JWT请求流程
JWT验证登录的答题思路:
1、用户输入用户名和密码,POST请求去登陆,验证无误后,JWT创建token返回给客户端。
2、客户端将token存储在浏览器的cookie,前台发送请求要在Header携带token。
3、后台使用拦截器,拦截有@UserLoginToken的方法,校验token
4、服务器验证token正确后,返回数据给客户端。
代码实现过程如下:
封装JTW生成token和校验方法
public class JwtTokenUtil { //公用密钥-保存在服务端,客户端是不会知道密钥的,以防被攻击 public static String SECRET = "ThisIsASecret"; //生成Troke public static String createToken(String username) { //签发时间 //Date iatDate = new Date(); //过地时间 1分钟后过期 //Calendar nowTime = Calendar.getInstance(); //nowTime.add(Calendar.MINUTE, 1); //Date expiresDate = nowTime.getTime(); Map<String, Object> map = new HashMap(); map.put("alg", "HS256"); map.put("typ", "JWT"); String token = JWT.create() .withHeader(map) //.withClaim( "name","Free码生") //设置 载荷 Payload //.withClaim("age","12") //.withClaim( "org","测试") //.withExpiresAt(expiresDate)//设置过期时间,过期时间要大于签发时间 //.withIssuedAt(iatDate)//设置签发时间 .withAudience(username) //设置 载荷 签名的观众 .sign(Algorithm.HMAC256(SECRET));//加密 System.out.println("后台生成token:" + token); return token; } //校验TOKEN public static boolean verifyToken(String token) throws UnsupportedEncodingException{ JWTVerifier verifier = JWT.require(Algorithm.HMAC256(SECRET)).build(); try { verifier.verify(token); return true; } catch (Exception e){ return false; } } //获取Token信息 public static DecodedJWT getTokenInfo(String token) throws UnsupportedEncodingException{ JWTVerifier verifier = JWT.require(Algorithm.HMAC256(SECRET)).build(); try{ return verifier.verify(token); } catch(Exception e){ throw new RuntimeException(e); } } }
新建自定义注解:@UserLoginToken
@Target({ElementType.METHOD, ElementType.TYPE}) @Retention(RetentionPolicy.RUNTIME) public @interface UserLoginToken { boolean required() default true; }
使用拦截器拦截有@UserLoginToken注解的方法
@Configuration public class InterceptorConfig implements WebMvcConfigurer { @Override public void addInterceptors(InterceptorRegistry registry) { registry.addInterceptor(authenticationInterceptor()) .addPathPatterns("/**"); // 拦截所有请求,通过判断是否有 @LoginRequired 注解 决定是否需要登录 } @Bean public AuthenticationInterceptor authenticationInterceptor() { return new AuthenticationInterceptor(); } }
public class AuthenticationInterceptor implements HandlerInterceptor { @Autowired UserService userService; @Override public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object object) throws Exception { String token = httpServletRequest.getHeader("token");// 从 http 请求头中取出 token // 如果不是映射到方法直接通过 if(!(object instanceof HandlerMethod)){ return true; } HandlerMethod handlerMethod=(HandlerMethod)object; Method method=handlerMethod.getMethod(); //检查是否有passtoken注释,有则跳过认证 if (method.isAnnotationPresent(PassToken.class)) { PassToken passToken = method.getAnnotation(PassToken.class); if (passToken.required()) { return true; } } //检查有没有需要用户权限的注解 if (method.isAnnotationPresent(UserLoginToken.class)) { UserLoginToken userLoginToken = method.getAnnotation(UserLoginToken.class); if (userLoginToken.required()) { // 执行认证 if (token == null) { throw new RuntimeException("无token,请重新登录"); } // 验证 token if(JwtTokenUtil.verifyToken(token)){ return true; }else { throw new RuntimeException("401"); } } } return true; } @Override public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception { } @Override public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception { } }
登录:
在Controller上登录方法不用添加@UserLoginToken自定义注解,其余获取后台数据方法加上@UserLoginToken自定义注解,目的验证token是否有效,是则返回数据,否则提示401无权限。
测试:
@Controller @RequestMapping(path = "/api") public class IndexController { private String prefix = "index/"; @GetMapping("/index") public String index() { return prefix + "index"; } @UserLoginToken @PostMapping("/test") @ResponseBody public Object test(){ Map<String,Object> map = new HashMap<>(); map.put("code","200"); map.put("message","你已通过验证了"); return map; } }
HTTP请求带上登陆成功后生成token,返回成功:
HTTP请求带上无效token或不带token,返回失败: