Java动态代理实现方法小结

public interface ISomeService {
  String doFirst();
  void doSecond();
  String doThird();
}
//目标类：代理类要增强的类
public class SomeServiceImpl implements ISomeService {
  @Override
  public String doFirst() {
    return "AAAbbb";
  }
  @Override
  public void doSecond() {
    System.out.println("SomeServiceImpl：执行doSecond()");
  }
  @Override
  public String doThird() {
    return "aaa";
  }
}
public class Mytest {
  public static void main(String[] args) {
    ISomeService target = new SomeServiceImpl();
    ISomeService someService = (ISomeService) Proxy.newProxyInstance(
        target.getClass().getClassLoader(),
        target.getClass().getInterfaces(),
        new InvocationHandler() {
          // proxy：代理对象
          // method：目标方法
          // args：目标方法的参数列表
          @Override
          public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
            Object result = method.invoke(target, args);
            if(result!=null) {
              result=((String)result).toUpperCase();
            }
            return result;
          }
        });
    System.out.println(someService.doFirst());
    someService.doSecond();
    System.out.println(someService.doThird());
  }
}

//目标类：代理类要增强的类
public class SomeService {
  public String doFirst() {
    System.out.println("SomeServiceImpl：执行doFirst()");
    return "AAAbbb";
  }
  public void doSecond() {
    System.out.println("SomeServiceImpl：执行doSecond()");
  }
}
//注意：使用Cglib动态代理，要求目标类不能是final的
//Cglib动态代理的增强原理是：子类增强父类，所以目标类必须能被继承
public class CglibFactory implements MethodInterceptor {
  private SomeService target;
  public CglibFactory() { }
  public CglibFactory(SomeService target) {
    this.target = target;
  }
  public SomeService myCglibCreator() {
    Enhancer enhancer = new Enhancer();
    //指定父类，即目标类。因为Cglib动态代理增强的原理是：子类增强父类
    enhancer.setSuperclass(SomeService.class);
    //设置回调接口对象
    enhancer.setCallback(this);
    //create()方法用于创建Cglib动态代理对象
    return (SomeService)enhancer.create();
  }
  //回调函数的执行条件：代理对象执行目标方法时会触发该方法
  @Override
  public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
    Object invoke = method.invoke(target, args);
    if(invoke!=null) {
      invoke=((String)invoke).toUpperCase();
    }
    return invoke;
  }
}
public class Mytest {
  public static void main(String[] args) {
    SomeService target = new SomeService();
    SomeService proxy = new CglibFactory(target).myCglibCreator();
    proxy.doFirst();
  }
}

public interface ISomeService {
  String doFirst();
  void doSecond();
  String doThird();
}
//目标类：代理类要增强的类
public class SomeService implements ISomeService {
  public String doFirst() {
    return "AAAbbb";
  }
  public void doSecond() {
    System.out.println("SomeServiceImpl：执行doSecond()");
  }
  @Override
  public String doThird() {
    return "third";
  }
}
//注意：使用Cglib动态代理，要求目标类不能是final的
//Cglib动态代理的增强原理是：子类增强父类，所以目标类必须能被继承
public class CglibFactory implements MethodInterceptor {
  private ISomeService target;
  public CglibFactory() { }
  public CglibFactory(ISomeService target) {
    this.target = target;
  }
  public ISomeService myCglibCreator() {
    Enhancer enhancer = new Enhancer();
    //指定父类，即目标类。因为Cglib动态代理增强的原理是：子类增强父类
    enhancer.setSuperclass(ISomeService.class);
    //设置回调接口对象
    enhancer.setCallback(this);
    //create()方法用于创建Cglib动态代理对象
    return (ISomeService)enhancer.create();
  }
  //回调函数的执行条件：代理对象执行目标方法时会触发该方法
  @Override
  public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
    Object invoke = method.invoke(target, args);
    if(invoke!=null) {
      invoke=((String)invoke).toUpperCase();
    }
    return invoke;
  }
}
public class Mytest {
  public static void main(String[] args) {
    ISomeService target = new SomeService();
    ISomeService proxy = new CglibFactory(target).myCglibCreator();
    System.out.println(proxy.doFirst());
    proxy.doSecond();
    System.out.println(proxy.doThird());
  }
}