字节码操作、javassist使用

package cn.lhl.test;

import javassist.CannotCompileException;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtConstructor;
import javassist.CtField;
import javassist.CtMethod;

/**
 * 测试使用javassist生成一个新的类
 * 
 * @author Administrator
 *
 */
public class Demo01 {
	public static void main(String[] args) throws Exception {
		ClassPool pool = ClassPool.getDefault();
		CtClass cc = pool.makeClass("cn.lhl.bean.Emp");
		
		//源码操作
		//创建属性
		CtField f1 = CtField.make("private int empno;", cc);
		CtField f2 = CtField.make("private String ename;", cc);
		cc.addField(f1);
		cc.addField(f2);
		
		//创建方法
		CtMethod m1 = CtMethod.make("public int getEmpno(){return empno;}", cc);
		CtMethod m2 = CtMethod.make("public void setEmpno(int empno){this.empno=empno;})", cc);
		cc.addMethod(m1);
		cc.addMethod(m2);
		
		//添加构造器
		CtConstructor constructor = new CtConstructor(new CtClass[] {CtClass.intType,
				pool.get("java.lang.String")},cc);
		constructor.setBody("{this.empno=empno;this.ename=ename;}");
		cc.addConstructor(constructor);
		
		//将上面构造好的类写入到f：/myjava中
		cc.debugWriteFile("f:/myjava");
		System.out.println("生成类");
	}
}

package cn.lhl.test;

public class Emp {
	
	private int empno;
	private String ename;
	
	public int getEmpno() {
		return empno;
	}
	public void setEmpno(int empno) {
		this.empno = empno;
	}
	public String getEname() {
		return ename;
	}
	public void setEname(String ename) {
		this.ename = ename;
	}
	
	public Emp(int empno, String ename) {
		super();
		this.empno = empno;
		this.ename = ename;
	}
	
	public Emp() {
	}
}