names, stripping off package names. */

         int streamNameIndex = streamName.lastIndexOf(pkgSeparator);

         if (streamNameIndex < 0)

             streamNameIndex = 0;

         int localNameIndex = localName.lastIndexOf(pkgSeparator);

         if (localNameIndex < 0)

             localNameIndex = 0;

         return streamName.regionMatches(false, streamNameIndex,

                                         localName, localNameIndex,

                                         streamName.length() - streamNameIndex);

     }

     /*

      * Compare the types of two class descriptors.

      * They match if they have the same class name and suid

      */

     final boolean typeEquals(ObjectStreamClass other) {

         return (suid == other.suid) &&

             compareClassNames(name, other.name, '.');

     }

     /*

      * Return the superclass descriptor of this descriptor.

      */

     final void setSuperclass(ObjectStreamClass s) {

         superclass = s;

     }

     /*

      * Return the superclass descriptor of this descriptor.

      */

     final ObjectStreamClass getSuperclass() {

         return superclass;

     }

     /**

      * Return whether the class has a readObject method

      */

     final boolean hasReadObject() {

         return readObjectMethod != null;

     }

     /*

      * Return whether the class has a writeObject method

      */

     final boolean hasWriteObject() {

         return writeObjectMethod != null ;

     }

     /**

      * Returns when or not this class should be custom

      * marshaled (use chunking).  This should happen if

      * it is Externalizable OR if it or

      * any of its superclasses has a writeObject method,

      */

     final boolean isCustomMarshaled() {

         return (hasWriteObject() || isExternalizable())

             || (superclass != null && superclass.isCustomMarshaled());

     }

     /*

      * Return true if all instances of 'this' Externalizable class

      * are written in block-data mode from the stream that 'this' was read

      * from. <p>

      *

      * In JDK 1.1, all Externalizable instances are not written

      * in block-data mode.

      * In JDK 1.2, all Externalizable instances, by default, are written

      * in block-data mode and the Externalizable instance is terminated with

      * tag TC_ENDBLOCKDATA. Change enabled the ability to skip Externalizable

      * instances.

      *

      * IMPLEMENTATION NOTE:

      *   This should have been a mode maintained per stream; however,

      *   for compatibility reasons, it was only possible to record

      *   this change per class. All Externalizable classes within

      *   a given stream should either have this mode enabled or

      *   disabled. This is enforced by not allowing the PROTOCOL_VERSION

      *   of a stream to he changed after any objects have been written.

      *

      * @see ObjectOutputStream#useProtocolVersion

      * @see ObjectStreamConstants#PROTOCOL_VERSION_1

      * @see ObjectStreamConstants#PROTOCOL_VERSION_2

      *

      * @since JDK 1.2

      */

     boolean hasExternalizableBlockDataMode() {

         return hasExternalizableBlockData;

     }

     /**

      * Creates a new instance of the represented class.  If the class is

      * externalizable, invokes its public no-arg constructor; otherwise, if the

      * class is serializable, invokes the no-arg constructor of the first

      * non-serializable superclass.  Throws UnsupportedOperationException if

      * this class descriptor is not associated with a class, if the associated

      * class is non-serializable or if the appropriate no-arg constructor is

      * inaccessible/unavailable.

      */

     Object newInstance()

         throws InstantiationException, InvocationTargetException,

                UnsupportedOperationException

     {

         if (cons != null) {

             try {

                 return cons.newInstance(new Object[0]);

             } catch (IllegalAccessException ex) {

                 // should not occur, as access checks have been suppressed

                 InternalError ie = new InternalError();

                 ie.initCause( ex ) ;

                 throw ie ;

             }

         } else {

             throw new UnsupportedOperationException();

         }

     }

     /**

      * Returns public no-arg constructor of given class, or null if none found.

      * Access checks are disabled on the returned constructor (if any), since

      * the defining class may still be non-public.

