一个简单的jwt实例

package com.gl.gl_blog2.controller;

import com.gl.gl_blog2.entity.jwtBean;
import io.jsonwebtoken.*;
import org.springframework.web.bind.ServletRequestBindingException;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

import java.util.Date;
import java.util.UUID;

@RestController

public class JwtController {
    private long time = 10000; //毫秒为单位 1秒=1000毫秒
    private String signature = "admin";

    @CrossOrigin(origins = "*")
    @PostMapping("/generalToken")
    public String generalToken(@RequestBody jwtBean jwtBean){
        System.out.println(jwtBean);
        JwtBuilder jwtBuilder = Jwts.builder();
        String jwtToken = jwtBuilder
                .setHeaderParam("typ","JWT")
                .setHeaderParam("alg","HS256")
                .claim("username",jwtBean.getUsername())
                .claim("nickname",jwtBean.getNickname())
                .claim("quanxian","Teacher")
                .setSubject("admin-test")
                .setExpiration(new Date(System.currentTimeMillis()+time))
                .setId(UUID.randomUUID().toString())
                //signature
                .signWith(SignatureAlgorithm.HS256,signature)
                .compact();
        System.out.println(jwtToken);
        return jwtToken;
    }

    @CrossOrigin(origins = "*")
    @PostMapping("/jwtCheck")
    private String jwtCheck(@RequestBody String token){
        JwtParser jwtParser = Jwts.parser();
        Jws<Claims> claimsJws = jwtParser.setSigningKey(signature).parseClaimsJws(token);
        Claims clamins = claimsJws.getBody();
        System.out.println(clamins);
        System.out.println("用户名："+clamins.get("username"));
        System.out.println("昵称："+clamins.get("nickname"));
        System.out.println("权限："+clamins.get("quanxian"));
        System.out.println("token-ID："+clamins.getId());
        System.out.println(clamins.getSubject());
        System.out.println("生成时间："+clamins.getExpiration());
        return clamins.toString();
    }

}

相关依赖：

        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.9.1</version>
        </dependency>

        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.1</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-impl</artifactId>
            <version>2.3.0</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-core</artifactId>
            <version>2.3.0</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>

 当前只是使用postman测试jwt的生成、解码、获取其中信息
若前端要使用：
进入页面时触发mounted 发送jwt进行校验 校验通过就获得用户数据
jwt通过localstrange永久存储在浏览器。因为jwt中有时间戳会自动过期，所以不用担心
前端进行api连接时可以在headers头部信息中加入存储在浏览器的token，校验通过就允许操作

后端获得token后去redis中查询，如果有相同token，就返回确认信息。后端获得redis的确认信息后，对token进行解码，再以json格式返回前端。至此前端通过jwt校验，并获得该token的用户信息数据。