/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* License: GNU Lesser General Public License (LGPL), version 2.1 or later.
* See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
*/
package org.hibernate.bytecode.internal.javassist;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.security.ProtectionDomain;
import javassist.CannotCompileException;
import javassist.bytecode.AccessFlag;
import javassist.bytecode.Bytecode;
import javassist.bytecode.ClassFile;
import javassist.bytecode.CodeAttribute;
import javassist.bytecode.ConstPool;
import javassist.bytecode.MethodInfo;
import javassist.bytecode.Opcode;
import javassist.bytecode.StackMapTable;
import javassist.util.proxy.FactoryHelper;
import javassist.util.proxy.RuntimeSupport;
/**
* A factory of bulk accessors.
*
* @author Muga Nishizawa
* @author modified by Shigeru Chiba
*/
class BulkAccessorFactory {
private static final String PACKAGE_NAME_PREFIX = "org.javassist.tmp.";
private static final String BULKACESSOR_CLASS_NAME = BulkAccessor.class.getName();
private static final String OBJECT_CLASS_NAME = Object.class.getName();
private static final String GENERATED_GETTER_NAME = "getPropertyValues";
private static final String GENERATED_SETTER_NAME = "setPropertyValues";
private static final String GET_SETTER_DESC = "(Ljava/lang/Object;[Ljava/lang/Object;)V";
private static final String THROWABLE_CLASS_NAME = Throwable.class.getName();
private static final String BULKEXCEPTION_CLASS_NAME = BulkAccessorException.class.getName();
private static int counter;
private Class targetBean;
private String[] getterNames;
private String[] setterNames;
private Class[] types;
public String writeDirectory;
BulkAccessorFactory(
Class target,
String[] getterNames,
String[] setterNames,
Class[] types) {
this.targetBean = target;
this.getterNames = getterNames;
this.setterNames = setterNames;
this.types = types;
this.writeDirectory = null;
}
BulkAccessor create() {
final Method[] getters = new Method[getterNames.length];
final Method[] setters = new Method[setterNames.length];
findAccessors( targetBean, getterNames, setterNames, types, getters, setters );
final Class beanClass;
try {
final ClassFile classfile = make( getters, setters );
final ClassLoader loader = this.getClassLoader();
if ( writeDirectory != null ) {
FactoryHelper.writeFile( classfile, writeDirectory );
}
beanClass = FactoryHelper.toClass( classfile, loader, getDomain() );
return (BulkAccessor) this.newInstance( beanClass );
}
catch ( Exception e ) {
throw new BulkAccessorException( e.getMessage(), e );
}
}
private ProtectionDomain getDomain() {
final Class cl;
if ( this.targetBean != null ) {
cl = this.targetBean;
}
else {
cl = this.getClass();
}
return cl.getProtectionDomain();
}
private ClassFile make(Method[] getters, Method[] setters) throws CannotCompileException {
String className = targetBean.getName();
// set the name of bulk accessor.
className = className + "_$$_bulkaccess_" + counter++;
if ( className.startsWith( "java." ) ) {
className = PACKAGE_NAME_PREFIX + className;
}
final ClassFile classfile = new ClassFile( false, className, BULKACESSOR_CLASS_NAME );
classfile.setAccessFlags( AccessFlag.PUBLIC );
addDefaultConstructor( classfile );
addGetter( classfile, getters );
addSetter( classfile, setters );
return classfile;
}
private ClassLoader getClassLoader() {
if ( targetBean != null && targetBean.getName().equals( OBJECT_CLASS_NAME ) ) {
return targetBean.getClassLoader();
}
else {
return getClass().getClassLoader();
}
}
private Object newInstance(Class type) throws Exception {
final BulkAccessor instance = (BulkAccessor) type.newInstance();
instance.target = targetBean;
final int len = getterNames.length;
instance.getters = new String[len];
instance.setters = new String[len];
instance.types = new Class[len];
for ( int i = 0; i < len; i++ ) {
instance.getters[i] = getterNames[i];
instance.setters[i] = setterNames[i];
instance.types[i] = types[i];
}
return instance;
}
/**
* Declares a constructor that takes no parameter.
