生成JWT_jwt生成

学习来源：b站https://www.bilibili.com/video/BV1rp4y1t7Ks?p=1

一.基本使用

1.引入依赖

<!-- 生成方式 -->
        <dependency>
            <groupId>com.auth0</groupId>
            <artifactId>java-jwt</artifactId>
            <version>3.19.2</version>
        </dependency>
        <!-- 加密算法 -->
        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.9.1</version>
        </dependency>
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2.生成token

Service

  @Override
    public ResultVO checkLogin(String name, String password) {
        Example example = new Example(Users.class);
        Example.Criteria criteria = example.createCriteria();
        criteria.andEqualTo("username", name);
        List<Users> users = usersMapper.selectByExample(example);

        if (users.size() == 0) {
            return new ResultVO(ResultStatus.NO, "登录失败，用户名不存在！", null);

        }else {
            String md5Pwd = MD5Utils.md5(password);
            if (md5Pwd.equals(users.get(0).getPassword())){
                //如果登录验证成功,则需要生成令牌token(token就是按照特定规则生成的字符串)

                //使用jwt规则生成token字符串,支持链式调用
                JwtBuilder builder = Jwts.builder();
                HashMap<String,Object> map = new HashMap<>();
                map.put("key1","value1");
                map.put("key2","value2");
                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(users.get(0).getUserId() + "") //设置用户id为token id,需要字符串类型
                        .setClaims(map)             //map中可以存放用户的角色权限信息
                        .setExpiration(new Date(System.currentTimeMillis() + 24 * 60 * 60 * 1000))  //设置过期时间,拿到系统时间，再往后推迟一天
                        .signWith(SignatureAlgorithm.HS256, "Mordle") //设置加密方式和加密密码
                        .compact(); //设置为字符串 成为token
                return new ResultVO(ResultStatus.OK, token,users.get(0));
            }else {
                return new ResultVO(ResultStatus.NO, "登录失败,密码错误！", null);
            }
        }

    }
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3.存储token到cookie

设置cookie跳转

login.html

doSubmit:function(){
						if(vm.isRight){
							var url=baseUrl+"user/login";
							axios.get(url,{
								params:{
									username:vm.username,
									password:vm.password
								}
							})
							.then((res)=>{
								//res.data才表示返回的数据
								var vo=res.data;
								if(vo.code==10000){
									//如果登录成功,就把token存到cookie中
									setCookieValue("token",vo.msg);
								window.location.href="index.html";
								}else{
									vm.tips="登录失败,账号或密码错误";
								}
							});
						}else{
							vm.tips="请正确输入账号和密码！";
						}
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4.解析token

Controller

public class ShopCartController {

    @ApiOperation("购物车列表接口")
    @ApiImplicitParam(dataType = "string",name = "token",value = "用户令牌",required = true)
    @GetMapping("/list")
    public ResultVO listCarts(String token){
        //1.获取token
        if (token==null){
            return new ResultVO(ResultStatus.NO,"请先登录",null);
        }else {
            2.校验token,对token进行解码
            JwtParser parser = Jwts.parser();
            parser.setSigningKey("Mordle"); //解析token的SignKey必须和生成token时的密码一致


            //如果token正确(密码正确,有效期内)则正常执行,否则抛出异常
            try {
                //token校验成功
                Jws<Claims> claimsJws = parser.parseClaimsJws(token);
                Claims body = claimsJws.getBody();//获取token中用户数据
                String v1 = body.get("key1", String.class);//获取生成token时存储的map中的值
                String subject = body.getSubject();//获取生成token设置的subject           
                return new ResultVO(ResultStatus.OK,"success",null);
            }catch (Exception exception){
                return new ResultVO(ResultStatus.NO,"登录过期,请先登录！",null);
            }

        }



    }
}

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5.获取token
权限页面

<script type="text/javascript">
		var baseUrl="http://localhost:8080/";
		var vm=new Vue({
			el:'#container',
			data:{
				token:"",
				shopcarts:[]
			},
			created:function(){
				//当进入购物车页面时候,就要查询购物城列表(访问购物车列表接口)
				this.token=getCookieValue("token");
				var url=baseUrl+"shopcart/list";
				axios.get(url,{params:{
					token:this.token
					
				}}).then((res)=>{
					var vo=res.data;
					console.log(vo);
				});
			}
		});
		</script>
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二.拦截器校验token

1.生成拦截器

就是把controller里的进行封装

package com.mordle.mall.interceptor;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.mordle.mall.vo.ResultStatus;
import com.mordle.mall.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;

/*拦截器*/
@Component
public class CheckTokenInterceptor implements HandlerInterceptor {
    /*前置拦截*/
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        String token=request.getParameter("token");
        
        if(token==null){
       	   ResultVO resultVO = new ResultVO(ResultStatus.NO, "请先登录", null);
           doResponse(response,resultVO);

        }else{
            try {
                2.校验token,对token进行解码
                JwtParser parser = Jwts.parser();
                parser.setSigningKey("Mordle"); //解析token的SignKey必须和生成token时的密码一致
                //如果token正确(密码正确,有效期内)则正常执行,否则抛出异常
                //token校验成功
                Jws<Claims> claimsJws = parser.parseClaimsJws(token);
                return true;
            }catch (ExpiredJwtException e){
                ResultVO vo = new ResultVO(ResultStatus.NO, "登录过期,请重新登录！", null);
                doResponse(response,vo);
            }catch (UnsupportedJwtException exception){
                ResultVO vo =  new ResultVO(ResultStatus.NO,"Token不合法,请自重！",null);
                doResponse(response,vo);
            }catch (Exception exception){
                ResultVO vo =   new ResultVO(ResultStatus.NO,"请重新登录！",null);
                doResponse(response,vo);
            }

        }
        return false;
    }
    private void doResponse(HttpServletResponse response,ResultVO resultVO) throws IOException {
        //提示请先登录
        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();
    }

}

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2.配置拦截器

@Configuration
public class InterceptorConfig implements WebMvcConfigurer {
    @Autowired
    private CheckTokenInterceptor checkTokenInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(checkTokenInterceptor)
                .addPathPatterns("/shopcart/**") //拦截受限资源
                .addPathPatterns("/orders/**")
                .excludePathPatterns("/user/**"); //除了user开头
    }
}

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3.控制器

@RestController
@RequestMapping("/shopcart")
@CrossOrigin
@Api(value = "提供购物车相关接口",tags = "购物车管理")
public class ShopCartController {

    @ApiOperation("购物车列表接口")
    @ApiImplicitParam(dataType = "string",name = "token",value = "用户令牌",required = true)
    @GetMapping("/list")
    public ResultVO listCarts(String token){
          return new ResultVO(ResultStatus.OK,"success",null);

    }
}

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3.请求头传递token

前端访问受限资源必须携带token进行请求，习惯性用header传递

并且把后端接收方式改了