      */

     private static Constructor getExternalizableConstructor(Class<?> cl) {

         try {

             Constructor cons = cl.getDeclaredConstructor(new Class<?>[0]);

             cons.setAccessible(true);

             return ((cons.getModifiers() & Modifier.PUBLIC) != 0) ?

                 cons : null;

         } catch (NoSuchMethodException ex) {

             return null;

         }

     }

     /**

      * Returns subclass-accessible no-arg constructor of first non-serializable

      * superclass, or null if none found.  Access checks are disabled on the

      * returned constructor (if any).

      */

     private static Constructor getSerializableConstructor(Class<?> cl) {

         Class<?> initCl = cl;

         while (Serializable.class.isAssignableFrom(initCl)) {

             if ((initCl = initCl.getSuperclass()) == null) {

                 return null;

             }

         }

         try {

             Constructor cons = initCl.getDeclaredConstructor(new Class<?>[0]);

             int mods = cons.getModifiers();

             if ((mods & Modifier.PRIVATE) != 0 ||

                 ((mods & (Modifier.PUBLIC | Modifier.PROTECTED)) == 0 &&

                  !packageEquals(cl, initCl)))

             {

                 return null;

             }

             cons = bridge.newConstructorForSerialization(cl, cons);

             cons.setAccessible(true);

             return cons;

         } catch (NoSuchMethodException ex) {

             return null;

         }

     }

     /*

      * Return the ObjectStreamClass of the local class this one is based on.

      */

     final ObjectStreamClass localClassDescriptor() {

         return localClassDesc;

     }

     /*

      * Get the Serializability of the class.

      */

     boolean isSerializable() {

         return serializable;

     }

     /*

      * Get the externalizability of the class.

      */

     boolean isExternalizable() {

         return externalizable;

     }

     boolean isNonSerializable() {

         return ! (externalizable || serializable);

     }

     /*

      * Calculate the size of the array needed to store primitive data and the

      * number of object references to read when reading from the input

      * stream.

      */

     private void computeFieldInfo() {

         primBytes = 0;

         objFields = 0;

         for (int i = 0; i < fields.length; i++ ) {

             switch (fields[i].getTypeCode()) {

             case 'B':

             case 'Z':

                 primBytes += 1;

                 break;

             case 'C':

             case 'S':

                 primBytes += 2;

                 break;

             case 'I':

             case 'F':

                 primBytes += 4;

                 break;

             case 'J':

             case 'D' :

                 primBytes += 8;

                 break;

             case 'L':

             case '[':

                 objFields += 1;

                 break;

             }

         }

     }

     private static void msg( String str )

     {

         System.out.println( str ) ;

     }

     /* JDK 1.5 has introduced some new modifier bits (such as SYNTHETIC)

      * that can affect the SVUID computation (see bug 4897937).  These bits

      * must be ignored, as otherwise interoperability with ORBs in earlier

      * JDK versions can be compromised.  I am adding these masks for this

      * purpose as discussed in the CCC for this bug (see http://ccc.sfbay/4897937).

      */

     public static final int CLASS_MASK = Modifier.PUBLIC | Modifier.FINAL |

         Modifier.INTERFACE | Modifier.ABSTRACT ;

     public static final int FIELD_MASK = Modifier.PUBLIC | Modifier.PRIVATE |

         Modifier.PROTECTED | Modifier.STATIC | Modifier.FINAL |

         Modifier.TRANSIENT | Modifier.VOLATILE ;

     public static final int METHOD_MASK = Modifier.PUBLIC | Modifier.PRIVATE |

         Modifier.PROTECTED | Modifier.STATIC | Modifier.FINAL |

         Modifier.SYNCHRONIZED | Modifier.NATIVE | Modifier.ABSTRACT |

         Modifier.STRICT ;

     /*

      * Compute a hash for the specified class.  Incrementally add

      * items to the hash accumulating in the digest stream.

      * Fold the hash into a long.  Use the SHA secure hash function.

