Spring学习笔记（六）模拟实际开发过程的调用过程XML版-构造函数注入

用Spring的XML版的构造函数注入完成这个过程

源码获取github

1.项目结构

2.jar包

<dependencies>
  <dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.11</version>
    <scope>test</scope>
  </dependency>

  <!-- https://mvnrepository.com/artifact/org.springframework/spring-aop -->
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-aop</artifactId>
    <version>4.3.6.RELEASE</version>
  </dependency>
  <!-- https://mvnrepository.com/artifact/org.springframework/spring-aspects -->
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-aspects</artifactId>
    <version>4.3.6.RELEASE</version>
  </dependency>
  <!-- https://mvnrepository.com/artifact/org.springframework/spring-beans -->
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-beans</artifactId>
    <version>4.3.6.RELEASE</version>
  </dependency>
  <!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>4.3.6.RELEASE</version>
  </dependency>
  <!-- https://mvnrepository.com/artifact/org.springframework/spring-context-support -->
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context-support</artifactId>
    <version>4.3.6.RELEASE</version>
  </dependency>
  <!-- https://mvnrepository.com/artifact/org.springframework/spring-core -->
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-core</artifactId>
    <version>4.3.6.RELEASE</version>
  </dependency>
  <!-- https://mvnrepository.com/artifact/org.springframework/spring-expression -->
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-expression</artifactId>
    <version>4.3.6.RELEASE</version>
  </dependency>
  <!-- https://mvnrepository.com/artifact/org.springframework/spring-tx -->
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-tx</artifactId>
    <version>4.3.6.RELEASE</version>
  </dependency>

</dependencies>

3.代替private UserDao userDao = new userDaoImpl();

UserServiceImpl.java

package com.hs.service.impl;

import com.hs.dao.UserDao;
import com.hs.service.UserService;

public class UserServiceImpl implements UserService {

   private UserDao userDao;

   public UserServiceImpl() {
   }

   public UserServiceImpl(UserDao userDao) {
      this.userDao = userDao;
   }

   @Override
   public void add() {
      System.out.println("UserService层的实现类--->ADD");
      userDao.add();
   }
}

beans.xml

<!--实例化-->
<bean id="userDaoImpl" class="com.hs.dao.impl.UserDaoImpl">
</bean>
<!--通过构造函数实例化-->
<bean id="userServiceImpl" class="com.hs.service.impl.UserServiceImpl">
   <constructor-arg name="userDao" ref="userDaoImpl"/>
</bean>

这两段代码相当于，完成了private UserDao userDao = new userDaoImpl();

4.代替private UserService userService = new userServiceImpl();

UserController.java

package com.hs.web;

import com.hs.service.UserService;

public class UserController {

   private UserService userService;

   public UserController() {
   }

   public UserController(UserService userService) {
      this.userService = userService;
   }

   public void add() {
      System.out.println("UserController层--->ADD");
      userService.add();
   }
}

beans.xml

<bean id="userServiceImpl" class="com.hs.service.impl.UserServiceImpl">
   <constructor-arg name="userDao" ref="userDaoImpl"/>
</bean>
<bean id="userController" class="com.hs.web.UserController">
   <constructor-arg name="userService">
      <ref bean="userServiceImpl"/>
   </constructor-arg>
</bean>

这两段代码相当于，完成了private UserService userService = new userServiceImpl();

5.代替UserController userController = new UserController();

测试

package com.hs.test;

import com.hs.web.UserController;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MethodTest {

    @Test
    public void test01() {
        // 1.读取配置文件
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("beans.xml");
        //获取xml版本里的UserController userController = new UserController();
        UserController userController = applicationContext.getBean("userController", UserController.class);
        userController.add();
    }

}

控制台输出：

UserController层—>ADD
UserService层的实现类—>ADD
UserDao层的实现类—>ADD