<dependency>
 <groupId>io.jsonwebtoken</groupId>
 <artifactId>jjwt</artifactId>
 <version>0.9.0</version>
</dependency>

jwt: 
 header: JWTHeaderName
 secret: aabbccdd 
 expiration: 3600000 

@Data
@ConfigurationProperties(prefix = "jwt") //配置自動加載，prefix是配置的前綴
@Component
public class JwtTokenUtil implements Serializable {
 private String secret;
 private Long expiration;
 private String header;
 /**
 * 生成token令牌
 *
 * @param userDetails 用戶
 * @return 令token牌
 */
 public String generateToken(UserDetails userDetails) {
 Map<String, Object> claims = new HashMap<>(2);
 claims.put("sub", userDetails.getUsername());
 claims.put("created", new Date());
 return generateToken(claims);
 }
 /**
 * 從令牌中獲取用戶名
 *
 * @param token 令牌
 * @return 用戶名
 */
 public String getUsernameFromToken(String token) {
 String username;
 try {
  Claims claims = getClaimsFromToken(token);
  username = claims.getSubject();
 } catch (Exception e) {
  username = null;
 }
 return username;
 }
 /**
 * 判斷令牌是否過期
 *
 * @param token 令牌
 * @return 是否過期
 */
 public Boolean isTokenExpired(String token) {
 try {
  Claims claims = getClaimsFromToken(token);
  Date expiration = claims.getExpiration();
  return expiration.before(new Date());
 } catch (Exception e) {
  return false;
 }
 }
 /**
 * 刷新令牌
 *
 * @param token 原令牌
 * @return 新令牌
 */
 public String refreshToken(String token) {
 String refreshedToken;
 try {
  Claims claims = getClaimsFromToken(token);
  claims.put("created", new Date());
  refreshedToken = generateToken(claims);
 } catch (Exception e) {
  refreshedToken = null;
 }
 return refreshedToken;
 }
 /**
 * 驗證令牌
 *
 * @param token 令牌
 * @param userDetails 用戶
 * @return 是否有效
 */
 public Boolean validateToken(String token, UserDetails userDetails) {
 SysUser user = (SysUser) userDetails;
 String username = getUsernameFromToken(token);
 return (username.equals(user.getUsername()) && !isTokenExpired(token));
 }
 /**
 * 從claims生成令牌,如果看不懂就看誰調用它
 *
 * @param claims 數據聲明
 * @return 令牌
 */
 private String generateToken(Map<String, Object> claims) {
 Date expirationDate = new Date(System.currentTimeMillis() + expiration);
 return Jwts.builder().setClaims(claims)
    .setExpiration(expirationDate)
    .signWith(SignatureAlgorithm.HS512, secret)
    .compact();
 }
 /**
 * 從令牌中獲取數據聲明,如果看不懂就看誰調用它
 *
 * @param token 令牌
 * @return 數據聲明
 */
 private Claims getClaimsFromToken(String token) {
 Claims claims;
 try {
  claims = Jwts.parser().setSigningKey(secret).parseClaimsJws(token).getBody();
 } catch (Exception e) {
  claims = null;
 }
 return claims;
 }
}

@RESTCONTROLLER
PUBLIC CLASS JWTAUTHCONTROLLER {
 @RESOURCE
 PRIVATE JWTAUTHSERVICE JWTAUTHSERVICE;
 @POSTMAPPING(VALUE = "/AUTHENTICATION")
 PUBLIC AJAXRESPONSE LOGIN(@REQUESTBODY MAP<STRING, STRING> MAP) {
  STRING USERNAME = MAP.GET("USERNAME");
  STRING PASSWORD = MAP.GET("PASSWORD");
  IF (STRINGUTILS.ISEMPTY(USERNAME) || STRINGUTILS.ISEMPTY(PASSWORD)) {
   RETURN AJAXRESPONSE.ERROR(
    NEW CUSTOMEXCEPTION(CUSTOMEXCEPTIONTYPE.USER_INPUT_ERROR,"用戶名密碼不能為空"));
  }
  RETURN AJAXRESPONSE.SUCCESS(JWTAUTHSERVICE.LOGIN(USERNAME, PASSWORD));
 }
 @POSTMAPPING(VALUE = "/REFRESHTOKEN")
 PUBLIC AJAXRESPONSE REFRESH(@REQUESTHEADER("${JWT.HEADER}") STRING TOKEN) {
  RETURN AJAXRESPONSE.SUCCESS(JWTAUTHSERVICE.REFRESHTOKEN(TOKEN));
 }
}

@Service
public class JwtAuthService {
 @Resource
 private AuthenticationManager authenticationManager;
 @Resource
 private UserDetailsService userDetailsService;
 @Resource
 private JwtTokenUtil jwtTokenUtil;

 public String login(String username, String password) {
  //使用用戶名密碼進行登錄驗證
  UsernamePasswordAuthenticationToken upToken = 
     new UsernamePasswordAuthenticationToken( username, password );
  Authentication authentication = authenticationManager.authenticate(upToken); 
  SecurityContextHolder.getContext().setAuthentication(authentication);
  //生成JWT
  UserDetails userDetails = userDetailsService.loadUserByUsername( username );
  return jwtTokenUtil.generateToken(userDetails);
 }

 public String refreshToken(String oldToken) {
  if (!jwtTokenUtil.isTokenExpired(oldToken)) {
   return jwtTokenUtil.refreshToken(oldToken);
  }
  return null;
 }
}

@Bean(name = BeanIds.AUTHENTICATION_MANAGER)
@Override
public AuthenticationManager authenticationManagerBean() throws Exception {
 return super.authenticationManagerBean();
}

@Slf4j
@Component
public class JwtAuthenticationTokenFilter extends OncePerRequestFilter {

 @Resource
 private MyUserDetailsService userDetailsService;

 @Resource
 private JwtTokenUtil jwtTokenUtil;

 @Override
 protected void doFilterInternal(HttpServletRequest request,
         HttpServletResponse response,
         FilterChain chain) throws ServletException, IOException {
 
  // 從這里開始獲取 request 中的 jwt token
  String authHeader = request.getHeader(jwtTokenUtil.getHeader());
  log.info("authHeader：{}", authHeader);
  // 驗證token是否存在
  if (authHeader != null && StringUtils.isNotEmpty(authHeader)) {
   // 根據token 獲取用戶名
   String username = jwtTokenUtil.getUsernameFromToken(authHeader);
   if (username != null && SecurityContextHolder.getContext().getAuthentication() == null) {
    // 通過用戶名 獲取用戶的信息
    UserDetails userDetails = this.userDetailsService.loadUserByUsername(username);
    
    // 驗證JWT是否過期
    if (jwtTokenUtil.validateToken(authHeader, userDetails)) {
     //加載用戶、角色、權限信息，Spring Security根據這些信息判斷接口的訪問權限
     UsernamePasswordAuthenticationToken authentication 
       = new UsernamePasswordAuthenticationToken(userDetails, null, 
                  userDetails.getAuthorities());
     authentication.setDetails(new WebAuthenticationDetailsSource()
           .buildDetails(request));
     SecurityContextHolder.getContext().setAuthentication(authentication);
    }
   }
  }
  chain.doFilter(request, response);
 }
}

.sessionManagement()
 .sessionCreationPolicy(SessionCreationPolicy.STATELESS)
 .and()
.addFilterBefore(jwtAuthenticationTokenFilter, UsernamePasswordAuthenticationFilter.class);