      */

     private static long _computeSerialVersionUID(Class<?> cl) {

         if (DEBUG_SVUID)

             msg( "Computing SerialVersionUID for " + cl ) ;

         ByteArrayOutputStream devnull = new ByteArrayOutputStream(512);

         long h = 0;

         try {

             MessageDigest md = MessageDigest.getInstance("SHA");

             DigestOutputStream mdo = new DigestOutputStream(devnull, md);

             DataOutputStream data = new DataOutputStream(mdo);

             if (DEBUG_SVUID)

                 msg( "\twriteUTF( \"" + cl.getName() + "\" )" ) ;

             data.writeUTF(cl.getName());

             int classaccess = cl.getModifiers();

             classaccess &= (Modifier.PUBLIC | Modifier.FINAL |

                             Modifier.INTERFACE | Modifier.ABSTRACT);

             /* Workaround for javac bug that only set ABSTRACT for

              * interfaces if the interface had some methods.

              * The ABSTRACT bit reflects that the number of methods > 0.

              * This is required so correct hashes can be computed

              * for existing class files.

              * Previously this hack was previously present in the VM.

              */

             Method[] method = cl.getDeclaredMethods();

             if ((classaccess & Modifier.INTERFACE) != 0) {

                 classaccess &= (~Modifier.ABSTRACT);

                 if (method.length > 0) {

                     classaccess |= Modifier.ABSTRACT;

                 }

             }

             // Mask out any post-1.4 attributes

             classaccess &= CLASS_MASK ;

             if (DEBUG_SVUID)

                 msg( "\twriteInt( " + classaccess + " ) " ) ;

             data.writeInt(classaccess);

             /*

              * Get the list of interfaces supported,

              * Accumulate their names their names in Lexical order

              * and add them to the hash

              */

             if (!cl.isArray()) {

                 /* In 1.2fcs, getInterfaces() was modified to return

                  * {java.lang.Cloneable, java.io.Serializable} when

                  * called on array classes.  These values would upset

                  * the computation of the hash, so we explicitly omit

                  * them from its computation.

                  */

                 Class<?> interfaces[] = cl.getInterfaces();

                 Arrays.sort(interfaces, compareClassByName);

                 for (int i = 0; i < interfaces.length; i++) {

                     if (DEBUG_SVUID)

                         msg( "\twriteUTF( \"" + interfaces[i].getName() + "\" ) " ) ;

                     data.writeUTF(interfaces[i].getName());

                 }

             }

             /* Sort the field names to get a deterministic order */

             Field[] field = cl.getDeclaredFields();

             Arrays.sort(field, compareMemberByName);

             for (int i = 0; i < field.length; i++) {

                 Field f = field[i];

                 /* Include in the hash all fields except those that are

                  * private transient and private static.

                  */

                 int m = f.getModifiers();

                 if (Modifier.isPrivate(m) &&

                     (Modifier.isTransient(m) || Modifier.isStatic(m)))

                     continue;

                 if (DEBUG_SVUID)

                     msg( "\twriteUTF( \"" + f.getName() + "\" ) " ) ;

                 data.writeUTF(f.getName());

                 // Mask out any post-1.4 bits

                 m &= FIELD_MASK ;

                 if (DEBUG_SVUID)

                     msg( "\twriteInt( " + m + " ) " ) ;

                 data.writeInt(m);

                 if (DEBUG_SVUID)

                     msg( "\twriteUTF( \"" + getSignature(f.getType()) + "\" ) " ) ;

                 data.writeUTF(getSignature(f.getType()));

             }

             if (hasStaticInitializer(cl)) {

                 if (DEBUG_SVUID)

                     msg( "\twriteUTF( \"<clinit>\" ) " ) ;

                 data.writeUTF("<clinit>");

                 if (DEBUG_SVUID)

                     msg( "\twriteInt( " + Modifier.STATIC + " )" ) ;

                 data.writeInt(Modifier.STATIC); // TBD: what modifiers does it have

                 if (DEBUG_SVUID)

                     msg( "\twriteUTF( \"()V\" )" ) ;

                 data.writeUTF("()V");

