jwt的一些封装

package study;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;

public class RsaUtils {

    private static final int DEFAULT_KEY_SIZE = 2048;
    /**
     * 从文件中读取公钥
     *
     * @param filename 公钥保存路径，相对于classpath
     * @return 公钥对象
     * @throws Exception
     */
    public static PublicKey getPublicKey(String filename) throws Exception {
        byte[] bytes = readFile(filename);
        return getPublicKey(bytes);
    }

    /**
     * 从文件中读取密钥
     *
     * @param filename 私钥保存路径，相对于classpath
     * @return 私钥对象
     * @throws Exception
     */
    public static PrivateKey getPrivateKey(String filename) throws Exception {
        byte[] bytes = readFile(filename);
        return getPrivateKey(bytes);
    }

    /**
     * 获取公钥
     *
     * @param bytes 公钥的字节形式
     * @return
     * @throws Exception
     */
    private static PublicKey getPublicKey(byte[] bytes) throws Exception {
        bytes = Base64.getDecoder().decode(bytes);
        X509EncodedKeySpec spec = new X509EncodedKeySpec(bytes);
        KeyFactory factory = KeyFactory.getInstance("RSA");
        return factory.generatePublic(spec);
    }

    /**
     * 获取密钥
     *
     * @param bytes 私钥的字节形式
     * @return
     * @throws Exception
     */
    private static PrivateKey getPrivateKey(byte[] bytes) throws NoSuchAlgorithmException, InvalidKeySpecException {
        bytes = Base64.getDecoder().decode(bytes);
        PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(bytes);
        KeyFactory factory = KeyFactory.getInstance("RSA");
        return factory.generatePrivate(spec);
    }

    /**
     * 根据密文，生存rsa公钥和私钥,并写入指定文件
     *
     * @param publicKeyFilename  公钥文件路径
     * @param privateKeyFilename 私钥文件路径
     * @param secret             生成密钥的密文
     */
    public static void generateKey(String publicKeyFilename, String privateKeyFilename, String secret, int keySize) throws Exception {
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        SecureRandom secureRandom = new SecureRandom(secret.getBytes());
        keyPairGenerator.initialize(Math.max(keySize, DEFAULT_KEY_SIZE), secureRandom);
        KeyPair keyPair = keyPairGenerator.genKeyPair();
        // 获取公钥并写出
        byte[] publicKeyBytes = keyPair.getPublic().getEncoded();
        publicKeyBytes = Base64.getEncoder().encode(publicKeyBytes);
        writeFile(publicKeyFilename, publicKeyBytes);
        // 获取私钥并写出
        byte[] privateKeyBytes = keyPair.getPrivate().getEncoded();
        privateKeyBytes = Base64.getEncoder().encode(privateKeyBytes);
        writeFile(privateKeyFilename, privateKeyBytes);
    }

    private static byte[] readFile(String fileName) throws Exception {
        return Files.readAllBytes(new File(fileName).toPath());
    }

    private static void writeFile(String destPath, byte[] bytes) throws IOException {
        File dest = new File(destPath);
        if (!dest.exists()) {
            dest.createNewFile();
        }
        Files.write(dest.toPath(), bytes);
    }
}

package study;

import java.util.Date;
import java.util.HashMap;
import java.util.Map;

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

/**
 * @author Administrator 简单的字符串生成
 */
public abstract class JWTUtils {

    public static final String UID = "uid";
    private static final String SECRET = "aflkdsfkliewqfhksa";
    private static final long EXPIRE = 1 * 1000;

    private static final String pubKey = "D:\11.pub";
    private static final String priKey = "D:\11.se";

    /**
     * 生成token
     *
     * @param uid
     * @return
     */
    public static String generate(Integer uid) {
        Date nowDate = new Date();
        // 过期时间
        Date expireDate = new Date(nowDate.getTime() + EXPIRE * 1000);
        Map<String, Object> claims = new HashMap<>(1);
        claims.put(UID, uid);
        return Jwts.builder().setClaims(claims).setIssuedAt(nowDate).setExpiration(expireDate)
                .signWith(SignatureAlgorithm.HS512, SECRET).compact();
    }

