spring(3)

 

 

package com.cn.pojo;

import org.springframework.stereotype.Component;

@Component
public class Book {

}

package com.cn.dao;

import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Repository;

@Repository
@Scope("prototype")
public class BookDao {

}

package com.cn.dao;

import org.springframework.stereotype.Repository;

@Repository
public class BookExt extends BookDao{

}

package com.cn.controller;

import org.springframework.stereotype.Controller;

@Controller
public class BookController {

}

package com.cn.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Service;

import com.cn.dao.BookDao;

@Service
public class BookService {
    
/**
     * @Autowired 实现自动注入<br/>
     *     1、先按类型查找并注入<br/>
     *  2、如果找到多个，就接着按属性名做为id继续查找并注入<br/>
     *  3、如果找到多个。但是属性名做为id找不到，可以使用@Qualifier("bookDao")注解指定id查找并注入<br/>
     *  4、可以通过修改@Autowired(required=false)允许字段值为null
     */
    @Autowired(required=false)
    @Qualifier("bookDaoExt")
    private BookDao bookDao1;
    
    /**
     * @Autowired标注在方法上，那么此方法会在对象创建之后调用。
     *         1、先按类型查找参数并调用方法传递<br/>
     *         2、如果找到多个，就接着按参数名做为id继续查找并注入<br/>
     *        3、如果找到多个。但是参数名做为id找不到，可以使用@Qualifier("bookDao")注解指定id查找并调用<br/>
     *      4、可以通过修改@Autowired(required=false)允许不调用此方法也不报错
     */
    @Autowired(required=false)
    public void setBookDao(@Qualifier("bookExt")BookDao abc) {
        System.out.println("BookDao进来啦 --->>> " + abc);
    }
    

    @Override
    public String toString() {
        return "BookService [bookDao=" + bookDao1 + "]";
    }
}

package com.cn.test;

import static org.junit.Assert.*;

import org.junit.Test;
import org.springframework.beans.factory.annotation.Configurable;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class SpringTest {
    @Test
    public void test1() throws Exception {

        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        /*
         * System.out.println(applicationContext.getBean("bookDao"));
         * System.out.println(applicationContext.getBean("bookDao"));
         * System.out.println(applicationContext.getBean("bookDao"));
         * 
         * 
         * System.out.println(applicationContext.getBean("book"));
         */
        System.out.println(applicationContext.getBean("bookService"));

    }

}

<?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"
    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-4.3.xsd">


    <!-- 配置包扫描 base-package 设置需要扫描的包名（它的子包也会被扫描） use-default-filters="false" 
        去掉包扫描时默认包含规则 -->
    <context:component-scan base-package="com.cn"   >

    <!--      排除 按照注解
        <context:exclude-filter type="annotation"
            expression="org.springframework.stereotype.Service" />
        排除 按类排除

        <context:exclude-filter type="assignable"
            expression="com.cn.controller.BookController" />
 -->


<!-- 包含 按照注解 -->
        <!-- <context:include-filter type="annotation"
            expression="org.springframework.stereotype.Service" />
 -->

<!-- 包含按类排除
 -->
        <!-- <context:include-filter type="assignable"
            expression="com.cn.controller.BookController" />
 -->
    </context:component-scan>
</beans>