             }

             /*

              * Get the list of constructors including name and signature

              * Sort lexically, add all except the private constructors

              * to the hash with their access flags

              */

             MethodSignature[] constructors =

                 MethodSignature.removePrivateAndSort(cl.getDeclaredConstructors());

             for (int i = 0; i < constructors.length; i++) {

                 MethodSignature c = constructors[i];

                 String mname = "<init>";

                 String desc = c.signature;

                 desc = desc.replace('/', '.');

                 if (DEBUG_SVUID)

                     msg( "\twriteUTF( \"" + mname + "\" )" ) ;

                 data.writeUTF(mname);

                 // mask out post-1.4 modifiers

                 int modifier = c.member.getModifiers() & METHOD_MASK ;

                 if (DEBUG_SVUID)

                     msg( "\twriteInt( " + modifier + " ) " ) ;

                 data.writeInt( modifier ) ;

                 if (DEBUG_SVUID)

                     msg( "\twriteUTF( \"" + desc+ "\" )" ) ;

                 data.writeUTF(desc);

             }

             /* Include in the hash all methods except those that are

              * private transient and private static.

              */

             MethodSignature[] methods =

                 MethodSignature.removePrivateAndSort(method);

             for (int i = 0; i < methods.length; i++ ) {

                 MethodSignature m = methods[i];

                 String desc = m.signature;

                 desc = desc.replace('/', '.');

                 if (DEBUG_SVUID)

                     msg( "\twriteUTF( \"" + m.member.getName()+ "\" )" ) ;

                 data.writeUTF(m.member.getName());

                 // mask out post-1.4 modifiers

                 int modifier = m.member.getModifiers() & METHOD_MASK ;

                 if (DEBUG_SVUID)

                     msg( "\twriteInt( " + modifier + " ) " ) ;

                 data.writeInt( modifier ) ;

                 if (DEBUG_SVUID)

                     msg( "\twriteUTF( \"" + desc + "\" )" ) ;

                 data.writeUTF(desc);

             }

             /* Compute the hash value for this class.

              * Use only the first 64 bits of the hash.

              */

             data.flush();

             byte hasharray[] = md.digest();

             for (int i = 0; i < Math.min(8, hasharray.length); i++) {

                 h += (long)(hasharray[i] & 255) << (i * 8);

             }

         } catch (IOException ignore) {

             /* can't happen, but be deterministic anyway. */

             h = -1;

         } catch (NoSuchAlgorithmException complain) {

             SecurityException se = new SecurityException() ;

             se.initCause( complain ) ;

             throw se ;

         }

         return h;

     }

     private static long computeStructuralUID(com.sun.corba.se.impl.io.ObjectStreamClass osc, Class<?> cl) {

         ByteArrayOutputStream devnull = new ByteArrayOutputStream(512);

         long h = 0;

         try {

             if ((!java.io.Serializable.class.isAssignableFrom(cl)) ||

                 (cl.isInterface())){

                 return 0;

             }

             if (java.io.Externalizable.class.isAssignableFrom(cl)) {

                 return 1;

             }

             MessageDigest md = MessageDigest.getInstance("SHA");

             DigestOutputStream mdo = new DigestOutputStream(devnull, md);

             DataOutputStream data = new DataOutputStream(mdo);

             // Get SUID of parent

             Class<?> parent = cl.getSuperclass();

             if ((parent != null))

             // SerialBug 1; acc. to spec the one for

             // java.lang.object

             // should be computed and put

             //     && (parent != java.lang.Object.class))

             {

                                 //data.writeLong(computeSerialVersionUID(null,parent));

                 data.writeLong(computeStructuralUID(lookup(parent), parent));

             }

             if (osc.hasWriteObject())

                 data.writeInt(2);

             else

                 data.writeInt(1);

             // CORBA formal 00-11-03 10.6.2:  For each field of the

             // class that is mapped to IDL, sorted lexicographically

             // by Java field name, in increasing order...