    /**
     * 解析Claims
     *
     * @param token
     * @return
     */
    public static Claims getClaim(String token) {
        Claims claims = null;
        try {
            claims = Jwts.parser().setSigningKey(SECRET).parseClaimsJws(token).getBody();
        } catch (Exception e) {
            return null;
        }
        return claims;
    }

    /**
     * 获取jwt发布时间
     */
    public static Date getIssuedAt(String token) {
        return getClaim(token).getIssuedAt();
    }

    /**
     * 获取UID
     */
    public static Integer getUid(String token) {
        return Integer.valueOf(getClaim(token).get(UID).toString());
    }

    /**
     * 获取jwt失效时间
     */
    public static Date getExpiration(String token) {
        return getClaim(token).getExpiration();
    }

    /**
     * 验证token是否失效
     *
     * @param token
     * @return true:过期 false:没过期
     */
    public static boolean isExpired(String token) {
        try {
            final Date expiration = getExpiration(token);
            return expiration.before(new Date());
        } catch (ExpiredJwtException expiredJwtException) {
            return true;
        }
    }

}

package study;

import java.util.Date;
import java.util.HashMap;
import java.util.Map;

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

/**
 * @author Administrator rsa方式生成token
 */
public abstract class JWTRsaUtils {

    public static final String UID = "uid";
    private static final long EXPIRE = 1 * 1000;

    private static final String pubKey = "D:\11.pub";
    private static final String priKey = "D:\11.se";

    public static String generate(Integer uid) throws Exception {
        Date nowDate = new Date();
        // 过期时间
        Date expireDate = new Date(nowDate.getTime() + EXPIRE * 1000);
        Map<String, Object> claims = new HashMap<>(1);
        claims.put(UID, uid);
        return Jwts.builder().setClaims(claims).setIssuedAt(nowDate).setExpiration(expireDate)
                .signWith(SignatureAlgorithm.RS256, RsaUtils.getPrivateKey(priKey)).compact();
    }

    public static Claims getClaim(String token) {
        Claims claims = null;
        try {
            claims = Jwts.parser().setSigningKey(RsaUtils.getPublicKey(pubKey)).parseClaimsJws(token).getBody();
        } catch (Exception e) {
            return null;
        }
        return claims;
    }

    /**
     * 获取jwt发布时间
     */
    public static Date getIssuedAt(String token) {
        return getClaim(token).getIssuedAt();
    }

    /**
     * 获取UID
     */
    public static Integer getUid(String token) {
        return Integer.valueOf(getClaim(token).get(UID).toString());
    }

    /**
     * 获取jwt失效时间
     */
    public static Date getExpiration(String token) {
        return getClaim(token).getExpiration();
    }

    /**
     * 验证token是否失效
     *
     * @param token
     * @return true:过期 false:没过期
     */
    public static boolean isExpired(String token) {
        try {
            final Date expiration = getExpiration(token);
            return expiration.before(new Date());
        } catch (ExpiredJwtException expiredJwtException) {
            return true;
        }
    }

}

        // JWT测试
        // String token = JWTUtils.generate(123);
        // System.out.println(token);
        // Thread.sleep(2 * 1000);
        // System.out.println(JWTUtils.isExpired(token));
        // Integer uid = JWTUtils.getUid(token);
        // System.out.println(uid);

        // RsaUtils.generateKey("D:\11.pub", "D:\11.se", "122", 1024);

        String token = JWTRsaUtils.generate(123);
        System.out.println(token);
        System.out.println(JWTRsaUtils.getClaim(token));

        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.7.0</version>
        </dependency>
        <dependency>
            <groupId>com.auth0</groupId>
            <artifactId>java-jwt</artifactId>
            <version>3.4.0</version>
        </dependency>

token失效处理方式：

用户表维护一个登录时间字段lastLoginDate,每次登录,退出,修改密码都更新此字段,

然后jwt生成时有个签发时间,根据签发时间比对登录时间,

如果签发时间在登录时间前则视其为失效. 我的项目中用的jjwt(0.7.0版本),下面是代码示例

当然也可以用redis缓存，登录刷新即可