Json Web Token实战之封装通用方法

• 加入相关依赖

    <!-- JWT相关 --><dependency><groupId>io.jsonwebtoken</groupId><artifactId>jjwt</artifactId><version>0.7.0</version></dependency>

• 封装生产token方法

/*** 根据用户信息，生成令牌* @param user* @return*/public static String geneJsonWebToken(User user){String token = Jwts.builder().setSubject(SUBJECT).claim("head_img",user.getHeadImg()).claim("id",user.getId()).claim("name",user.getName()).setIssuedAt(new Date()).setExpiration(new Date(System.currentTimeMillis() + EXPIRE)).signWith(SignatureAlgorithm.HS256,SECRET).compact();token = TOKEN_PREFIX + token;return token;}

• 封装校验token方法

/*** 校验token的方法* @param token* @return*/public static Claims checkJWT(String token){try{final  Claims claims = Jwts.parser().setSigningKey(SECRET).parseClaimsJws(token.replace(TOKEN_PREFIX,"")).getBody();return claims;}catch (Exception e){return null;}}

• 配置连接器登录校验成功放行

 /*** 进入到controller之前的方法* @param request* @param response* @param handler* @return* @throws Exception*/
public class LoginInterceptor implements HandlerInterceptor {/***   进入controller之前分方法* @param request* @param response* @param handler* @return* @throws Exception*/@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {try {String accesToken = request.getHeader("token");if (accesToken == null ){accesToken = request.getParameter("token");}if (StringUtils.isNotBlank(accesToken)){Claims claims = JWTUtils.checkJWT(accesToken);if (claims == null ){//告诉登录过期 ，重新登录sendJsonMessage(response, JsonData.buildError("登录失败，请重新登录"));return false;}Integer id = (Integer)claims.get("id");String name = (String)claims.get("name");request.setAttribute("user_id",id);request.setAttribute("name",name);return  true;}}catch (Exception e){//登录失败e.printStackTrace();}sendJsonMessage(response, JsonData.buildError("登录失败，请重新登录"));return false;}public  static  void sendJsonMessage(HttpServletResponse response,Object obj){try {ObjectMapper objectMapper = new ObjectMapper();response.setContentType("application/json; charset=utf-8");PrintWriter writer = response.getWriter();writer.print(objectMapper.writeValueAsString(obj));writer.close();response.flushBuffer();}catch (Exception e){}}/***   进入controller* @param request* @param response* @param handler* @return* @throws Exception*/@Overridepublic void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {}/***   进入controller* @param request* @param response* @param handler* @return* @throws Exception*/@Overridepublic void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {}
}}

• 登录不成功返回json数据

 /*** 响应json数据给前端* @param response* @param obj*/
public static void sendJsonMessage(HttpServletResponse response, Object obj){try{ObjectMapper objectMapper = new ObjectMapper();response.setContentType("application/json; charset=utf-8");PrintWriter writer = response.getWriter();writer.print(objectMapper.writeValueAsString(obj));writer.close();response.flushBuffer();}catch (Exception e){e.printStackTrace();}}

• 返回值对象

public class JsonData {//状态吗   0 成功   1处理中    -1失败private  Integer code;//业务数据private Object data;//信息描述private String  msg;public JsonData(){}public JsonData(Integer code, Object data, String msg){this.code = code;this.data = data;this.msg = msg;}//成功public  static  JsonData buildSuccess(){return  new JsonData(0,null,null);}//成功需要数据public  static  JsonData buildSuccess(Object data){return  new JsonData(0,data,null);}//失败public  static  JsonData buildError(String msg){return  new JsonData(-1,null,msg);}//失败public  static  JsonData buildError(Integer code,String msg){return  new JsonData(code,null,msg);}public Integer getCode() {return code;}public void setCode(Integer code) {this.code = code;}public Object getData() {return data;}public void setData(Object data) {this.data = data;}public String getMsg() {return msg;}public void setMsg(String msg) {this.msg = msg;}
}