springBoot实现JWT步骤

	com.auth0
	java-jwt
	3.11.0

主要功能生成token

public class JwtUtil {
   
    private static final long EXPIRE_TIME = 5 * 60 * 1000;
    
    private static final String SECRET = "jwt_secret";

    
    public static String sign(String userId,Map info) {
        try {
            Date date = new Date(System.currentTimeMillis() + EXPIRE_TIME);
            Algorithm algorithm = Algorithm.HMAC256(SECRET);
            return JWT.create()
                    // 将 user id 保存到 token 里面
                    .withAudience(userId)
                    // 存放自定义数据
                    .withClaim("info", info)
                    // 五分钟后token过期
                    .withExpiresAt(date)
                    // token 的密钥
                    .sign(algorithm);
        } catch (Exception e) {
           e.printStackTrace();
            return null;
        }
    }

    
    public static String getUserId(String token) {
        try {
            String userId = JWT.decode(token).getAudience().get(0);
            return userId;
        } catch (JWTDecodeException e) {
            return null;
        }
    }
    
    
    public static Map getInfo(String token) {
        try {
            return JWT.decode(token).getClaim("info").asMap();
        } catch (JWTDecodeException e) {
            return null;
        }
    }
    

    
    public static boolean checkSign(String token) {
        try {
            Algorithm algorithm = Algorithm.HMAC256(SECRET);
            JWTVerifier verifier = JWT.require(algorithm)
                    // .withClaim("username", username)
                    .build();
            verifier.verify(token);
            return true;
        } catch (JWTVerificationException exception) {
            throw new RuntimeException("token 无效，请重新获取");
        }
    }
}

public class JwtInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object object) {
       // 如果不是映射到方法直接通过
       if(!(object instanceof HandlerMethod)){
          return true;
       }
       
        // 从 http 请求头中取出 token
        String token = httpServletRequest.getHeader("token");
       
        if (token == null) {
            throw new RuntimeException("无token，请重新登录");
        }
        
        // 验证 token
        JwtUtil.checkSign(token);
        
        // 验证通过后，这里测试取出JWT中存放的数据
        // 获取 token 中的 userId
        String userId = JwtUtil.getUserId(token);
        System.out.println("id:" + userId);
        
        // 获取 token 中的 其他数据
        Map info = JwtUtil.getInfo(token);
        info.forEach((k,v)->System.out.println(k+":"+v));

        
        return true;
    }

}

@Configuration
public class WebConfig implements WebMvcConfigurer {

    
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(jwtInterceptor())
                .addPathPatterns("")//要拦截的url
                .excludePathPatterns("/");//不是要拦截url
    }

    
    @Bean
    public JwtInterceptor jwtInterceptor() {
        return new JwtInterceptor();
    }
}

@Api(tags = "User")
@RestController
@RequestMapping("user")
public class UserController {

    @Autowired
    UserService service;
    
    //登录操作无需token
    //登录成功返回token
    @ApiOperation(value = "登录",notes = "传入用户名和密码")
    @PostMapping("/login")
    public Result login(String username,String password){
        Map info = new HashMap<>();
        User user = service.login(username, password);
        info.put("username", user.getUsername());
        info.put("realname", user.getRealname());
        info.put("role",user.getRole().getId());
        String token = JwtUtil.sign(Long.toString(user.getId()), info);
        return Result.success("token: "+token);
    }

    //删除操作在登陆操作之后
    //需要token
    @ApiOperation(value = "通过Id删除用户",notes = "传入要删除对象的Id")
    @ApiImplicitParams({
            @ApiImplicitParam(name = "token",value = "JWT",
                    dataType = "String",required = true,
                    paramType = "header"),
    })
    @DeleteMapping("/deleteUserById/{id}")
    public Result deleteUserById(@PathVariable Long id){
        service.deleteUserById(id);
        return Result.success("单个删除成功");
    }


}