             ObjectStreamField[] field = osc.getFields();

             if (field.length > 1) {

                 Arrays.sort(field, compareObjStrFieldsByName);

             }

             // ...Java field name in UTF encoding, field

             // descriptor, as defined by the JVM spec...

             for (int i = 0; i < field.length; i++) {

                 data.writeUTF(field[i].getName());

                 data.writeUTF(field[i].getSignature());

             }

             /* Compute the hash value for this class.

              * Use only the first 64 bits of the hash.

              */

             data.flush();

             byte hasharray[] = md.digest();

             // int minimum = Math.min(8, hasharray.length);

             // SerialBug 3: SHA computation is wrong; for loop reversed

             //for (int i = minimum; i > 0; i--)

             for (int i = 0; i < Math.min(8, hasharray.length); i++) {

                 h += (long)(hasharray[i] & 255) << (i * 8);

             }

         } catch (IOException ignore) {

             /* can't happen, but be deterministic anyway. */

             h = -1;

         } catch (NoSuchAlgorithmException complain) {

             SecurityException se = new SecurityException();

             se.initCause( complain ) ;

             throw se ;

         }

         return h;

     }

     /**

      * Compute the JVM signature for the class.

      */

     static String getSignature(Class<?> clazz) {

         String type = null;

         if (clazz.isArray()) {

             Class<?> cl = clazz;

             int dimensions = 0;

             while (cl.isArray()) {

                 dimensions++;

                 cl = cl.getComponentType();

             }

             StringBuffer sb = new StringBuffer();

             for (int i = 0; i < dimensions; i++) {

                 sb.append("[");

             }

             sb.append(getSignature(cl));

             type = sb.toString();

         } else if (clazz.isPrimitive()) {

             if (clazz == Integer.TYPE) {

                 type = "I";

             } else if (clazz == Byte.TYPE) {

                 type = "B";

             } else if (clazz == Long.TYPE) {

                 type = "J";

             } else if (clazz == Float.TYPE) {

                 type = "F";

             } else if (clazz == Double.TYPE) {

                 type = "D";

             } else if (clazz == Short.TYPE) {

                 type = "S";

             } else if (clazz == Character.TYPE) {

                 type = "C";

             } else if (clazz == Boolean.TYPE) {

                 type = "Z";

             } else if (clazz == Void.TYPE) {

                 type = "V";

             }

         } else {

             type = "L" + clazz.getName().replace('.', '/') + ";";

         }

         return type;

     }

     /*

      * Compute the JVM method descriptor for the method.

      */

     static String getSignature(Method meth) {

         StringBuffer sb = new StringBuffer();

         sb.append("(");

         Class<?>[] params = meth.getParameterTypes(); // avoid clone

         for (int j = 0; j < params.length; j++) {

             sb.append(getSignature(params[j]));

         }

         sb.append(")");

         sb.append(getSignature(meth.getReturnType()));

         return sb.toString();

     }

     /*

      * Compute the JVM constructor descriptor for the constructor.

      */

     static String getSignature(Constructor cons) {

         StringBuffer sb = new StringBuffer();

         sb.append("(");

         Class<?>[] params = cons.getParameterTypes(); // avoid clone

         for (int j = 0; j < params.length; j++) {

             sb.append(getSignature(params[j]));

         }

         sb.append(")V");

         return sb.toString();

     }

     /*

      * Cache of Class -> ClassDescriptor Mappings.

      */

     static private ObjectStreamClassEntry[] descriptorFor = new ObjectStreamClassEntry[61];

     /*

      * findDescriptorFor a Class.  This looks in the cache for a

      * mapping from Class -> ObjectStreamClass mappings.  The hashCode

      * of the Class is used for the lookup since the Class is the key.

