Spring中應用java動態代碼實現Aop

用三個類來舉例說明java動態代碼實現方法

Spring的做法，基於接口的用proxy

普通接口類

package com.jamesby.proxy;   
public interface CarCompany {   
  
    public void makeCar();    
    public void abc();   
} 

實現接口類

package com.jamesby.proxy;   
 
public class CarCompanyImpl implements CarCompany {   
    public void makeCar() {   
        System.out.println("Company A make a car!");   
        abc();   
    }   
    public void abc()   
    {   
        System.out.println("abc is invoked!");   
    }   
}

動態代理句柄

package com.jamesby.proxy;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;

public class CarCompanyHandler implements InvocationHandler {
	CarCompany com;

	public CarCompanyHandler(CarCompany com) {
		this.com = com;
	}

	public Object invoke(Object proxy, Method method, Object[] args)
			throws Throwable {
		System.out.println("time1:" + System.currentTimeMillis());
		method.invoke(this.com, new Object[]{});
		System.out.println("time2:" + System.currentTimeMillis());
		return null;
	}
}

測試類

package com.jamesby.proxy;   
  
import java.lang.reflect.Proxy;   
  
public class Test {   
    public static void main(String[] arg) {   
        CarCompanyImpl a = new CarCompanyImpl();   
        CarCompanyHandler handler = new CarCompanyHandler(a);   
        // 產生一個新的代理類   
        CarCompany com = (CarCompany) Proxy.newProxyInstance(Test.class  
                .getClassLoader(), new Class[] { CarCompany.class }, handler);   
        com.makeCar(); 
    }   
}

此時就可以實現代碼