基于jwt的用户鉴权：拦截器概述

基于拦截器的token与鉴权

如果我们每个方法都去写一段代码，冗余度太高，不利于维护，那如何做使我们的代码看起来更清爽呢？我们可以将这段代码放入拦截器去实现

Spring中的拦截器

Spring为我们提供了org.springframework.web.servlet.handler.HandlerInterceptorAdapter这个适配器，继承此类，可以非常方便的实现自己的拦截器。他有三个方法：分别实现预处理、后处理（调用了Service并返回ModelAndView，但未进行页面渲染）、返回处理（已经渲染了页面）

1.在preHandle中，可以进行编码、安全控制等处理； 2.在postHandle中，有机会修改ModelAndView； 3.在afterCompletion中，可以根据ex是否为null判断是否发生了异常，进行日志记录。

package com.learn.common.interceptor;

import com.learn.common.entity.ResultCode;
import com.learn.common.exception.CommonException;
import com.learn.common.utils.JwtUtils;
import io.jsonwebtoken.Claims;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 自定义拦截器
 *      继承HandlerInterceptorAdapter
 *
 *      preHandle:进入到控制器方法之前执行的内容
 *          boolean：
 *              true：可以继续执行控制器方法
 *              false：拦截
 *      posthandler：执行控制器方法之后执行的内容
 *      afterCompletion：响应结束之前执行的内容
 *
 * 1.简化获取token数据的代码编写
 *      统一的用户权限校验（是否登录）
 * 2.判断用户是否具有当前访问接口的权限
 *
 */
@Component
public class JwtInterceptor extends HandlerInterceptorAdapter {

    /**
     * 简化获取token数据的代码编写（判断是否登录）
     *  1.通过request获取请求token信息
     *  2.从token中解析获取claims
     *  3.将claims绑定到request域中
     */

    @Autowired
    private JwtUtils jwtUtils;

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        // 1.通过request获取请求token信息
        String authorization = request.getHeader("Authorization");
        //判断请求头信息是否为空，或者是否已Bearer开头
        if(!StringUtils.isEmpty(authorization) && authorization.startsWith("Bearer")) {
            //获取token数据
            String token = authorization.replace("Bearer ","");
            //解析token获取claims
            Claims claims = jwtUtils.parseJwt(token);
            if(claims != null) {
                //通过claims获取到当前用户的可访问API权限字符串
                String apis = (String) claims.get("apis");  //api-user-delete,api-user-update
                //通过handler
                HandlerMethod h = (HandlerMethod) handler;
                //获取接口上的reqeustmapping注解
                RequestMapping annotation = h.getMethodAnnotation(RequestMapping.class);
                //获取当前请求接口中的name属性
                String name = annotation.name();
                //判断当前用户是否具有响应的请求权限
                if(apis.contains(name)) {
                    request.setAttribute("user_claims",claims);
                    return true;
                }else {
                    throw new CommonException(ResultCode.UNAUTHORISE);
                }
            }
        }
        throw new CommonException(ResultCode.UNAUTHENTICATED);
    }
}

package com.learn.system.controller;

import com.learn.common.controller.BaseController;
import com.learn.common.entity.PageResult;
import com.learn.common.entity.Result;
import com.learn.common.entity.ResultCode;

import com.learn.common.exception.CommonException;
import com.learn.common.utils.JwtUtils;
import com.learn.common.utils.PermissionConstants;
import com.learn.domain.system.Permission;
import com.learn.domain.system.Role;
import com.learn.domain.system.response.ProfileResult;
import com.learn.domain.system.User;
import com.learn.domain.system.response.UserResult;
import com.learn.system.service.PermissionService;
import com.learn.system.service.RoleService;
import com.learn.system.service.UserService;
import io.jsonwebtoken.Claims;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.*;

import javax.servlet.http.HttpServletRequest;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

//1.解决跨域
@CrossOrigin
//2.声明restContoller
@RestController
//3.设置父路径
@RequestMapping(value="/sys")
public class UserController extends BaseController {

    @Autowired
    private UserService userService;

    @Autowired
    private PermissionService permissionService;

    @Autowired
    private JwtUtils jwtUtils;

    /**
     * 分配角色
     */
    @RequestMapping(value = "/user/assignRoles", method = RequestMethod.PUT)
    public Result assignRoles(@RequestBody Map<String,Object> map) {
        //1.获取被分配的用户id
        String userId = (String) map.get("id");
        //2.获取到角色的id列表
        List<String> roleIds = (List<String>) map.get("roleIds");
        //3.调用service完成角色分配
        userService.assignRoles(userId,roleIds);
        return new Result(ResultCode.SUCCESS);
    }