*
* @param classfile The class descriptor
*
* @throws CannotCompileException Indicates trouble with the underlying Javassist calls
*/
private void addDefaultConstructor(ClassFile classfile) throws CannotCompileException {
final ConstPool constPool = classfile.getConstPool();
final String constructorSignature = "()V";
final MethodInfo constructorMethodInfo = new MethodInfo( constPool, MethodInfo.nameInit, constructorSignature );
final Bytecode code = new Bytecode( constPool, 0, 1 );
// aload_0
code.addAload( 0 );
// invokespecial
code.addInvokespecial( BulkAccessor.class.getName(), MethodInfo.nameInit, constructorSignature );
// return
code.addOpcode( Opcode.RETURN );
constructorMethodInfo.setCodeAttribute( code.toCodeAttribute() );
constructorMethodInfo.setAccessFlags( AccessFlag.PUBLIC );
classfile.addMethod( constructorMethodInfo );
}
private void addGetter(ClassFile classfile, final Method[] getters) throws CannotCompileException {
final ConstPool constPool = classfile.getConstPool();
final int targetBeanConstPoolIndex = constPool.addClassInfo( this.targetBean.getName() );
final String desc = GET_SETTER_DESC;
final MethodInfo getterMethodInfo = new MethodInfo( constPool, GENERATED_GETTER_NAME, desc );
final Bytecode code = new Bytecode( constPool, 6, 4 );
/* | this | bean | args | raw bean | */
if ( getters.length >= 0 ) {
// aload_1 // load bean
code.addAload( 1 );
// checkcast // cast bean
code.addCheckcast( this.targetBean.getName() );
// astore_3 // store bean
code.addAstore( 3 );
for ( int i = 0; i < getters.length; ++i ) {
if ( getters[i] != null ) {
final Method getter = getters[i];
// aload_2 // args
code.addAload( 2 );
// iconst_i // continue to aastore
// growing stack is 1
code.addIconst( i );
final Class returnType = getter.getReturnType();
int typeIndex = -1;
if ( returnType.isPrimitive() ) {
typeIndex = FactoryHelper.typeIndex( returnType );
// new
code.addNew( FactoryHelper.wrapperTypes[typeIndex] );
// dup
code.addOpcode( Opcode.DUP );
}
// aload_3 // load the raw bean
code.addAload( 3 );
final String getterSignature = RuntimeSupport.makeDescriptor( getter );
final String getterName = getter.getName();
if ( this.targetBean.isInterface() ) {
// invokeinterface
code.addInvokeinterface( targetBeanConstPoolIndex, getterName, getterSignature, 1 );
}
else {
// invokevirtual
code.addInvokevirtual( targetBeanConstPoolIndex, getterName, getterSignature );
}
if ( typeIndex >= 0 ) {
// is a primitive type
// invokespecial
code.addInvokespecial(
FactoryHelper.wrapperTypes[typeIndex],
MethodInfo.nameInit,
FactoryHelper.wrapperDesc[typeIndex]
);
}
// aastore // args
code.add( Opcode.AASTORE );
code.growStack( -3 );
}
}
}
// return
code.addOpcode( Opcode.RETURN );
getterMethodInfo.setCodeAttribute( code.toCodeAttribute() );
getterMethodInfo.setAccessFlags( AccessFlag.PUBLIC );
classfile.addMethod( getterMethodInfo );
}
private void addSetter(ClassFile classfile, final Method[] setters) throws CannotCompileException {
final ConstPool constPool = classfile.getConstPool();
final int targetTypeConstPoolIndex = constPool.addClassInfo( this.targetBean.getName() );
final String desc = GET_SETTER_DESC;
final MethodInfo setterMethodInfo = new MethodInfo( constPool, GENERATED_SETTER_NAME, desc );
final Bytecode code = new Bytecode( constPool, 4, 6 );
StackMapTable stackmap = null;
/* | this | bean | args | i | raw bean | exception | */
if ( setters.length > 0 ) {
// required to exception table
int start;
int end;
// iconst_0 // i
code.addIconst( 0 );
// istore_3 // store i
code.addIstore( 3 );
// aload_1 // load the bean
code.addAload( 1 );
// checkcast // cast the bean into a raw bean
code.addCheckcast( this.targetBean.getName() );
// astore 4 // store the raw bean
code.addAstore( 4 );
/* current stack len = 0 */
// start region to handling exception (BulkAccessorException)
start = code.currentPc();
int lastIndex = 0;
for ( int i = 0; i < setters.length; ++i ) {
if ( setters[i] != null ) {
final int diff = i - lastIndex;
if ( diff > 0 ) {
// iinc 3, 1
code.addOpcode( Opcode.IINC );
code.add( 3 );
code.add( diff );
lastIndex = i;
}
}
/* current stack len = 0 */
// aload 4 // load the raw bean
code.addAload( 4 );
// aload_2 // load the args
code.addAload( 2 );
// iconst_i
code.addIconst( i );
// aaload
