jwt 进行用户认证

最新推荐文章于 2025-06-30 20:35:00 发布

原创最新推荐文章于 2025-06-30 20:35:00 发布 · 1.6k 阅读

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CC 4.0 BY-SA版权

文章标签：

#token #jwt

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总结

token的签名（生成token），解码（根据私钥和算法），判定token有效性、得到负载信息

好处

跨域（请求头中）

无状态化（不需要持久化）

依赖

<dependency>
  <groupId>com.auth0</groupId>
  <artifactId>java-jwt</artifactId>
</dependency>

生成token

public static String sign(String username, String userId) {
    try {
        Date date = new Date(System.currentTimeMillis() + EXPIRE_TIME); 
        Algorithm algorithm = Algorithm.HMAC256(TOKEN_SECRET); //根据私钥生成算法
        Map<String, Object> header = new HashMap<>(2);
        header.put("typ", "JWT");
        header.put("alg", "HS256");
        
        return JWT.create().
            withHeader(header).
            withClaim("loginName",  username).
            withClaim("userId", userId).
            withExpiresAt(date).sign(algorithm);
    } catch (UnsupportedEncodingException e) {
        return null;
    }
}


private static final long EXPIRE_TIME = 24 * 60 * 60 * 1000; //过期时间
 
private static final String TOKEN_SECRET = "f26e587c28064d0e855e72c0a6a0e618"; //私钥

认证

@GetMapping("/login")
@ResponseBody
public String login(User user) {
    String loginName = map.get("username");
    String password = map.get("password");

    boolean isSuccess = service.hasUserByUsernameAndPassword(username, password);
    if (isSuccess) {
        User user = userService.getUserByLoginName(loginName);
        if (user != null) {
            String token = JwtUtil.sign(user.getName(), user.getId());
            if (token != null)  return token;
        }
    }

    return "success";
}

拦截器配置（获取token，查看缓存中是否存在该token）

public class TokenInterceptor implements HandlerInterceptor {    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        String token = request.getHeader("access_token");
        if (token != null) {
            boolean result = JwtUtil.verify(token); 
            if (result) {
                return true;
            }
        }
    }
}

放行认证接口

<mvc:interceptors>
    <mvc:interceptor>
        <mvc:mapping path="/**" />
        <mvc:exclude-mapping path="/login/"/>
        <bean class="com.joe.interceptor.TokenInterceptor"></bean>
    </mvc:interceptor>
</mvc:interceptors>

验证token的有效性

public static boolean verify(String token) {
    try {
        Algorithm algorithm = Algorithm.HMAC256(TOKEN_SECRET);
        JWTVerifier verifier = JWT.require(algorithm).build();
        DecodedJWT jwt = verifier.verify(token);
        return true;
    } catch (Exception exception) {
        return false;
    }
}

获取负载信息

public static String getUsername(String token) {
    try {
        DecodedJWT jwt = JWT.decode(token);
        return jwt.getClaim("loginName").asString();
    } catch (JWTDecodeException e) {
        return null;
    }
}