      * The entries are extended from java.lang.ref.SoftReference so the

      * gc will be able to free them if needed.

      */

     private static ObjectStreamClass findDescriptorFor(Class<?> cl) {

         int hash = cl.hashCode();

         int index = (hash & 0x7FFFFFFF) % descriptorFor.length;

         ObjectStreamClassEntry e;

         ObjectStreamClassEntry prev;

         /* Free any initial entries whose refs have been cleared */

         while ((e = descriptorFor[index]) != null && e.get() == null) {

             descriptorFor[index] = e.next;

         }

         /* Traverse the chain looking for a descriptor with ofClass == cl.

          * unlink entries that are unresolved.

          */

         prev = e;

         while (e != null ) {

             ObjectStreamClass desc = (ObjectStreamClass)(e.get());

             if (desc == null) {

                 // This entry has been cleared,  unlink it

                 prev.next = e.next;

             } else {

                 if (desc.ofClass == cl)

                     return desc;

                 prev = e;

             }

             e = e.next;

         }

         return null;

     }

     /*

      * insertDescriptorFor a Class -> ObjectStreamClass mapping.

      */

     private static void insertDescriptorFor(ObjectStreamClass desc) {

         // Make sure not already present

         if (findDescriptorFor(desc.ofClass) != null) {

             return;

         }

         int hash = desc.ofClass.hashCode();

         int index = (hash & 0x7FFFFFFF) % descriptorFor.length;

         ObjectStreamClassEntry e = new ObjectStreamClassEntry(desc);

         e.next = descriptorFor[index];

         descriptorFor[index] = e;

     }

     private static Field[] getDeclaredFields(final Class<?> clz) {

         return (Field[]) AccessController.doPrivileged(new PrivilegedAction() {

             public Object run() {

                 return clz.getDeclaredFields();

             }

         });

     }

     /*

      * The name of this descriptor

      */

     private String name;

     /*

      * The descriptor of the supertype.

      */

     private ObjectStreamClass superclass;

     /*

      * Flags for Serializable and Externalizable.

      */

     private boolean serializable;

     private boolean externalizable;

     /*

      * Array of persistent fields of this class, sorted by

      * type and name.

      */

     private ObjectStreamField[] fields;

     /*

      * Class that is a descriptor for in this virtual machine.

      */

     private Class<?> ofClass;

     /*

      * True if descriptor for a proxy class.

      */

     boolean forProxyClass;

     /*

      * SerialVersionUID for this class.

      */

     private long suid = kDefaultUID;

     private String suidStr = null;

     /*

      * Actual (computed) SerialVersionUID for this class.

      */

     private long actualSuid = kDefaultUID;

     private String actualSuidStr = null;

     /*

      * The total number of bytes of primitive fields.

      * The total number of object fields.

      */

     int primBytes;

     int objFields;

     /**

      * Flag indicating whether or not this instance has

      * successfully completed initialization.  This is to

      * try to fix bug 4373844.  Working to move to

      * reusing java.io.ObjectStreamClass for JDK 1.5.

      */

     private boolean initialized = false;

     /* Internal lock object. */

     private Object lock = new Object();

     /* In JDK 1.1, external data was not written in block mode.

      * As of JDK 1.2, external data is written in block data mode. This

      * flag enables JDK 1.2 to be able to read JDK 1.1 written external data.

      *

      * @since JDK 1.2

      */

     private boolean hasExternalizableBlockData;

     Method writeObjectMethod;

     Method readObjectMethod;

     private transient Method writeReplaceObjectMethod;

     private transient Method readResolveObjectMethod;

     private Constructor cons ;

     /**

      * Beginning in Java to IDL ptc/02-01-12, RMI-IIOP has a

      * stream format version 2 which puts a fake valuetype around

      * a Serializable's optional custom data.  This valuetype has

      * a special repository ID made from the Serializable's

      * information which we are pre-computing and

      * storing here.

