jwt 的一个例子

解析和 生成 token
[quote]
https://blog.csdn.net/qq_40081976/article/details/79046825
[/quote]

package com.zyd.jwt;

import java.util.Date;

import javax.crypto.spec.SecretKeySpec;
import javax.xml.bind.DatatypeConverter;
import java.security.Key;

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

public class JwtHelper {

	    private final static String base64Secret = "MDk4ZjZiY2Q0NjIxZDM3M2NhZGU0ZTgzMjYyN2I0ZjY=";
	    private final static int expiresSecond = 172800000;

	    public static Claims parseJWT(String jsonWebToken) {
	        try {
	            Claims claims = Jwts.parser()
	                    .setSigningKey(DatatypeConverter.parseBase64Binary(base64Secret))
	                    .parseClaimsJws(jsonWebToken).getBody();
	            return claims;
	        } catch (Exception ex) {
	            return null;
	        }
	    }

	    public static String createJWT(String username, String roles, String privileges) {
	        SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.HS256;

	        long nowMillis = System.currentTimeMillis();
	        Date now = new Date(nowMillis);

	        //生成签名**
	        byte[] apiKeySecretBytes = DatatypeConverter.parseBase64Binary(base64Secret);
	        Key signingKey = new SecretKeySpec(apiKeySecretBytes, signatureAlgorithm.getJcaName());

	        //添加构成JWT的参数
	        JwtBuilder builder = Jwts.builder().setHeaderParam("typ", "JWT")
	                .claim("user_name", username)
	                .claim("user_role", roles)
	                .claim("user_privilege", privileges)
	                .signWith(signatureAlgorithm, signingKey);
	        //添加Token过期时间
	        if (expiresSecond >= 0) {
	            long expMillis = nowMillis + expiresSecond;
	            Date exp = new Date(expMillis);
	            builder.setExpiration(exp).setNotBefore(now);
	        }

	        //生成JWT
	        return builder.compact();
	    }
}

<dependency>
		<groupId>io.jsonwebtoken</groupId>
	    <artifactId>jjwt</artifactId>
	    <version>0.7.0</version>
    </dependency>