下面以属性setter方法注入为例，实现一个简单的登录验证。具体实现步骤如下所示。
（1）编写DAO层：在项目的com.lq包下新建dao包，在dao包下创建接口UserDao.java，在UserDao.java接口中添加方法login()，用于实现登录功能。
package com.lq.dao;
/**
* @Author: Luqing Teacher
* @CreateTime: 2024-11-29
* @Description: 接口类UserDao实现
* @Version: 1.0
*/
public interface UserDao {
public boolean login(String name, String pwd);
}
（2）编写DAO层的实现类：在com.lq.dao包下创建impl包，在impl包下创建UserDao接口的实现类UserDaoImpl，在UserDaoImpl类中实现login()方法。
package com.lq.dao.impl;
import com.lq.dao.UserDao;
/**
* @Author: Luqing Teacher
* @CreateTime: 2024-11-29
* @Description: UserDaoImpl 接口实现类
* @Version: 1.0
*/
public class UserDaoImpl implements UserDao {
@Override
public boolean login(String name, String pwd) {
if (name.equals("张三") && pwd.equals("123")){
return true;
}
return false;
}
}
（3）编写Service层：在项目的com.lq包下新建service包，在service包下创建接口UserService.java，在接口中添加方法login()。
package com.lq.service;
/**
* @Author: lzq
* @CreateTime: 2024-11-29
* @Description: UserService服务接口类
* @Version: 1.0
*/
public interface UserService {
public boolean login(String name, String pwd);
}
（4）编写Service层实现类：在com.lq.service包下创建impl包，在impl包下创建UserService接口的实现类UserServiceImpl，在UserServiceImpl类中实现login()方法。
package com.lq.service.impl;
import com.lq.dao.UserDao;
import com.lq.service.UserService;
/**
* @Author: Luqing Teacher
* @CreateTime: 2024-11-29
* @Description: UserServiceImpl实现类
* @Version: 1.0
*/
public class UserServiceImpl implements UserService {
UserDao userDao;
public void setUserDao(UserDao userDao) {
this.userDao = userDao;
}
@Override
public boolean login(String name, String pwd) {
return userDao.login(name, pwd);
}
}
（5）编写applicationContext-login.xml配置文件：使用<bean>元素添加创建的UserDaoImpl类和UserServiceImpl类的实例，并配置其相关属性。
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="userDao" class="com.lq.dao.impl.UserDaoImpl"/>
<bean id="userService" class="com.lq.service.impl.UserServiceImpl">
<property name="userDao" ref="userDao"/>
</bean>
</beans>
(6) 编写测试类：在com.lq的测试包中新建测试类TestLogin。
package com.lq.test;
import com.lq.service.UserService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
* @Author: Luqing Teacher
* @CreateTime: 2024-11-29
* @Description: TestLogin测试登陆验证
* @Version: 1.0
*/
public class TestLogin{
public static void main(String[] args) {
ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext-login.xml");
UserService userService = (UserService) applicationContext.getBean("userService");
boolean flag = userService.login("admin", "123");
if (flag){
System.out.println("登陆成功");
}else {
System.out.println("登陆失败");
}
}
}
运行结果如下：