code.addOpcode( Opcode.AALOAD );
// checkcast
final Class[] setterParamTypes = setters[i].getParameterTypes();
final Class setterParamType = setterParamTypes[0];
if ( setterParamType.isPrimitive() ) {
// checkcast (case of primitive type)
// invokevirtual (case of primitive type)
this.addUnwrapper( code, setterParamType );
}
else {
// checkcast (case of reference type)
code.addCheckcast( setterParamType.getName() );
}
/* current stack len = 2 */
final String rawSetterMethodDesc = RuntimeSupport.makeDescriptor( setters[i] );
if ( !this.targetBean.isInterface() ) {
// invokevirtual
code.addInvokevirtual( targetTypeConstPoolIndex, setters[i].getName(), rawSetterMethodDesc );
}
else {
// invokeinterface
final Class[] params = setters[i].getParameterTypes();
int size;
if ( params[0].equals( Double.TYPE ) || params[0].equals( Long.TYPE ) ) {
size = 3;
}
else {
size = 2;
}
code.addInvokeinterface( targetTypeConstPoolIndex, setters[i].getName(), rawSetterMethodDesc, size );
}
}
// end region to handling exception (BulkAccessorException)
end = code.currentPc();
// return
code.addOpcode( Opcode.RETURN );
/* current stack len = 0 */
// register in exception table
final int throwableTypeIndex = constPool.addClassInfo( THROWABLE_CLASS_NAME );
final int handlerPc = code.currentPc();
code.addExceptionHandler( start, end, handlerPc, throwableTypeIndex );
// astore 5 // store exception
code.addAstore( 5 );
// new // BulkAccessorException
code.addNew( BULKEXCEPTION_CLASS_NAME );
// dup
code.addOpcode( Opcode.DUP );
// aload 5 // load exception
code.addAload( 5 );
// iload_3 // i
code.addIload( 3 );
// invokespecial // BulkAccessorException.<init>
final String consDesc = "(Ljava/lang/Throwable;I)V";
code.addInvokespecial( BULKEXCEPTION_CLASS_NAME, MethodInfo.nameInit, consDesc );
// athrow
code.addOpcode( Opcode.ATHROW );
final StackMapTable.Writer writer = new StackMapTable.Writer(32);
final int[] localTags = {
StackMapTable.OBJECT,
StackMapTable.OBJECT,
StackMapTable.OBJECT,
StackMapTable.INTEGER
};
final int[] localData = {
constPool.getThisClassInfo(),
constPool.addClassInfo( "java/lang/Object" ),
constPool.addClassInfo( "[Ljava/lang/Object;" ),
0
};
final int[] stackTags = {
StackMapTable.OBJECT
};
final int[] stackData = {
throwableTypeIndex
};
writer.fullFrame( handlerPc, localTags, localData, stackTags, stackData );
stackmap = writer.toStackMapTable( constPool );
}
else {
// return
code.addOpcode( Opcode.RETURN );
}
final CodeAttribute ca = code.toCodeAttribute();
if ( stackmap != null ) {
ca.setAttribute( stackmap );
}
setterMethodInfo.setCodeAttribute( ca );
setterMethodInfo.setAccessFlags( AccessFlag.PUBLIC );
classfile.addMethod( setterMethodInfo );
}
private void addUnwrapper(Bytecode code, Class type) {
final int index = FactoryHelper.typeIndex( type );
final String wrapperType = FactoryHelper.wrapperTypes[index];
// checkcast
code.addCheckcast( wrapperType );
// invokevirtual
code.addInvokevirtual( wrapperType, FactoryHelper.unwarpMethods[index], FactoryHelper.unwrapDesc[index] );
}
private static void findAccessors(
Class clazz,
String[] getterNames,
String[] setterNames,
Class[] types,
Method[] getters,
Method[] setters) {
final int length = types.length;
if ( setterNames.length != length || getterNames.length != length ) {
throw new BulkAccessorException( "bad number of accessors" );
}
final Class[] getParam = new Class[0];
final Class[] setParam = new Class[1];
for ( int i = 0; i < length; i++ ) {
if ( getterNames[i] != null ) {
final Method getter = findAccessor( clazz, getterNames[i], getParam, i );
if ( getter.getReturnType() != types[i] ) {
throw new BulkAccessorException( "wrong return type: " + getterNames[i], i );
}
getters[i] = getter;
}
if ( setterNames[i] != null ) {
setParam[0] = types[i];
setters[i] = findAccessor( clazz, setterNames[i], setParam, i );
}
}
}
@SuppressWarnings("unchecked")
private static Method findAccessor(Class clazz, String name, Class[] params, int index)
throws BulkAccessorException {
try {
final Method method = clazz.getDeclaredMethod( name, params );
if ( Modifier.isPrivate( method.getModifiers() ) ) {
throw new BulkAccessorException( "private property", index );
}
return method;
}
catch ( NoSuchMethodException e ) {
throw new BulkAccessorException( "cannot find an accessor", index );
}
}
}