Java Spring登录练习详解

目录

• 编写Massage类和User类（方便后面使用）
• 三层内容
• 编写测试文件
• pom.xml和spring.xml配置
• 总结

//---------------------Massage-----------------------
public class Massage {
    //登录成功状态码和提示信息
    //此处省略set/get/toString/构造器这些方法
    private int logincode;
	private String loginmsg;
}
//-------------------User.java-----------------------
public class User{
//用户名和密码此处省略set/get/toString/构造器这些方法
    private String uname;
    private String upsw;
}

//-----------------UserDao.java----------------------
@Repository
public class LoginDao {
    //定义用户名和密码
    private final String UNAME="admin";
    private final String UPSW="admin";
    //通过用户名查询
    public User bynameselectpsw(String name){
        //判读是否是空值
        if(name!=null && name.length()!=0 && UNAME.equals(name)){
            User user=new User();
            user.setUname(UNAME);
            user.setUpsw(UPSW);
            return user;
        }
        return null;
    }
}
//-----------------UserService.java------------------
@Service
public class LoginService {
    @Autowired
    LoginDao dao;
    //编写逻辑层对密码和用户名的判断
    public  Massage loginCheck(String uname,String psw){
        Massage msg=new Massage();
        //判断密码和账号是否为空
        if(uname==null || uname.length()==0){
            msg.setLoginmsg("用户名不能为空");
            msg.setLogincode(0);
            return msg;
        }
        if(psw==null || psw.length()==0){
            msg.setLoginmsg("密码不能为空");
            msg.setLogincode(0);
            return msg;
        }
        //判断是否有此用户
        User user=dao.bynameselectpsw(uname);
        System.out.println(user);
        if(user==null){
            msg.setLoginmsg("无此用户~");
            msg.setLogincode(0);
            return msg;
        }
        //对密码进行判断
        if(user.getUpsw()!=psw){
            msg.setLoginmsg("密码不正确~");
            msg.setLogincode(0);
            return msg;
        }
        //以上都没触发则登录成功
        msg.setLoginmsg("登录成功~");
        msg.setLogincode(1);
        return msg;
    }
}
//-----------------UserController.java---------------
@Controller
public class LoginController  {
    @Autowired
    LoginService service;
    public Massage controller(String name, String psw){
        Massage msg=service.loginCheck(name,psw);
        return msg;
    }
}

public class LoginTest {
    @Test
    public void test(){
        //获取核心配置文件
        ApplicationContext app=new ClassPathXmlApplicationContext("spring.xml");
        //获取Controller对象
        LoginController lg= app.getBean("loginController",LoginController.class);
       // Massage msg=lg.controller("admin","admin");
        Massage msg=lg.controller("","");
        System.out.println(msg);
    }
}

 <!-- 添加Spring框架的核心依赖 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>5.2.4.RELEASE</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/javax.annotation/javax.annotation-api -->
    <dependency>
      <groupId>javax.annotation</groupId>
      <artifactId>javax.annotation-api</artifactId>
      <version>1.3.2</version>
    </dependency>

<context:component-scan base-package="com.yjxxt"></context:component-scan>