ohair@286: /*
ohair@286:  * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
ohair@286:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ohair@286:  *
ohair@286:  * This code is free software; you can redistribute it and/or modify it
ohair@286:  * under the terms of the GNU General Public License version 2 only, as
ohair@286:  * published by the Free Software Foundation.  Oracle designates this
ohair@286:  * particular file as subject to the "Classpath" exception as provided
ohair@286:  * by Oracle in the LICENSE file that accompanied this code.
ohair@286:  *
ohair@286:  * This code is distributed in the hope that it will be useful, but WITHOUT
ohair@286:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ohair@286:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ohair@286:  * version 2 for more details (a copy is included in the LICENSE file that
ohair@286:  * accompanied this code).
ohair@286:  *
ohair@286:  * You should have received a copy of the GNU General Public License version
ohair@286:  * 2 along with this work; if not, write to the Free Software Foundation,
ohair@286:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ohair@286:  *
ohair@286:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@286:  * or visit www.oracle.com if you need additional information or have any
ohair@286:  * questions.
ohair@286:  */
ohair@286: 
ohair@286: package com.sun.xml.internal.bind.v2;
ohair@286: 
ohair@286: import java.lang.reflect.Constructor;
ohair@286: import java.lang.reflect.InvocationTargetException;
ohair@286: import java.lang.reflect.Method;
ohair@286: import java.lang.reflect.Modifier;
ohair@286: import java.lang.ref.WeakReference;
ohair@286: import java.util.Map;
ohair@286: import java.util.WeakHashMap;
ohair@286: import java.util.logging.Level;
ohair@286: import java.util.logging.Logger;
ohair@286: 
ohair@286: import com.sun.xml.internal.bind.Util;
ohair@286: 
ohair@286: /**
ohair@286:  * Creates new instances of classes.
ohair@286:  *
ohair@286:  * <p>
ohair@286:  * This code handles the case where the class is not public or the constructor is
ohair@286:  * not public.
ohair@286:  *
ohair@286:  * @since 2.0
ohair@286:  * @author Kohsuke Kawaguchi
ohair@286:  */
ohair@286: public final class ClassFactory {
ohair@286:     private static final Class[] emptyClass = new Class[0];
ohair@286:     private static final Object[] emptyObject = new Object[0];
ohair@286: 
ohair@286:     private static final Logger logger = Util.getClassLogger();
ohair@286: 
ohair@286:     /**
ohair@286:      * Cache from a class to its default constructor.
ohair@286:      *
ohair@286:      * To avoid synchronization among threads, we use {@link ThreadLocal}.
ohair@286:      */
ohair@286:     private static final ThreadLocal<Map<Class, WeakReference<Constructor>>> tls = new ThreadLocal<Map<Class,WeakReference<Constructor>>>() {
ohair@286:         @Override
ohair@286:         public Map<Class,WeakReference<Constructor>> initialValue() {
ohair@286:             return new WeakHashMap<Class,WeakReference<Constructor>>();
ohair@286:         }
ohair@286:     };
ohair@286: 
ohair@286:     public static void cleanCache() {
ohair@286:         if (tls != null) {
ohair@286:             try {
ohair@286:                 tls.remove();
ohair@286:             } catch (Exception e) {
ohair@286:                 logger.log(Level.WARNING, "Unable to clean Thread Local cache of classes used in Unmarshaller: {0}", e.getLocalizedMessage());
ohair@286:             }
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Creates a new instance of the class but throw exceptions without catching it.
ohair@286:      */
ohair@286:     public static <T> T create0( final Class<T> clazz ) throws IllegalAccessException, InvocationTargetException, InstantiationException {
ohair@286:         Map<Class,WeakReference<Constructor>> m = tls.get();
ohair@286:         Constructor<T> cons = null;
ohair@286:         WeakReference<Constructor> consRef = m.get(clazz);
ohair@286:         if(consRef!=null)
ohair@286:             cons = consRef.get();
ohair@286:         if(cons==null) {
ohair@286:             try {
ohair@286:                 cons = clazz.getDeclaredConstructor(emptyClass);
ohair@286:             } catch (NoSuchMethodException e) {
ohair@286:                 logger.log(Level.INFO,"No default constructor found on "+clazz,e);
ohair@286:                 NoSuchMethodError exp;
ohair@286:                 if(clazz.getDeclaringClass()!=null && !Modifier.isStatic(clazz.getModifiers())) {
ohair@286:                     exp = new NoSuchMethodError(Messages.NO_DEFAULT_CONSTRUCTOR_IN_INNER_CLASS.format(clazz.getName()));
ohair@286:                 } else {
ohair@286:                     exp = new NoSuchMethodError(e.getMessage());
ohair@286:                 }
ohair@286:                 exp.initCause(e);
ohair@286:                 throw exp;
ohair@286:             }
ohair@286: 
ohair@286:             int classMod = clazz.getModifiers();
ohair@286: 
ohair@286:             if(!Modifier.isPublic(classMod) || !Modifier.isPublic(cons.getModifiers())) {
ohair@286:                 // attempt to make it work even if the constructor is not accessible
ohair@286:                 try {
ohair@286:                     cons.setAccessible(true);
ohair@286:                 } catch(SecurityException e) {
ohair@286:                     // but if we don't have a permission to do so, work gracefully.
