Token生成方案-JWT_java jwt token方案

}

##### Payload


Payload部分包含了一系列声明，其中一些是JWT的注册声明，而其他则是公开声明或私有声明。声明包含了关于用户和其他一些元数据的信息。

{
“sub”: “1234567890”,
“name”: “John Doe”,
“iat”: 1516239022
}

##### Signature


Signature部分对前两部分进行签名，确保Token在传输过程中没有被篡改。


![](https://img-blog.csdnimg.cn/direct/9e44757eeee840cb879648c30c505265.png)


#### 使用JWT生成Token



##### 引入依赖

io.jsonwebtoken jjwt 0.9.0 ```

创建JwtUtil工具类

package com.exmple.utils;

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.JwtBuilder;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;

import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;
import java.util.Date;
import java.util.UUID;

/**
 * JWT工具类
 */
public class JwtUtil {
    //有效期为
    public static final Long JWT_TTL = 60 * 60 * 1000L;// 60 * 60 *1000 一个小时
    //设置秘钥明文
    public static final String JWT_KEY = "奇遇少年";

    /**
     * 创建token
     *
     * @param id
     * @param subject
     * @param ttlMillis
     * @return
     */
    public static String createJWT(String id, String subject, Long ttlMillis) {
        SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.HS256;
        long nowMillis = System.currentTimeMillis();
        Date now = new Date(nowMillis);
        if (ttlMillis == null) {
            ttlMillis = JwtUtil.JWT_TTL;
        }
        long expMillis = nowMillis + ttlMillis;
        Date expDate = new Date(expMillis);
        SecretKey secretKey = generalKey();
        JwtBuilder builder = Jwts.builder()
                .setId(id) //唯一的ID
                .setSubject(subject) // 主题 可以是JSON数据
                .setIssuer("yu") // 签发者
                .setIssuedAt(now) // 签发时间
                .signWith(signatureAlgorithm, secretKey) //使用HS256对称加密算法签 名, 第二个参数为秘钥
                .setExpiration(expDate);// 设置过期时间
        return builder.compact();
    }

    /**
     * 生成加密后的秘钥 secretKey
     *
     * @return
     */
    public static SecretKey generalKey() {
        byte[] encodedKey = Base64.getDecoder().decode(JwtUtil.JWT_KEY);
        SecretKey key = new SecretKeySpec(encodedKey, 0, encodedKey.length, "AES");
        return key;
    }

    /**
     * 解析
     *
     * @param jwt
     * @return
     * @throws Exception
     */
    public static Claims parseJWT(String jwt) throws Exception {
        SecretKey secretKey = generalKey();
        return Jwts.parser()
                .setSigningKey(secretKey)
                .parseClaimsJws(jwt)
                .getBody();
    }
}

数据准备

CREATE TABLE `user` (
  `id` int(10) NOT NULL AUTO_INCREMENT,
  `name` varchar(20) DEFAULT NULL,
  `pwd` varchar(20) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8

实体类

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User implements Serializable {
    private Integer id;
    private String name;
    private String pwd;
}

UserController

package com.exmple.controller;

import com.exmple.pojo.User;
import com.exmple.result.ResponseResult;
import com.exmple.service.UserService;
import com.exmple.utils.JwtUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.HashMap;
import java.util.Map;
import java.util.UUID;

@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    private UserService userService;

    @PostMapping("/login")
    public ResponseResult login(@RequestBody User user) {
//校验用户名密码是否正确
        User loginUser = userService.login(user);
        Map<String, Object> map;
        if (loginUser != null) {

            //如果正确 生成token返回
            map = new HashMap<>();
            String token = JwtUtil.createJWT(UUID.randomUUID().toString(),
                    String.valueOf(loginUser.getId()), null);
            map.put("token", token);
        } else {
//如果不正确 给出相应的提示
            return ResponseResult.error("用户名或密码错误，请重新登录");
        }
        return  ResponseResult.success(map);
    }
}

Service

package com.exmple.service.impl;

import com.exmple.mapper.UserMapper;
import com.exmple.pojo.User;
import com.exmple.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper UserMapper;
    @Override
    public User login(User user) {
        User loginUser = UserMapper.login(user);
        return loginUser;
    }
}

dao

package com.exmple.mapper;

import com.exmple.pojo.User;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface UserMapper {
    User login(User user);
}