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Glassfish example source code file (AsmSerializableBeanGenerator.java)

This example Glassfish source code file (AsmSerializableBeanGenerator.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Glassfish tags/keywords

asmserializablebeangenerator, class, class, classloader, classwriter, constructor, could, could, exception, exception, io, methodvisitor, reflection, runtimeexception, security, string, string

The Glassfish AsmSerializableBeanGenerator.java source code

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package com.sun.ejb.codegen;

import org.objectweb.asm.*;
import org.objectweb.asm.commons.GeneratorAdapter;
import org.objectweb.asm.commons.Method;

import java.lang.reflect.Constructor;

import java.io.Serializable;

import com.sun.enterprise.deployment.util.TypeUtil;

import java.security.ProtectionDomain ;
import java.security.PrivilegedAction ;
import java.security.AccessController ;
import java.security.Permission ;
import java.lang.reflect.ReflectPermission ;

public class AsmSerializableBeanGenerator
    implements Opcodes {

    private static final int INTF_FLAGS = ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES;

    private byte[] classData = null;

    private Class loadedClass = null;
            ;
    private ClassLoader loader;


    private Class baseClass;

    private String subclassName;


    private static final boolean _debug = Boolean.valueOf(System.getProperty("emit.ejb.optional.interface"));

    public AsmSerializableBeanGenerator(ClassLoader loader, Class baseClass, String serializableSubclassName) {
        this.loader = loader;
        this.baseClass = baseClass;
        subclassName = serializableSubclassName;
    }

    public String getSerializableSubclassName() {

        return subclassName;

    }
    
    public Class generateSerializableSubclass()
        throws Exception {

        try {
            loadedClass = loader.loadClass(subclassName);
            return loadedClass;
        } catch(ClassNotFoundException e) {
            // Not loaded yet.  Just continue
        }

        ClassWriter cw = new ClassWriter(INTF_FLAGS);

        //ClassVisitor tv = //(_debug)
                //new TraceClassVisitor(cw, new PrintWriter(System.out));
        ClassVisitor tv = cw;
        String subclassInternalName = subclassName.replace('.', '/');

        String[] interfaces = new String[] {
             Type.getType(Serializable.class).getInternalName()
        };

        tv.visit(V1_1, ACC_PUBLIC,
                subclassInternalName, null,
                Type.getType(baseClass).getInternalName(), interfaces);


	// Generate constructor. The EJB spec only allows no-arg constructors, but
	// JSR 299 added requirements that allow a single constructor to define
	// parameters injected by CDI.
	
	Constructor[] ctors = baseClass.getConstructors();
	Constructor ctorWithParams = null;
	for(Constructor ctor : ctors) {
	    if( ctor.getParameterTypes().length > 0 ) {
		ctorWithParams = ctor;
		break;
	    }
	}

	int numArgsToPass = 1; // default is 1 to just handle 'this'
	String paramTypeString = "()V";

	if( ctorWithParams != null ) {
	    Class[] paramTypes = ctorWithParams.getParameterTypes();	    
	    numArgsToPass = paramTypes.length + 1;
	    paramTypeString = Type.getConstructorDescriptor(ctorWithParams);
	}

	MethodVisitor ctorv = tv.visitMethod(ACC_PUBLIC, "<init>", paramTypeString, null, null);

	for(int i = 0; i < numArgsToPass; i++) {
	    ctorv.visitVarInsn(ALOAD, i);
	}

	ctorv.visitMethodInsn(INVOKESPECIAL,  Type.getType(baseClass).getInternalName(), "<init>",
			   paramTypeString);
	ctorv.visitInsn(RETURN);
	ctorv.visitMaxs(numArgsToPass, numArgsToPass);

        MethodVisitor cv = cw.visitMethod(ACC_PRIVATE, "writeObject", "(Ljava/io/ObjectOutputStream;)V", null, new String[] { "java/io/IOException" });
        cv.visitVarInsn(ALOAD, 0);
        cv.visitVarInsn(ALOAD, 1);
        cv.visitMethodInsn(INVOKESTATIC, "com/sun/ejb/EJBUtils", "serializeObjectFields", "(Ljava/lang/Object;Ljava/io/ObjectOutputStream;)V");
        cv.visitInsn(RETURN);
        cv.visitMaxs(2, 2);


        cv = cw.visitMethod(ACC_PRIVATE, "readObject", "(Ljava/io/ObjectInputStream;)V", null, new String[] { "java/io/IOException", "java/lang/ClassNotFoundException" });
        cv.visitVarInsn(ALOAD, 0);
        cv.visitVarInsn(ALOAD, 1);
        cv.visitMethodInsn(INVOKESTATIC, "com/sun/ejb/EJBUtils", "deserializeObjectFields", "(Ljava/lang/Object;Ljava/io/ObjectInputStream;)V");
        cv.visitInsn(RETURN);
        cv.visitMaxs(2, 2);

