JWT（JSON Web Token）

生成JWT

• 添加依赖

  <dependency>
      <groupId>com.auth0</groupId>
      <artifactId>java-jwt</artifactId>
      <version>3.10.3</version>
  </dependency>
  <dependency>
      <groupId>io.jsonwebtoken</groupId>
      <artifactId>jjwt</artifactId>
      <version>0.9.1</version>
  </dependency>
  

• 生成token

  String token = builder.setSubject(name)     //主题，就是token中携带的数据
      .setIssuedAt(new Date())            //设置token的生成时间
      .setId(user.getUserId() + "")       //设置用户id为token id
      .setClaims(hashMap)                 //map中可以存放用户的角色权限信息
      .setExpiration(new Date(System.currentTimeMillis() + 24 * 60 * 60 * 1000))
                                          //设置token过期时间
      .signWith(SignatureAlgorithm.ES256, "jyh9961")
      .compact();                         //设置加密方式和加密密码
  

• 解析token

  if(token == null){
      return new ResultVO(ResStatus.NO.getCode(), "请登录", null);
  }else {
      //验证token
      JwtParser parser = Jwts.parser();//解析器
      parser.setSigningKey("jyh9961");//解析token的密码必须与生成的一致
  
      try {
          Jws<Claims> claimsJws = parser.parseClaimsJws(token);
  
          Claims body = claimsJws.getBody();//获取token中的数据
  
          String subject = body.getSubject();//获取生成token设置的subject
          String v1 = body.get("key1",String.class);//获取生成token时储存的Claims的map中的值
  
          return new ResultVO(ResStatus.OK.getCode(), "success", null);
      } catch (ExpiredJwtException e) {
          return new ResultVO(ResStatus.NO.getCode(), "登录过期，请重新登录", null);
      } catch (UnsupportedJwtException e) {
          return new ResultVO(ResStatus.NO.getCode(), "Token不合法", null);
      } catch (Exception e) {
          return new ResultVO(ResStatus.NO.getCode(), "请重新登录", null);
      }
  }
  

• 拦截器校验Token

  • 创建拦截器

  public class CheckTokenInterceptor implements HandlerInterceptor {
  
      @Override
      public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
  
          String token = request.getParameter("token");
          if(token == null){
              ResultVO resultVO = new ResultVO(ResStatus.NO.getCode(), "请先登录", null);
              //提示先登录
              doResponse(response, resultVO);
          }else {
              try {
  
                  JwtParser parser = Jwts.parser();//解析器
                  parser.setSigningKey("jyh9961");//解析token的密码必须与生成的一致
                  Jws<Claims> claimsJws = parser.parseClaimsJws(token);
                  return true;
              } catch (ExpiredJwtException e) {
                  ResultVO resultVO = new ResultVO(ResStatus.NO.getCode(), "登录过期，请重新登录", null);
                  doResponse(response, resultVO);
              } catch (UnsupportedJwtException e) {
                  ResultVO resultVO = new ResultVO(ResStatus.NO.getCode(), "Token不合法，请重新登录", null);
                  doResponse(response, resultVO);
              } catch (Exception e) {
                  ResultVO resultVO = new ResultVO(ResStatus.NO.getCode(), "请先登录", null);
                  doResponse(response, resultVO);
              }
  
          }
          return false;
      }
  
      private void doResponse(HttpServletResponse response,ResultVO resultVO) throws IOException {
          response.setContentType("application/json");
          response.setCharacterEncoding("utf-8");
          PrintWriter out = response.getWriter();
          String s = new ObjectMapper().writeValueAsString(resultVO);
          out.print(s);
          out.flush();
          out.close();
      }
  

  • 配置拦截器

    新建拦截器配置类

@Configuration
public class InterceptorConfig implements WebMvcConfigurer {

    @Autowired
    private CheckTokenInterceptor checkTokenInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //创建拦截url集合
        ArrayList<String> PathPatternsList = new ArrayList<>();
        PathPatternsList.add("/shopcart/**");
        PathPatternsList.add("/orders/**");

        registry.addInterceptor(checkTokenInterceptor)
                //拦截的url
                .addPathPatterns(PathPatternsList)
                //放行的url
                .excludePathPatterns("/user/**");
    }
}