Spring+MongoDB实现登录注册功能

下面就为你讲解如何使用Spring和MongoDB实现登录注册功能。

准备工作

• 安装并启动MongoDB服务器
• 创建Maven项目，引入所需依赖

xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>

实现注册功能

1. 编写User类用来保存用户信息，包含用户名和密码字段
   ```java
   @Data
   @Document(collection = "user")
   public class User implements UserDetails {
   @Id
   private String id;
   private String username;
   private String password;
   private boolean accountNonExpired = true;
   private boolean accountNonLocked = true;
   private boolean credentialsNonExpired = true;
   private boolean enabled = true;

   //省略方法
   

   }
   2 .编写UserController实现注册java
   @RestController
   @RequestMapping("/user")
   public class UserController {

   private final BCryptPasswordEncoder passwordEncoder;
   
   private final UserService userService;
   
   public UserController(UserService userService, BCryptPasswordEncoder passwordEncoder) {
       this.userService = userService;
       this.passwordEncoder = passwordEncoder;
   }
   
   @PostMapping("/register")
   public ResponseEntity<User> register(@RequestBody User user) {
       String encodedPassword = passwordEncoder.encode(user.getPassword());
       user.setPassword(encodedPassword);
       User newUser = userService.saveUser(user);
       return ResponseEntity.ok(newUser);
   }
   

   }
   3. 编写UserService，其中saveUser用于将用户信息保存到MongoDB中java
   @Service
   public class UserServiceImpl implements UserService, UserDetailsService {

   private final UserRepository userRepository;
   
   public UserServiceImpl(UserRepository userRepository) {
       this.userRepository = userRepository;
   }
   
   @Override
   public User saveUser(User user) {
       return userRepository.save(user);
   }
   
   @Override
   public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
       User user = userRepository.findByUsername(username);
       if (user == null) {
           throw new UsernameNotFoundException("用户不存在");
       }
       return user;
   }
   

   }
   4. 编写UserRepository，使用Spring Data MongoDB来进行数据库操作java
   public interface UserRepository extends MongoRepository {
   User findByUsername(String username);
   }
   ```

实现登录功能

1. 在Spring Security配置类中配置使用UserDetailsService进行身份认证
   ```java
   @Configuration
   @EnableWebSecurity
   @AllArgsConstructor
   public class SecurityConfig extends WebSecurityConfigurerAdapter {

   private final UserService userService;
   
   @Bean
   public BCryptPasswordEncoder passwordEncoder() {
       return new BCryptPasswordEncoder();
   }
   
   @Override
   protected void configure(AuthenticationManagerBuilder auth) throws Exception {
       auth.userDetailsService(userService).passwordEncoder(passwordEncoder());
   }
   
   //省略其他配置
   

   }
   2. 编写登录接口java
   @RestController
   @RequestMapping("/user")
   public class UserController {

   //省略其他代码
   
   @PostMapping("/login")
   public ResponseEntity<String> login(HttpServletRequest request,
                                       @RequestParam String username,
                                       @RequestParam String password) {
       try {
           request.login(username, password);
       } catch (ServletException e) {
           return ResponseEntity.status(HttpStatus.UNAUTHORIZED).build();
       }
       return ResponseEntity.ok("登录成功");
   }
   

   }
   ```
   3. 编写登录页面和注册页面，使用表单提交用户名和密码的方式来进行登录和注册

综上所述，使用以上方式就可以在Spring和MongoDB中实现简单的登录注册功能。

示例：

1. 在MongoDB中创建名为test的数据库，运行以下示例代码，创建用户名密码分别为test、123456的用户

```java
@RestController
@RequestMapping("/user")
public class UserController {

   private final UserService userService;

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

   @GetMapping("/save")
   public ResponseEntity<User> save() {
       User user = new User();
       user.setUsername("test");
       user.setPassword("123456");
       User newUser = userService.saveUser(user);
       return ResponseEntity.ok(newUser);
   }

}
```

1. 使用Postman发送POST请求到http://localhost:8080/user/register，请求Body为以下JSON数据：

json
{
"username": "test",
"password": "123456"
}

若收到{"id":"xxx", "username":"test", "password":"$2a$10$xxx","accountNonExpired":true,"accountNonLocked":true,"credentialsNonExpired":true,"enabled":true}则表示注册成功。

1. 配置Spring Security，使/user/login接口需要身份认证

```java
@Configuration
@EnableWebSecurity
@AllArgsConstructor
public class SecurityConfig extends WebSecurityConfigurerAdapter {

   private final UserService userService;

   //省略其他代码

   @Override
   protected void configure(HttpSecurity http) throws Exception {
       http.authorizeRequests()
               .antMatchers("/user/register").permitAll()
               .anyRequest().authenticated()
               .and()
               .formLogin()
               .permitAll();
   }

}
```

1. 使用Postman发送POST请求到http://localhost:8080/user/login?username=test&password=123456，若收到登录成功则表示登录成功。

以上就是使用Spring和MongoDB实现登录注册功能的完整攻略。