Java Bytecode.addInvokespecial方法代码示例

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
/**
 * 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 );
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
/**
 * Declares a constructor that takes no parameter.
 *
 * @param classfile
 * @throws CannotCompileException
 */
private void addDefaultConstructor(ClassFile classfile) throws CannotCompileException {
	ConstPool cp = classfile.getConstPool();
	String cons_desc = "()V";
	MethodInfo mi = new MethodInfo( cp, MethodInfo.nameInit, cons_desc );

	Bytecode code = new Bytecode( cp, 0, 1 );
	// aload_0
	code.addAload( 0 );
	// invokespecial
	code.addInvokespecial( BulkAccessor.class.getName(), MethodInfo.nameInit, cons_desc );
	// return
	code.addOpcode( Opcode.RETURN );

	mi.setCodeAttribute( code.toCodeAttribute() );
	mi.setAccessFlags( AccessFlag.PUBLIC );
	classfile.addMethod( mi );
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
private void addGetter(ClassFile classfile, final Method[] getters) throws CannotCompileException {
	ConstPool cp = classfile.getConstPool();
	int target_type_index = cp.addClassInfo( this.targetBean.getName() );
	String desc = GET_SETTER_DESC;
	MethodInfo mi = new MethodInfo( cp, GENERATED_GETTER_NAME, desc );

	Bytecode code = new Bytecode( cp, 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 ) {
				Method getter = getters[i];
				// aload_2 // args
				code.addAload( 2 );
				// iconst_i // continue to aastore
				code.addIconst( i ); // growing stack is 1
				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 );
				String getter_desc = RuntimeSupport.makeDescriptor( getter );
				String getterName = getter.getName();
				if ( this.targetBean.isInterface() ) {
					// invokeinterface
					code.addInvokeinterface( target_type_index, getterName, getter_desc, 1 );
				}
				else {
					// invokevirtual
					code.addInvokevirtual( target_type_index, getterName, getter_desc );
				}

				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 );

	mi.setCodeAttribute( code.toCodeAttribute() );
	mi.setAccessFlags( AccessFlag.PUBLIC );
	classfile.addMethod( mi );
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
/**
 * Replaces creation of the array with the creation of the <em>KoratArray</em>
 * field. Just invokes its constructor with the <code>int</code> parameter
 * that represents the length of the array.
 * 
 * @param arrayType - 
 *            type of array in terms of JVM
 * @param cit -
 *            iterator through method's body code
 * @param idx -
 *            current position in the <code>cit</code>
 * @throws BadBytecode
 */
private void delegateNewArray(int arrayType, CodeIterator cit, int idx) {

    // check how this new array is going to be consumed
    if (operandStack.peek().consumedBy != ConsumedByKind.PUTFIELD)
        return;
    
    String koratClassName = koratArrayClassNames[arrayType];
    int locals = cit.get().getMaxLocals();
    int localVar1 = locals + 1;

    try {

        Bytecode codes = new Bytecode(constPool);
        codes.addIstore(localVar1);
        codes.addNew(koratClassName);
        codes.addOpcode(Opcode.DUP);
        codes.addIload(localVar1);
        String descr = Descriptor.ofMethod(CtClass.voidType,
                new CtClass[] { CtClass.intType });
        codes.addInvokespecial(koratClassName, "<init>", descr);

        int diff = codes.getSize() - 2;
        // -2 because original instruction
        // (NEWARRAY) is 2 bytes long.

        cit.insertGap(idx, diff);
        cit.write(codes.get(), idx);
        cit.get().setMaxLocals(localVar1 + 1);

    } catch (BadBytecode e) {
        throw new RuntimeException(e);
    }

}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
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 );
}