SpringBoot用户登录拦截器实现

1、实现接口：HandlerInterceptor，重写 preHandle方法。

import com.google.gson.Gson;
import io.jsonwebtoken.Claims;
import net.xdclass.xdvidio.domain.JsonData;
import net.xdclass.xdvidio.utils.JwtUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;

/**
 * @Author Pandas
 * @Date 2020/4/10 23:22
 * @Version 1.0
 * @Description 描述这个类是做什么的
 */
public class LoginInterceoter implements HandlerInterceptor {

    private static final Gson gson=new Gson();
    /**
     * 进入controller之前进行拦截
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        String token =request.getHeader("token");
        if(token==null){
            token=request.getParameter("token");
        }
        if(token!=null){//解密
           Claims claims= JwtUtils.checkJWT(token);
           Integer userId=(Integer) claims.get("id");
           String name=(String)claims.get("name");

           request.setAttribute("user_id",userId);
           request.setAttribute("name",name);

           return  true;
        }
        sendJsonMessage(response, JsonData.buildError("请登录"));
        return false;
    }

    /**
     * 响应数据给前端
     * @param response
     * @param object
     */
    public static void sendJsonMessage(HttpServletResponse response,Object object)throws IOException{
        response.setContentType("application/json;charset=utf-8");

            PrintWriter writer=response.getWriter();
            writer.print(gson.toJson(object));
            writer.close();
            response.flushBuffer();
    }
}

2、配置拦截器

import net.xdclass.xdvidio.interceoter.LoginInterceoter;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

/**
 * @Author Pandas
 * @Date 2020/4/10 23:42
 * @Version 1.0
 * @Description 拦截器配置类
 */
@Configuration
public class IntercepterConfig implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LoginInterceoter()).addPathPatterns("/user/api/v1/*/**");
        WebMvcConfigurer.super.addInterceptors(registry);
    }
}