jdk6.0从入门到精通-----chapter16反射机制---代理

以下是利用动态代理实现AOP的简单例子

package InvocationHandler;
//业务逻辑接口
public interface BusinessInterface
{
  public void doSomething();
}

package InvocationHandler;
//业务逻辑实体类
public class BusinessObject implements BusinessInterface
{
  public void doSomething()
  {
    System.out.println("方法正在执行...");
  }
}

处理日志等通用逻辑的类

package InvocationHandler;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
//处理日志的类
public class LogHandler implements InvocationHandler 
{  
  private Object delegate; 
  
  public LogHandler(Object delegate)
  { 
    this.delegate = delegate; 
  } 

  public Object invoke(Object proxy, Method method, Object[] args) throws Throwable 
  { 
    Object o = null; 
    try 
    { 
      System.out.println("方法开始..." + method); 
      o = method.invoke( this.delegate,args ); // 调用业务方法
      System.out.println("方法结束..." + method); 
    } 
    catch (Exception e)
    {  
    } 
    return o; 
  } 
}

测试类

package InvocationHandler;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Proxy;

//测试类
public class TestProxy {
	public static void main(String[] args) {
		BusinessInterface businessObject = new BusinessObject();
		InvocationHandler logHandler = new LogHandler(businessObject);

		BusinessInterface proxy = (BusinessInterface) Proxy.newProxyInstance(
				businessObject.getClass().getClassLoader(), businessObject
						.getClass().getInterfaces(), logHandler);

		proxy.doSomething();
	}
}

结果：

方法开始...public abstract void InvocationHandler.BusinessInterface.doSomething()
方法正在执行...
方法结束...public abstract void InvocationHandler.BusinessInterface.doSomething()