/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.openejb.core.cmp.cmp2;
import org.apache.xbean.asm5.ClassWriter;
import org.apache.xbean.asm5.FieldVisitor;
import org.apache.xbean.asm5.MethodVisitor;
import org.apache.xbean.asm5.Opcodes;
import org.apache.xbean.asm5.Type;
/**
* Class for generating a class file that implements
* CMP1 type of persistence.
*/
public class Cmp1Generator implements Opcodes {
private String implClassName;
private String beanClassName;
private ClassWriter cw;
private boolean unknownPk;
private final PostCreateGenerator postCreateGenerator;
/**
* Constructor for a CMP1 class generator.
*
* @param cmpImplClass The name of the generated implementation class.
* @param beanClass The source Bean class we're wrappering.
*/
public Cmp1Generator(final String cmpImplClass, final Class beanClass) {
beanClassName = Type.getInternalName(beanClass);
implClassName = cmpImplClass.replace('.', '/');
cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES);
postCreateGenerator = new PostCreateGenerator(beanClass, cw);
}
/**
* Generate the class for implementing CMP 1 level of
* persistence.
*
* @return The generated byte-array containing the class data.
*/
public byte[] generate() {
// We're creating a superclass for the implementation. We force this to implement
// EntityBean to allow POJOs to be used as the bean class.
cw.visit(V1_5, ACC_PUBLIC + ACC_SUPER, implClassName, null, beanClassName, new String[]{"javax/ejb/EntityBean"});
// if we have an unknown pk, we need to add a field for the pk
if (unknownPk) {
// public Long OpenEJB_pk;
final FieldVisitor fv = cw.visitField(ACC_PUBLIC, "OpenEJB_pk", "Ljava/lang/Long;", null, null);
fv.visitEnd();
}
// there's not much to generate here. We create a default constructor, then generate the
// post create methods. A lot of the work is done by having mapped superclass information that
// we pass to the JPA engine.
createConstructor();
postCreateGenerator.generate();
cw.visitEnd();
return cw.toByteArray();
}
/**
* Create a default constructor for our bean super
* class. This is just a forwarding constructor that
* calls the superclass (the bean implementation class)
* default constructor.
*/
private void createConstructor() {
MethodVisitor mv = mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
mv.visitCode();
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(INVOKESPECIAL, beanClassName, "<init>", "()V", false);
mv.visitInsn(RETURN);
mv.visitMaxs(0, 0);
mv.visitEnd();
}
public boolean isUnknownPk() {
return unknownPk;
}
public void setUnknownPk(final boolean unknownPk) {
this.unknownPk = unknownPk;
}
}