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