/***
* 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.
*/
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.GETFIELD;
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.PUTFIELD;
import static org.objectweb.asm.Opcodes.RETURN;
import static org.objectweb.asm.Opcodes.V1_1;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Type;
import org.objectweb.asm.util.CheckClassAdapter;
/**
* ASM Guide example class.
*
* @author Eric Bruneton
*/
public class BeanGenerator3 extends ClassLoader {
private String name;
private Map<String, Type> fields;
public BeanGenerator3(String name, Map<String, Type> fields) {
this.name = name;
this.fields = fields;
}
public void generate(ClassVisitor cv) {
MethodVisitor mv;
cv.visit(V1_1, ACC_PUBLIC, name, null, "java/lang/Object", null);
// generate default constructor
mv = cv.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
if (mv != null) {
mv.visitCode();
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
mv.visitInsn(RETURN);
mv.visitMaxs(1, 1);
mv.visitEnd();
}
Iterator<Map.Entry<String, Type>> i = fields.entrySet().iterator();
while (i.hasNext()) {
Map.Entry<String, Type> e = i.next();
String fName = e.getKey();
String fDesc = e.getValue().getDescriptor();
Type fType = e.getValue();
String mName;
String mDesc;
// generate field
cv.visitField(ACC_PRIVATE, fName, fDesc, null, null).visitEnd();
// generate getter
mName = "get" + up(fName);
mDesc = "()" + fDesc;
mv = cv.visitMethod(ACC_PUBLIC, mName, mDesc, null, null);
if (mv != null) {
mv.visitCode();
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, name, fName, fDesc);
mv.visitInsn(fType.getOpcode(IRETURN));
mv.visitMaxs(fType.getSize(), 1);
mv.visitEnd();
}
// generate setter
mName = "set" + up(fName);
mDesc = "(" + fDesc + ")V";
mv = cv.visitMethod(ACC_PUBLIC, mName, mDesc, null, null);
if (mv != null) {
mv.visitCode();
mv.visitVarInsn(ALOAD, 0);
mv.visitVarInsn(fType.getOpcode(ILOAD), 1);
mv.visitFieldInsn(PUTFIELD, name, fName, fDesc);
mv.visitInsn(RETURN);
mv.visitMaxs(1 + fType.getSize(), 1 + fType.getSize());
mv.visitEnd();
}
}
cv.visitEnd();
}
private static String up(String name) {
return Character.toUpperCase(name.charAt(0)) + name.substring(1);
}
public static final void main(final String[] args) throws Exception {
System.out.println("Running");
Map<String, Type> fields = new HashMap<String, Type>();
fields.put("f0", Type.BOOLEAN_TYPE);
fields.put("f1", Type.INT_TYPE);
fields.put("f2", Type.LONG_TYPE);
fields.put("f3", Type.FLOAT_TYPE);
fields.put("f4", Type.DOUBLE_TYPE);
fields.put("f5", Type.getType("Ljava/lang/String;"));
fields.put("f6", Type.getType("[I"));
BeanGenerator3 cg = new BeanGenerator3("MyBean", fields);
PrintWriter pw = new PrintWriter(System.out, true);
ClassWriter cw = new ClassWriter(0);
CheckClassAdapter ca = new CheckClassAdapter(cw);
cg.generate(ca);
final byte[] b = cw.toByteArray();
Class c = cg.defineClass("MyBean", b, 0, b.length);
Object bean = c.newInstance();
final Class [] c2 = {};
final java.lang.reflect.Method getF = c.getMethod("getF1", c2);
Class[] classes1 = { int.class };
final java.lang.reflect.Method setF = c.getMethod("setF1", classes1);
Object[] args1 = { 999 };
setF.invoke(bean, args1);
// Inoke the getter.
final int val = ((Integer) getF.invoke(bean)).intValue();
System.out.println("Running =>" + val);
}
}