      */

     private String rmiiiopOptionalDataRepId = null;

     /*

      * ObjectStreamClass that this one was built from.

      */

     private ObjectStreamClass localClassDesc;

     /* Find out if the class has a static class initializer <clinit> */

     private static Method hasStaticInitializerMethod = null;

     /**

      * Returns true if the given class defines a static initializer method,

      * false otherwise.

      */

     private static boolean hasStaticInitializer(Class<?> cl) {

         if (hasStaticInitializerMethod == null) {

             Class<?> classWithThisMethod = null;

             try {

                 if (classWithThisMethod == null)

                     classWithThisMethod = java.io.ObjectStreamClass.class;

                 hasStaticInitializerMethod =

                     classWithThisMethod.getDeclaredMethod("hasStaticInitializer",

                                                           new Class<?>[] { Class.class });

             } catch (NoSuchMethodException ex) {

             }

             if (hasStaticInitializerMethod == null) {

                 // XXX I18N, logging needed

                 throw new InternalError("Can't find hasStaticInitializer method on "

                                         + classWithThisMethod.getName());

             }

             hasStaticInitializerMethod.setAccessible(true);

         }

         try {

             Boolean retval = (Boolean)

                 hasStaticInitializerMethod.invoke(null, new Object[] { cl });

             return retval.booleanValue();

         } catch (Exception ex) {

             // XXX I18N, logging needed

             InternalError ie = new InternalError( "Error invoking hasStaticInitializer" ) ;

             ie.initCause( ex ) ;

             throw ie ;

         }

     }

     /** use serialVersionUID from JDK 1.1. for interoperability */

     private static final long serialVersionUID = -6120832682080437368L;

     /**

      * Set serialPersistentFields of a Serializable class to this value to

      * denote that the class has no Serializable fields.

      */

     public static final ObjectStreamField[] NO_FIELDS =

         new ObjectStreamField[0];

     /*

      * Entries held in the Cache of known ObjectStreamClass objects.

      * Entries are chained together with the same hash value (modulo array size).

      */

     private static class ObjectStreamClassEntry // extends java.lang.ref.SoftReference

     {

         ObjectStreamClassEntry(ObjectStreamClass c) {

             //super(c);

             this.c = c;

         }

         ObjectStreamClassEntry next;

         public Object get()

         {

             return c;

         }

         private ObjectStreamClass c;

     }

     /*

      * Comparator object for Classes and Interfaces

      */

     private static Comparator compareClassByName =

         new CompareClassByName();

     private static class CompareClassByName implements Comparator {

         public int compare(Object o1, Object o2) {

             Class<?> c1 = (Class)o1;

             Class<?> c2 = (Class)o2;

             return (c1.getName()).compareTo(c2.getName());

         }

     }

     /**

      * Comparator for ObjectStreamFields by name

      */

     private final static Comparator compareObjStrFieldsByName

         = new CompareObjStrFieldsByName();

     private static class CompareObjStrFieldsByName implements Comparator {

         public int compare(Object o1, Object o2) {

             ObjectStreamField osf1 = (ObjectStreamField)o1;

             ObjectStreamField osf2 = (ObjectStreamField)o2;

             return osf1.getName().compareTo(osf2.getName());

         }

     }

     /*

      * Comparator object for Members, Fields, and Methods

      */

     private static Comparator compareMemberByName =

         new CompareMemberByName();

     private static class CompareMemberByName implements Comparator {

         public int compare(Object o1, Object o2) {

             String s1 = ((Member)o1).getName();

             String s2 = ((Member)o2).getName();

             if (o1 instanceof Method) {

                 s1 += getSignature((Method)o1);

                 s2 += getSignature((Method)o2);

             } else if (o1 instanceof Constructor) {

                 s1 += getSignature((Constructor)o1);

                 s2 += getSignature((Constructor)o2);