    /**
     * 保存
     */
    @RequestMapping(value = "/user", method = RequestMethod.POST)
    public Result save(@RequestBody User user) {
        //1.设置保存的企业id
        user.setCompanyId(companyId);
        user.setCompanyName(companyName);
        //2.调用service完成保存企业
        userService.save(user);
        //3.构造返回结果
        return new Result(ResultCode.SUCCESS);
    }

    /**
     * 查询企业的部门列表
     * 指定企业id
     */
    @RequestMapping(value = "/user", method = RequestMethod.GET)
    public Result findAll(int page, int size, @RequestParam Map map) {
        //1.获取当前的企业id
        map.put("companyId",companyId);
        //2.完成查询
        Page<User> pageUser = userService.findAll(map,page,size);
        //3.构造返回结果
        PageResult pageResult = new PageResult(pageUser.getTotalElements(),pageUser.getContent());
        return new Result(ResultCode.SUCCESS, pageResult);
    }

    /**
     * 根据ID查询user
     */
    @RequestMapping(value = "/user/{id}", method = RequestMethod.GET)
    public Result findById(@PathVariable(value = "id") String id) {
        // 添加 roleIds (用户已经具有的角色id数组)
        User user = userService.findById(id);
        UserResult userResult = new UserResult(user);
        return new Result(ResultCode.SUCCESS, userResult);
    }

    /**
     * 修改User
     */
    @RequestMapping(value = "/user/{id}", method = RequestMethod.PUT)
    public Result update(@PathVariable(value = "id") String id, @RequestBody User user) {
        //1.设置修改的部门id
        user.setId(id);
        //2.调用service更新
        userService.update(user);
        return new Result(ResultCode.SUCCESS);
    }

    /**
     * 根据id删除
     */
    @RequestMapping(value = "/user/{id}", method = RequestMethod.DELETE,name = "API-USER-DELETE")
    public Result delete(@PathVariable(value = "id") String id) {
        userService.deleteById(id);
        return new Result(ResultCode.SUCCESS);
    }


    /**
     * 用户登录
     *  1.通过service根据mobile查询用户
     *  2.比较password
     *  3.生成jwt信息
     *
     */
    @RequestMapping(value="/login",method = RequestMethod.POST)
    public Result login(@RequestBody Map<String,String> loginMap) {
        String mobile = loginMap.get("mobile");
        String password = loginMap.get("password");
        User user = userService.findByMobile(mobile);
        //登录失败
        if(user == null || !user.getPassword().equals(password)) {
            return new Result(ResultCode.MOBILEORPASSWORDERROR);
        }else {
            //登录成功
            //api权限字符串
            StringBuilder sb = new StringBuilder();
            //获取到所有的可访问API权限
            for (Role role : user.getRoles()) {
                for (Permission perm : role.getPermissions()) {
                    if(perm.getType() == PermissionConstants.PERMISSION_API) {
                        sb.append(perm.getCode()).append(",");
                    }
                }
            }
            Map<String,Object> map = new HashMap<>();
            map.put("apis",sb.toString());//可访问的api权限字符串
            map.put("companyId",user.getCompanyId());
            map.put("companyName",user.getCompanyName());
            String token = jwtUtils.createJwt(user.getId(), user.getUsername(), map);
            return new Result(ResultCode.SUCCESS,token);
        }
    }


    /**
     * 用户登录成功之后，获取用户信息
     *      1.获取用户id
     *      2.根据用户id查询用户
     *      3.构建返回值对象
     *      4.响应
     */
    @RequestMapping(value="/profile",method = RequestMethod.POST)
    public Result profile(HttpServletRequest request) throws Exception {

        String userid = claims.getId();
        //获取用户信息
        User user = userService.findById(userid);
        //根据不同的用户级别获取用户权限

        ProfileResult result = null;

        if("user".equals(user.getLevel())) {
            result = new ProfileResult(user);
        }else {
            Map map = new HashMap();
            if("coAdmin".equals(user.getLevel())) {
                map.put("enVisible","1");
            }
            List<Permission> list = permissionService.findAll(map);
            result = new ProfileResult(user,list);
        }
        return new Result(ResultCode.SUCCESS,result);
    }
}

package com.learn.common.controller;

import io.jsonwebtoken.Claims;
import org.springframework.web.bind.annotation.ModelAttribute;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class BaseController {

    protected HttpServletRequest request;
    protected HttpServletResponse response;
    protected String companyId;
    protected String companyName;
    protected Claims claims;

    @ModelAttribute
    public void setResAnReq(HttpServletRequest request,HttpServletResponse response) {
        this.request = request;
        this.response = response;

        Object obj = request.getAttribute("user_claims");

        if(obj != null) {
            this.claims = (Claims) obj;
            this.companyId = (String)claims.get("companyId");
            this.companyName = (String)claims.get("companyName");
        }
    }

}

 

来源：CSDN

作者：Leon_Jinhai_Sun

链接：https://blog.csdn.net/Leon_Jinhai_Sun/article/details/103791082