SpringBoot结合JWT怎么实现用户登录功能

要实现SpringBoot结合JWT实现用户登录功能，可以按照以下步骤进行操作：

1. 添加相关依赖：在pom.xml文件中添加Spring Security和JWT的依赖。

<dependency>     <groupId>org.springframework.boot</groupId>     <artifactId>spring-boot-starter-security</artifactId> </dependency>  <dependency>     <groupId>io.jsonwebtoken</groupId>     <artifactId>jjwt</artifactId>     <version>0.9.1</version> </dependency> 

2. 创建用户实体：创建一个用户实体类，包含用户名和密码等属性。

public class User {     private String username;     private String password;      // getter and setter } 

3. 创建用户认证服务：创建一个实现UserDetailsService接口的用户认证服务类，用于加载用户信息。

@Service public class UserDetailsServiceImpl implements UserDetailsService {      @Override     public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {         // 从数据库或其他数据源加载用户信息         User user = userRepository.findByUsername(username);         if (user == null) {             throw new UsernameNotFoundException("User not found");         }         return new org.springframework.security.core.userdetails.User(user.getUsername(), user.getPassword(), new ArrayList<>());     } } 

4. 创建登录控制器：创建一个登录控制器类，用于处理用户登录请求。

@RestController public class LoginController {      @Autowired     private AuthenticationManager authenticationManager;     @Autowired     private JwtUtils jwtUtils;      @PostMapping("/login")     public ResponseEntity<?> login(@RequestBody User user) {         try {             authenticationManager.authenticate(new UsernamePasswordAuthenticationToken(user.getUsername(), user.getPassword()));             String token = jwtUtils.generateToken(user.getUsername());             return ResponseEntity.ok(token);         } catch (Exception e) {             return ResponseEntity.status(HttpStatus.UNAUTHORIZED).build();         }     } } 

5. 创建JWT工具类：创建一个JWT工具类，用于生成和解析JWT。

@Component public class JwtUtils {      private final String secret = "your-secret-key";     private final long expiration = 86400000;      public String generateToken(String username) {         Date now = new Date();         Date expiryDate = new Date(now.getTime() + expiration);          return Jwts.builder()                 .setSubject(username)                 .setIssuedAt(now)                 .setExpiration(expiryDate)                 .signWith(SignatureAlgorithm.HS512, secret)                 .compact();     }      public String getUsernameFromToken(String token) {         return Jwts.parser()                 .setSigningKey(secret)                 .parseClaimsJws(token)                 .getBody()                 .getSubject();     }      public boolean isTokenValid(String token, UserDetails userDetails) {         String username = getUsernameFromToken(token);         return (username.equals(userDetails.getUsername()) && !isTokenExpired(token));     }      private boolean isTokenExpired(String token) {         Date expirationDate = Jwts.parser()                 .setSigningKey(secret)                 .parseClaimsJws(token)                 .getBody()                 .getExpiration();         return expirationDate.before(new Date());     } } 

6. 配置Spring Security：在application.properties文件中配置Spring Security的相关属性。

spring.security.user.name=admin spring.security.user.password=admin spring.security.user.roles=USER,ADMIN 

7. 配置JWT过滤器：创建一个JWT过滤器类，用于验证请求中的JWT并在Security上下文中设置认证信息。

@Component public class JwtTokenFilter extends OncePerRequestFilter {      @Autowired     private JwtUtils jwtUtils;     @Autowired     private UserDetailsServiceImpl userDetailsService;      @Override     protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {         String header = request.getHeader("Authorization");          if (StringUtils.hasText(header) && header.startsWith("Bearer ")) {             String token = header.substring(7);             String username = jwtUtils.getUsernameFromToken(token);              if (StringUtils.hasText(username) && SecurityContextHolder.getContext().getAuthentication() == null) {                 UserDetails userDetails = userDetailsService.loadUserByUsername(username);                  if (jwtUtils.isTokenValid(token, userDetails)) {                     UsernamePasswordAuthenticationToken authenticationToken = new UsernamePasswordAuthenticationToken(userDetails, null, userDetails.getAuthorities());                     authenticationToken.setDetails(new WebAuthenticationDetailsSource().buildDetails(request));                     SecurityContextHolder.getContext().setAuthentication(authenticationToken);                 }             }         }          filterChain.doFilter(request, response);     } } 

8. 配置Spring Security