Spring框架中的aop操作之二 通過配置文件實現增強

配置文件代碼：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
         http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
    <!-- 開啟註解掃描 -->
    <context:component-scan base-package="com.swift"></context:component-scan>
    
    <bean id="book" class="com.swift.aop.Book"></bean>
    <bean id="adviceBook" class="com.swift.aop.AdviceBook"></bean>
    
    <aop:config>
    <!-- 切入點表達式第一個*表示public private等許可權後接空格，第二個*表示任意方法(..)表示參數 -->
    <aop:pointcut expression="execution(* com.swift.aop.Book.*())" id="pointcut1"/>
    
    <!-- 哪個切麵（用來增強切入點的類） 名稱是什麼用ref表示 -->
    <aop:aspect ref="adviceBook">
    <!-- 增強的具體方法，增強哪個切入點 -->
    <aop:before method="before" pointcut-ref="pointcut1"/>
    </aop:aspect>
    </aop:config>
</beans>

包括bean context aop三個約束

以及切麵的配置——表達式execution含義、advice通知/增強設置

連接點joinpoint的類，即需要被增強的類：

package com.swift.aop;

public class Book {
    public String fun() {
        System.out.println("This is Book's fun()..............");
        return "This is Book's fun()..............";
    }
}

進行切麵操作的類：

package com.swift.aop;

public class AdviceBook {
    public String before() {
        System.out.println("This is AdviceBook's before()...............");
        return "This is AdviceBook's before()...............";
    }
}

測試的類：

package com.swift.web;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.swift.aop.Book;
@WebServlet("/test")
public class ServleTest extends HttpServlet {
    private static final long serialVersionUID = 1L;
    public ServleTest() {
        super();
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.getWriter().append("Served at: ").append(request.getContextPath());
        ApplicationContext context=new ClassPathXmlApplicationContext("aop.xml");
        Book book=(Book)context.getBean("book");
        response.getWriter().append(book.fun());
    }
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

}

演示效果圖：

瀏覽器無反應

只有Book的方法，沒有前置的before，想來應該是調用了但是返回的字元串沒能顯示在瀏覽器上

控制台console成功

前置增強在切入點前輸出