        
        /**
        Type[] eTypes = new Type[] { Type.getType(java.io.IOException.class)};

        Method writeObjMethod = Method.getMethod("void writeObject (java.io.ObjectOutputStream)");
        GeneratorAdapter writeObjMethodAdapter =
                new GeneratorAdapter(ACC_PRIVATE, writeObjMethod, null, eTypes, tv);

        Type ejbUtilsType = Type.getType(com.sun.ejb.EJBUtils.class);
        Method ejbUtilsWrite = Method.getMethod
                ("void serializeObjectFields (java.lang.Class, java.lang.Object, java.lang.Object)");


        writeObjMethodAdapter.push(Type.getType(ejbClass));
        writeObjMethodAdapter.loadThis();
        writeObjMethodAdapter.loadArg(0);

        writeObjMethodAdapter.invokeStatic( ejbUtilsType, ejbUtilsWrite);

        writeObjMethodAdapter.endMethod();


        //
        eTypes = new Type[] { Type.getType(java.io.IOException.class),
                              Type.getType(java.lang.ClassNotFoundException.class)};

        Method readObjMethod = Method.getMethod("void readObject (java.io.ObjectInputStream)");
        GeneratorAdapter readObjMethodAdapter =
                new GeneratorAdapter(ACC_PRIVATE, readObjMethod, null, eTypes, tv);


        Method ejbUtilsRead = Method.getMethod
                ("void deserializeObjectFields (java.lang.Class, java.lang.Object, java.lang.Object)");


        readObjMethodAdapter.push(Type.getType(ejbClass));
        readObjMethodAdapter.loadThis();
        readObjMethodAdapter.loadArg(0);

        readObjMethodAdapter.invokeStatic( ejbUtilsType, ejbUtilsRead);

        readObjMethodAdapter.endMethod();

        **/



        tv.visitEnd();

        classData = cw.toByteArray();

        loadedClass = (Class) java.security.AccessController.doPrivileged(
                        new java.security.PrivilegedAction() {
                            public java.lang.Object run() {
                                return makeClass(subclassName, classData, baseClass.getProtectionDomain(), loader);
                            }
                        }
                );

        return loadedClass;


    }

      // Name that Java uses for constructor methods
    private static final String CONSTRUCTOR_METHOD_NAME = "<init>" ;

    // Name that Java uses for a classes static initializer method
    private static final String STATIC_INITIALIZER_METHOD_NAME = "<clinit>" ;
    
     // A Method for the protected ClassLoader.defineClass method, which we access
    // using reflection.  This requires the supressAccessChecks permission.
    private static final java.lang.reflect.Method defineClassMethod = AccessController.doPrivileged(
	new PrivilegedAction<java.lang.reflect.Method>() {
	    public java.lang.reflect.Method run() {
		try {
		    java.lang.reflect.Method meth = ClassLoader.class.getDeclaredMethod(
			"defineClass", String.class,
			byte[].class, int.class, int.class,
			ProtectionDomain.class ) ;
		    meth.setAccessible( true ) ;
		    return meth ;
		} catch (Exception exc) {
		    throw new RuntimeException(
			"Could not find defineClass method!", exc ) ;
		}
	    }
	}
    ) ;

    private static final Permission accessControlPermission =
	    new ReflectPermission( "suppressAccessChecks" ) ;

    // This requires a permission check
    private Class<?> makeClass( String name, byte[] def, ProtectionDomain pd,
	    ClassLoader loader ) {

	SecurityManager sman = System.getSecurityManager() ;
	if (sman != null)
	    sman.checkPermission( accessControlPermission ) ;

	try {
	    return (Class)defineClassMethod.invoke( loader,
		name, def, 0, def.length, pd ) ;
	} catch (Exception exc) {
	    throw new RuntimeException( "Could not invoke defineClass!",
		exc ) ;
	}
    }


}

Other Glassfish examples (source code examples)

Here is a short list of links related to this Glassfish AsmSerializableBeanGenerator.java source code file:

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