用户登录时实现后台给前端传Token

1、导入依赖

<!--        token-->
        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.6.0</version>
       </dependency>
        <dependency>
            <groupId>com.auth0</groupId>
            <artifactId>java-jwt</artifactId>
            <version>3.4.0</version>
        </dependency>

2、加入工具类

package com.xiao.utils;

/**
 * @author ：xiaojinling
 * @date ：Created in 2021/9/9  17:14
 * @description ：
 * @version: 1.0
 */


import io.jsonwebtoken.Jwts;
import java.util.Date;

/**
 * JWT工具类
 */
public class JwtUtils {

    final static String base64EncodedSecretKey = "你的私钥";//私钥
    final static long TOKEN_EXP = 1000 * 60 * 10;//过期时间,测试使用十分钟，自己设置修改
    public static String getToken(String userName) {

        return Jwts.builder()

                .setSubject(userName)

                .claim("roles", "user")

                .setIssuedAt(new Date())

                .setExpiration(new Date(System.currentTimeMillis() + TOKEN_EXP)) /*过期时间*/
                .compact();
    }
}

3、Controller测试

package com.xiao.controller;

import com.xiao.Service.LoginService;
import com.xiao.Service.UserService;
import com.xiao.common.Result;
import com.xiao.pojo.User;
import com.xiao.utils.JwtUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;

@CrossOrigin
@Controller
@RestController//返回json字符串
@RequestMapping("/login")
public class LoginController {
    @Autowired(required = true)
    private LoginService loginService;
    @PostMapping("/user")
    public Result save(@RequestParam(value="username", required=false)String username,
                       @RequestParam(value="password",required=false)String password

    ){
        User user =new User();
        user.setUsername(username);
        user.setPassword(password);

        int i = loginService.loginUser(user);
        if(i==1) {
            String token = JwtUtils.getToken(user.getUsername());
            return Result.successLogin(i,token);
        }
        else{
            return Result.errorLogin(i);
        }
    }
}