SpringBoot开发（2）——登录

<!--jwt依赖-->
<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt</artifactId>
    <version>0.9.1</version>
</dependency>

 <!--解决jdk版本过高，jwt有问题-->
<dependency>
    <groupId>javax.xml.bind</groupId>
    <artifactId>jaxb-api</artifactId>
    <version>2.3.1</version>
</dependency>

package com.cxsbg.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;

public class JwtUtil {
    //有效期
    public static final Long JWT_TTL=60*60*1000L;//一个小时
    //设置密钥明文
    public static final String JWT_KEY="cxs";

    /**
     * 创建token
     * @param id
     * @param subject
     * @param ttlMillis 最长有效期
     * @return
     */
    public static String createJWT(String id,String subject,Long ttlMillis){
        SignatureAlgorithm signatureAlgorithm=SignatureAlgorithm.HS256;

        long nowMills=System.currentTimeMillis();//当前时间
        Date now=new Date(nowMills);//当前时间
        if(ttlMillis==null){
            ttlMillis=JwtUtil.JWT_TTL;
        }
        long expMillis=nowMills+ttlMillis;//最长过期时间
        Date expDate=new Date(expMillis);//最长过期时间

        SecretKey secretKey=generalKey();//密钥

        JwtBuilder builder= Jwts.builder()
                .setId(id)//唯一的ID
                .setSubject(subject)//可以是json数据
                .setIssuer("sg")//签发者
                .setIssuedAt(now)//签发时间
                .signWith(signatureAlgorithm,secretKey)//使用对应的加密算法和密钥签名
                .setExpiration(expDate);//设置过期时间
        return builder.compact();
    }

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

        return key;
    }

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

    public static void main(String[] args) throws Exception {
        //获得token
        String token = JwtUtil.createJWT(UUID.randomUUID().toString(), "zhangsan", null);
        System.out.println(token);

        //解析token
        Claims claims = JwtUtil.parseJWT(token);
        String subject = claims.getSubject();
        System.out.println(subject);
    }
}

package com.cxsbg.controller;

import com.cxsbg.domain.ResponseResult;
import com.cxsbg.domain.SystemUser;
import com.cxsbg.service.SystemUserService;
import com.cxsbg.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.UUID;

@RestController
@RequestMapping("/sys_user")
public class SystemUserController {
    @Autowired
    private SystemUserService systemUserService;

    @PostMapping("/login")
    public ResponseResult login(@RequestBody SystemUser systemUser) {
        //校验用户名和密码是否正确
        SystemUser loginUser = systemUserService.login(systemUser);
        HashMap<String, Object> map;
        if (loginUser != null) {
            //登录成功，获取token
            String token = JwtUtil.createJWT(UUID.randomUUID().toString(), String.valueOf(loginUser.getId()), null);
            map = new HashMap<>();
            map.put("token", token);
        } else {
            return new ResponseResult(300, "登录失败");
        }
        return new ResponseResult(200, "登录成功", map);
    }
}

//存储token到本地
localStorage.setItem("token",res.data.data.token);