jwt生成token及拦截器解析token

        <!--jwt加密-->
        <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
                JwtBuilder builder = Jwts.builder();
                String token = builder.setSubject(username)   //主题，就是token中携带的数据
                        .setIssuedAt(new Date())  //创建时间
                        .setId(users.get(0).getUserId() + "")  //设置用户id为token id
                        .setClaims(new HashMap() {{

                        }}) //map可以存放用户角色 权限信息
                        .setExpiration(new Date(System.currentTimeMillis() + 24 * 60 * 60 * 1000)) //设置过期时间
                        .signWith(SignatureAlgorithm.HS256, "caowei666") //设置加密算法 和 密码
                        .compact();

import com.fasterxml.jackson.databind.ObjectMapper;
import com.qfedu.fmmall.vo.ResultVo;
import io.jsonwebtoken.*;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;

@Component
public class CheckTokenInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //前端header中如果有自定义值则会执行预检请求
        if(request.getMethod().equalsIgnoreCase("options")) {
            return true;
        }
        String token = request.getHeader("token");
        if(token == null) {
            //提示请先登录
            ResultVo resultVo = new ResultVo(401, "请先登录！", null);
            doResponse(response, resultVo);
            return false;
        }else {
            try {
                //解析token
                JwtParser parser = Jwts.parser();
                parser.setSigningKey("caowei666");

                //如果token正确（密码正确，有效期内）则不会报异常
                Jws<Claims> claimsJws = parser.parseClaimsJws(token);
                return true;

            }catch (ExpiredJwtException e) {
                ResultVo resultVo = new ResultVo(401, "登录过期！", null);
                doResponse(response, resultVo);
            }catch (UnsupportedJwtException e){
                ResultVo resultVo = new ResultVo(401, "token不合法！", null);
                doResponse(response, resultVo);

            }catch (Exception e){
                ResultVo resultVo = new ResultVo(401, "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 writer = response.getWriter();
        String s = new ObjectMapper().writeValueAsString(resultVo);
        writer.print(s);
        writer.flush();
        writer.close();
    }
}

@Configuration
public class InterceptorConfig implements WebMvcConfigurer {

    @Autowired
    private CheckTokenInterceptor checkTokenInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(checkTokenInterceptor)
                .addPathPatterns("/**")
                .excludePathPatterns("/user/**");
    }
}