Java javassist动态代理

 package org.windwant.spring.core.proxy;

 import javassist.ClassPool;
 import javassist.CtClass;
 import javassist.CtMethod;

 /**
  * Created by windwant on 2016/9/18.
  */
 public class MyJavassistProxy {

     public Object getProxySelf(String clazz, String pClazz, String methodName, String methodBefore, String methodAfter){
         ClassPool cp = ClassPool.getDefault();
         CtClass ct;
         try {
             ct = cp.get(clazz);
             if(pClazz != null){
                 ct.setSuperclass(cp.get(pClazz));
             }
             ct.writeFile();
             ct.defrost();
             CtMethod m = ct.getDeclaredMethod(methodName);
             if(methodBefore != null) {
                 m.insertBefore(methodBefore);
             }
             if(methodAfter != null) {
                 m.insertAfter(methodAfter);
             }
             Class c = ct.toClass();
             return c.newInstance();
         } catch (Exception e) {
             e.printStackTrace();
         }
         return null;
     }

 }

 public void testJavassist(){
         String clazz = "org.windwant.spring.core.proxy.Hello";
         String methodBefore = "{ System.out.println(\"method before...:\"); }";
         String methodAfter = "{ System.out.println(\"method after...:\"); }";
         String pClazz = "org.windwant.spring.core.proxy.HelloP";

         Hello hello = (Hello) new MyJavassistProxy().getProxySelf(clazz, null, "say",
                 methodBefore, methodAfter);
         hello.say();
     }