             }

             return s1.compareTo(s2);

         }

     }

     /* It is expensive to recompute a method or constructor signature

        many times, so compute it only once using this data structure. */

     private static class MethodSignature implements Comparator {

         Member member;

         String signature;      // cached parameter signature

         /* Given an array of Method or Constructor members,

            return a sorted array of the non-private members.*/

         /* A better implementation would be to implement the returned data

            structure as an insertion sorted link list.*/

         static MethodSignature[] removePrivateAndSort(Member[] m) {

             int numNonPrivate = 0;

             for (int i = 0; i < m.length; i++) {

                 if (! Modifier.isPrivate(m[i].getModifiers())) {

                     numNonPrivate++;

                 }

             }

             MethodSignature[] cm = new MethodSignature[numNonPrivate];

             int cmi = 0;

             for (int i = 0; i < m.length; i++) {

                 if (! Modifier.isPrivate(m[i].getModifiers())) {

                     cm[cmi] = new MethodSignature(m[i]);

                     cmi++;

                 }

             }

             if (cmi > 0)

                 Arrays.sort(cm, cm[0]);

             return cm;

         }

         /* Assumes that o1 and o2 are either both methods

            or both constructors.*/

         public int compare(Object o1, Object o2) {

             /* Arrays.sort calls compare when o1 and o2 are equal.*/

             if (o1 == o2)

                 return 0;

             MethodSignature c1 = (MethodSignature)o1;

             MethodSignature c2 = (MethodSignature)o2;

             int result;

             if (isConstructor()) {

                 result = c1.signature.compareTo(c2.signature);

             } else { // is a Method.

                 result = c1.member.getName().compareTo(c2.member.getName());

                 if (result == 0)

                     result = c1.signature.compareTo(c2.signature);

             }

             return result;

         }

         final private boolean isConstructor() {

             return member instanceof Constructor;

         }

         private MethodSignature(Member m) {

             member = m;

             if (isConstructor()) {

                 signature = ObjectStreamClass.getSignature((Constructor)m);

             } else {

                 signature = ObjectStreamClass.getSignature((Method)m);

             }

         }

     }

     /**

      * Returns non-static, non-abstract method with given signature provided it

      * is defined by or accessible (via inheritance) by the given class, or

      * null if no match found.  Access checks are disabled on the returned

      * method (if any).

      *

      * Copied from the Merlin java.io.ObjectStreamClass.

      */

     private static Method getInheritableMethod(Class<?> cl, String name,

                                                Class<?>[] argTypes,

                                                Class<?> returnType)

     {

         Method meth = null;

         Class<?> defCl = cl;

         while (defCl != null) {

             try {

                 meth = defCl.getDeclaredMethod(name, argTypes);

                 break;

             } catch (NoSuchMethodException ex) {

                 defCl = defCl.getSuperclass();

             }

         }

         if ((meth == null) || (meth.getReturnType() != returnType)) {

             return null;

         }

         meth.setAccessible(true);

         int mods = meth.getModifiers();

         if ((mods & (Modifier.STATIC | Modifier.ABSTRACT)) != 0) {

             return null;

         } else if ((mods & (Modifier.PUBLIC | Modifier.PROTECTED)) != 0) {

             return meth;

         } else if ((mods & Modifier.PRIVATE) != 0) {

             return (cl == defCl) ? meth : null;

         } else {

             return packageEquals(cl, defCl) ? meth : null;

         }

     }

     /**

      * Returns true if classes are defined in the same package, false

      * otherwise.

      *

      * Copied from the Merlin java.io.ObjectStreamClass.

      */

     private static boolean packageEquals(Class<?> cl1, Class<?> cl2) {

         Package pkg1 = cl1.getPackage(), pkg2 = cl2.getPackage();

         return ((pkg1 == pkg2) || ((pkg1 != null) && (pkg1.equals(pkg2))));

     }

 }