/***
* ASM Guide
* Copyright (c) 2007 Eric Bruneton
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
package ch6.sec1;
import static org.objectweb.asm.Opcodes.ACC_PRIVATE;
import static org.objectweb.asm.Opcodes.ACC_PUBLIC;
import static org.objectweb.asm.Opcodes.ALOAD;
import static org.objectweb.asm.Opcodes.ATHROW;
import static org.objectweb.asm.Opcodes.DUP;
import static org.objectweb.asm.Opcodes.F_SAME;
import static org.objectweb.asm.Opcodes.GETFIELD;
import static org.objectweb.asm.Opcodes.GOTO;
import static org.objectweb.asm.Opcodes.IFLT;
import static org.objectweb.asm.Opcodes.ILOAD;
import static org.objectweb.asm.Opcodes.INVOKESPECIAL;
import static org.objectweb.asm.Opcodes.IRETURN;
import static org.objectweb.asm.Opcodes.NEW;
import static org.objectweb.asm.Opcodes.PUTFIELD;
import static org.objectweb.asm.Opcodes.RETURN;
import static org.objectweb.asm.Opcodes.V1_6;
import java.io.PrintWriter;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.FieldInsnNode;
import org.objectweb.asm.tree.FieldNode;
import org.objectweb.asm.tree.FrameNode;
import org.objectweb.asm.tree.InsnList;
import org.objectweb.asm.tree.InsnNode;
import org.objectweb.asm.tree.JumpInsnNode;
import org.objectweb.asm.tree.LabelNode;
import org.objectweb.asm.tree.MethodInsnNode;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.TypeInsnNode;
import org.objectweb.asm.tree.VarInsnNode;
/**
* ASM Guide example class.
*
* @author Eric Bruneton
*/
public class BeanGenerator {
public byte[] generate(PrintWriter printWriter) {
ClassNode cn = new ClassNode();
cn.version = V1_6;
cn.access = ACC_PUBLIC;
cn.name = "pkg/Bean";
cn.superName = "java/lang/Object";
cn.sourceDebug = "Bean.java";
cn.fields.add(new FieldNode(ACC_PRIVATE, "f", "I", null, null));
{
MethodNode mn = new MethodNode(ACC_PUBLIC, "<init>", "()V", null,
null);
cn.methods.add(mn);
InsnList il = mn.instructions;
il.add(new VarInsnNode(ALOAD, 0));
il.add(new MethodInsnNode(INVOKESPECIAL, "java/lang/Object",
"<init>", "()V"));
il.add(new InsnNode(RETURN));
mn.maxStack = 1;
mn.maxLocals = 1;
}
{
MethodNode mn = new MethodNode(ACC_PUBLIC, "getF", "()I", null,
null);
cn.methods.add(mn);
InsnList il = mn.instructions;
il.add(new VarInsnNode(ALOAD, 0));
il.add(new FieldInsnNode(GETFIELD, "pkg/Bean", "f", "I"));
il.add(new InsnNode(IRETURN));
mn.maxStack = 1;
mn.maxLocals = 1;
}
{
MethodNode mn = new MethodNode(ACC_PUBLIC, "setF", "(I)V", null,
null);
cn.methods.add(mn);
InsnList il = mn.instructions;
il.add(new VarInsnNode(ALOAD, 0));
il.add(new VarInsnNode(ILOAD, 1));
il.add(new FieldInsnNode(PUTFIELD, "pkg/Bean", "f", "I"));
il.add(new InsnNode(RETURN));
mn.maxStack = 2;
mn.maxLocals = 2;
}
MethodNode mn = new MethodNode(ACC_PUBLIC, "checkAndSetF", "(I)V",
null, null);
cn.methods.add(mn);
InsnList il = mn.instructions;
il.add(new VarInsnNode(ILOAD, 1));
LabelNode label = new LabelNode();
il.add(new JumpInsnNode(IFLT, label));
il.add(new VarInsnNode(ALOAD, 0));
il.add(new VarInsnNode(ILOAD, 1));
il.add(new FieldInsnNode(PUTFIELD, "pkg/Bean", "f", "I"));
LabelNode end = new LabelNode();
il.add(new JumpInsnNode(GOTO, end));
il.add(label);
il.add(new FrameNode(F_SAME, 0, null, 0, null));
il.add(new TypeInsnNode(NEW, "java/lang/IllegalArgumentException"));
il.add(new InsnNode(DUP));
il.add(new MethodInsnNode(INVOKESPECIAL,
"java/lang/IllegalArgumentException", "<init>", "()V"));
il.add(new InsnNode(ATHROW));
il.add(end);
il.add(new FrameNode(F_SAME, 0, null, 0, null));
il.add(new InsnNode(RETURN));
mn.maxStack = 2;
mn.maxLocals = 2;
ClassWriter cw = new ClassWriter(0);
cn.accept(cw);
return cw.toByteArray();
}
}