Spring Boot 集成JWT实现前后端认证的示例代码

{
    "alg": "HS256",
    "typ": "JWT"
}

{
    //默认字段
    "sub":"主题123",
    //自定义字段
    "name":"java",
    "isAdmin":"true",
    "loginTime":"2021-12-05 12:00:03"
}

<dependency>
        <groupId>io.jsonwebtoken</groupId>
        <artifactId>jjwt</artifactId>
        <version>0.9.1</version>
  </dependency>

public class JwtUtil
{
//创建jwt
public static String createJWT(String subject, String issue, Object claim,
            long ttlMillis)
    {
       //当前时间
        long nowMillis = System.currentTimeMillis();
        //过期时间
        long expireMillis = nowMillis + ttlMillis;
        String result = Jwts.builder()
                .setSubject(subject) //设置主题
                .setIssuer(issue) //发行者
                .setId(issue)//jwtID
                .setExpiration(new Date(expireMillis)) //设置过期日期
                .claim("user", claim)//主题，可以包含用户信息
                .signWith(getSignatureAlgorithm(), getSignedKey())//加密算法
                .compressWith(CompressionCodecs.DEFLATE).compact();//对载荷进行压缩

        return result;
    }
    
    // 解析jwt
    public static Jws<Claims> pareseJWT(String jwt)
    {
        Jws<Claims> claims;
        try
        {
            claims = Jwts.parser().setSigningKey(getSignedKey())
                    .parseClaimsJws(jwt);
        }
        catch (Exception ex)
        {
            claims = null;
        }
        return claims;
    }

   //获取主题信息
    public static Claims getClaims(String jwt)
    {
        Claims claims;
        try
        {
            claims = Jwts.parser().setSigningKey(getSignedKey())
                    .parseClaimsJws(jwt).getBody();
        }
        catch (Exception ex)
        {
            claims = null;
        }
        return claims;
    }
  }
  
   /**
     * 获取密钥
     * 
     * @return Key
     */
    private static Key getSignedKey()
    {
        byte[] apiKeySecretBytes = DatatypeConverter
                .parseBase64Binary(getAuthKey());
        Key signingKey = new SecretKeySpec(apiKeySecretBytes,
                getSignatureAlgorithm().getJcaName());
        return signingKey;
    }
    
    private static SignatureAlgorithm getSignatureAlgorithm()
    {
        return SignatureAlgorithm.HS256;
    }
  
  //获取密钥,可以动态配置
  public static String getAuthKey()
  {
        String auth = "123@#1234";
  }

 Component
public class TokenInterceptor extends HandlerInterceptorAdapter
{
    public static Log logger = LogManager.getLogger(TokenInterceptor.class);

    @Override
    public boolean preHandle(HttpServletRequest request,
            HttpServletResponse response, Object handler) throws Exception
    {
        String uri = request.getRequestURI();
        logger.info("start TokenInterceptor preHandle.." + uri);
         
		//需要过滤特殊请求
        if (SystemUtil.isFree(uri) || SystemUtil.isProtected(uri))
        {
            return true;
        }
        
		
        String metohd=request.getMethod().toString();
        logger.info("TokenInterceptor request method:"+metohd);
        //options 方法需要过滤
        if("OPTIONS".equals(metohd))
        {
            return true;   
        }
        
		//是否开启token认证
        boolean flag = SystemUtil.getVerifyToken();
        ResponseResult result = new ResponseResult();
		//从请求的head信息中获取token
        String token = request.getHeader("X-Token");

        if (flag)
        {
            if(StringUtils.isEmpty(token))
            {
                token=request.getParameter("X-Token");    
            }
            // token不存在
            if (StringUtils.isEmpty(token))
            {
                result.setCode(ResultCode.NEED_AUTH.getCode());
                result.setMsg(ResultCode.NEED_AUTH.getMsg());
                WebUtil.writeJson(result, response);
                return false;
            }
            else
            {
                Claims claims = JwtUtil.getClaims(token);
                String subject = "";
                if (claims != null)
                {
                    subject = claims.getSubject();
                    // 验证主题
                    if (StringUtils.isEmpty(subject))
                    {
                        result.setCode(ResultCode.INVALID_TOKEN.getCode());
                        result.setMsg(ResultCode.INVALID_TOKEN.getMsg());
                        WebUtil.writeJson(result, response);
                        return false;
                    }								
                }
                else
                {
                    result.setCode(ResultCode.INVALID_TOKEN.getCode());
                    result.setMsg(ResultCode.INVALID_TOKEN.getMsg());
                    WebUtil.writeJson(result, response);
                    return false;
                }
            }
        }
        return true;
    }

}

@Configuration
public class WebConfig implements WebMvcConfigurer
{
    @Resource
    private TokenInterceptor tokenInterceptor;

    public void addInterceptors(InterceptorRegistry registry)
    {
        registry.addInterceptor(tokenInterceptor).addPathPatterns("/**");
    }
 }

@RequestMapping("login")
public Result login(HttpServletResponse response)
{
    Map<String, Object> map = new HashMap<>();
    //
    Result result = loginAuth(user);
    int code = result.getCode();
            //登录认证成功
    if (code ==ResultCode.SUCCESS)
    {
        //默认为7天
        Long ttlMillis = 7*1000 * 60 * 60 * 24;
        //过期时间
        long expreTime = System.currentTimeMillis() + ttlMillis;
        String tokenKey = UUID.randomUUID().toString();
        String tokenId = JwtUtil.createJWT(user.getUserId(), tokenKey,
                user.getPassword(), expreTime);                   
        map.put("expreTime", expreTime);				
        map.put("tokenId", tokenId);           
    }
    else
    {
        logger.error("login error:" +FastJsonUtil.toJSONString(result));
    }
    return result;
}