spring入门3 -- 通过小项目理解IOC

package bean;

public class User {
    private int id;
    private String username;
    private String password;

    public User(int id, String username, String password) {
        this.id = id;
        this.username = username;
        this.password = password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public void setId(int id) {
        this.id = id;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username=‘" + username + ‘\‘‘ +
                ", password=‘" + password + ‘\‘‘ +
                ‘}‘;
    }
}

// UserDao
package dao;

import bean.User;

public interface UserDao {
    User getUser();
}
// DataSources 数据库的相关配置类
package dao.impl;

public class DataSources {
    private String username;
    private String password;
    private String url;
    private String driverClass;

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public String getDriverClass() {
        return driverClass;
    }

    public void setDriverClass(String driverClass) {
        this.driverClass = driverClass;
    }

    public DataSources() {
    }

    public DataSources(String username, String password, String url, String driverClass) {
        this.username = username;
        this.password = password;

        this.url = url;
        this.driverClass = driverClass;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    @Override
    public String toString() {
        return "DataSources{" +
                "username=‘" + username + ‘\‘‘ +
                ", password=‘" + password + ‘\‘‘ +
                ", url=‘" + url + ‘\‘‘ +
                ", driverClass=‘" + driverClass + ‘\‘‘ +
                ‘}‘;
    }
}

// UserDaoImpl 数据库的相关操作
package dao.impl;

import bean.User;
import dao.UserDao;

public class UserDaoImpl implements UserDao {
    DataSources ds;

    public UserDaoImpl() {
    }

    public UserDaoImpl(DataSources ds) {
        this.ds = ds;
    }

    public User getUser() {
        System.out.println("模拟数据库连接" + ds);
        return new User(1, "mark", "1234");
    }
}

// UserService service对外接口
package service;

import bean.User;

public interface UserService {

    User getUser();
}

// UserServiceImpl 处理
package service.impl;

import bean.User;
import dao.UserDao;
import service.UserService;

public class UserServiceImpl implements UserService {
    UserDao userDao;

    public UserServiceImpl() {
    }

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

    public void setUserDao(UserDao ud) {
        this.userDao = ud;
    }

    public UserDao getUserDao() {
        return this.userDao;
    }

    public User getUser() {
        return userDao.getUser();
    }
}

package controller;

import bean.User;
import service.UserService;
import service.impl.UserServiceImpl;

public class UserController {
    UserService userService;

    public void getUser() {
        User user = userService.getUser();
        System.out.println(user);
    }

    public void setUserService(UserServiceImpl userService) {
        this.userService = userService;
    }
}

<?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:p="http://www.springframework.org/schema/p"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
    <!-- 数据库连接 使用property注入 -->
    <bean id="db" class="dao.impl.DataSources">
        <property name="url" value="jdbc:mysql://127.0.0.1:3306/user"/>
        <property name="username" value="root"/>
        <property name="password" value="mysql"/>
        <property name="driverClass" value="com.mysql.jdbc.Driver"/>
    </bean>
    <!-- 数据库操作 使用constructor-arg构造方法进行注入，因为是对象，所以我们使用ref -->
    <bean id="dao" class="dao.impl.UserDaoImpl">
        <constructor-arg index="0" name="ds" ref="db"/>
    </bean>

    <!-- 服务端操作 我们使用p命名空间进行注入，对象所以要加上ref -->
    <bean id="service" class="service.impl.UserServiceImpl" p:userDao-ref="dao"/>

    <!-- 控制层操作 -->
    <bean id="controller" class="controller.UserController" p:userService-ref="service"/>

</beans>

import controller.UserController;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestUser {

    @Test
    public void test(){
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserController uc = context.getBean("controller", UserController.class);
        uc.getUser();

    }
}
//   模拟数据库连接DataSources{username=‘root‘, password=‘mysql‘, url=‘jdbc:mysql://127.0.0.1:3306/user‘, driverClass=‘com.mysql.jdbc.Driver‘}
User{id=1, username=‘mark‘, password=‘1234‘}