ohair@286:                     logger.log(Level.FINE,"Unable to make the constructor of "+clazz+" accessible",e);
ohair@286:                     throw e;
ohair@286:                 }
ohair@286:             }
ohair@286: 
ohair@286:             m.put(clazz,new WeakReference<Constructor>(cons));
ohair@286:         }
ohair@286: 
ohair@286:         return cons.newInstance(emptyObject);
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * The same as {@link #create0} but with an error handling to make
ohair@286:      * the instanciation error fatal.
ohair@286:      */
ohair@286:     public static <T> T create( Class<T> clazz ) {
ohair@286:         try {
ohair@286:             return create0(clazz);
ohair@286:         } catch (InstantiationException e) {
ohair@286:             logger.log(Level.INFO,"failed to create a new instance of "+clazz,e);
ohair@286:             throw new InstantiationError(e.toString());
ohair@286:         } catch (IllegalAccessException e) {
ohair@286:             logger.log(Level.INFO,"failed to create a new instance of "+clazz,e);
ohair@286:             throw new IllegalAccessError(e.toString());
ohair@286:         } catch (InvocationTargetException e) {
ohair@286:             Throwable target = e.getTargetException();
ohair@286: 
ohair@286:             // most likely an error on the user's code.
ohair@286:             // just let it through for the ease of debugging
ohair@286:             if(target instanceof RuntimeException)
ohair@286:                 throw (RuntimeException)target;
ohair@286: 
ohair@286:             // error. just forward it for the ease of debugging
ohair@286:             if(target instanceof Error)
ohair@286:                 throw (Error)target;
ohair@286: 
ohair@286:             // a checked exception.
ohair@286:             // not sure how we should report this error,
ohair@286:             // but for now we just forward it by wrapping it into a runtime exception
ohair@286:             throw new IllegalStateException(target);
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      *  Call a method in the factory class to get the object.
ohair@286:      */
ohair@286:     public static Object create(Method method) {
ohair@286:         Throwable errorMsg;
ohair@286:         try {
ohair@286:             return method.invoke(null, emptyObject);
ohair@286:         } catch (InvocationTargetException ive) {
ohair@286:             Throwable target = ive.getTargetException();
ohair@286: 
ohair@286:             if(target instanceof RuntimeException)
ohair@286:                 throw (RuntimeException)target;
ohair@286: 
ohair@286:             if(target instanceof Error)
ohair@286:                 throw (Error)target;
ohair@286: 
ohair@286:             throw new IllegalStateException(target);
ohair@286:         } catch (IllegalAccessException e) {
ohair@286:             logger.log(Level.INFO,"failed to create a new instance of "+method.getReturnType().getName(),e);
ohair@286:             throw new IllegalAccessError(e.toString());
ohair@286:         } catch (IllegalArgumentException iae){
ohair@286:             logger.log(Level.INFO,"failed to create a new instance of "+method.getReturnType().getName(),iae);
ohair@286:             errorMsg = iae;
ohair@286:         } catch (NullPointerException npe){
ohair@286:             logger.log(Level.INFO,"failed to create a new instance of "+method.getReturnType().getName(),npe);
ohair@286:             errorMsg = npe;
ohair@286:         } catch (ExceptionInInitializerError eie){
ohair@286:             logger.log(Level.INFO,"failed to create a new instance of "+method.getReturnType().getName(),eie);
ohair@286:             errorMsg = eie;
ohair@286:         }
ohair@286: 
ohair@286:         NoSuchMethodError exp;
ohair@286:         exp = new NoSuchMethodError(errorMsg.getMessage());
ohair@286:         exp.initCause(errorMsg);
ohair@286:         throw exp;
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Infers the instanciable implementation class that can be assigned to the given field type.
ohair@286:      *
ohair@286:      * @return null
ohair@286:      *      if inference fails.
ohair@286:      */
ohair@286:     public static <T> Class<? extends T> inferImplClass(Class<T> fieldType, Class[] knownImplClasses) {
ohair@286:         if(!fieldType.isInterface())
ohair@286:             return fieldType;
ohair@286: 
ohair@286:         for( Class<?> impl : knownImplClasses ) {
ohair@286:             if(fieldType.isAssignableFrom(impl))
ohair@286:                 return impl.asSubclass(fieldType);
ohair@286:         }
ohair@286: 
ohair@286:         // if we can't find an implementation class,
ohair@286:         // let's just hope that we will never need to create a new object,
ohair@286:         // and returns null
ohair@286:         return null;
ohair@286:     }
ohair@286: }