生成jwt时使用签名算法生成签名部分

1 、基于HS256签名算法

@Test
    public void test2(){
        //添加构成JWT的参数
        Map<String, Object> headMap = new HashMap();
        headMap.put("alg", SignatureAlgorithm.HS256.getValue());//使用HS256签名算法
        headMap.put("typ", "JWT");

        Map body = new HashMap();
        body.put("userId","1");
        body.put("username","xiaoming");
        body.put("role","admin");

        String jwt = Jwts.builder()
                        .setHeader(headMap)
                        .setClaims(body)
                        .setId("jwt001")
            			.signWith(SignatureAlgorithm.HS256,"javahorse")
            			.compact();
        System.out.println(jwt);

        //解析jwt
        Jwt result = Jwts.parser().setSigningKey("javahorse").parse(jwt);
        Object jwtBody = result.getBody();
        Header header = result.getHeader();

        System.out.println(result);
        System.out.println(jwtBody);
        System.out.println(header);
    }

2 、基于RS256签名算法

@Test
    public void test3() throws Exception{
        //添加构成JWT的参数
        Map<String, Object> headMap = new HashMap();
        headMap.put("alg", SignatureAlgorithm.RS256.getValue());//使用RS256签名算法
        headMap.put("typ", "JWT");

        Map body = new HashMap();
        body.put("userId","1");
        body.put("username","xiaoming");
        body.put("role","admin");

        String jwt = Jwts.builder()
                .setHeader(headMap)
                .setClaims(body)
                .setId("jwt001")
                .signWith(SignatureAlgorithm.RS256,getPriKey())
                .compact();
        System.out.println(jwt);

        //解析jwt
        Jwt result = Jwts.parser().setSigningKey(getPubKey()).parse(jwt);
        Object jwtBody = result.getBody();
        Header header = result.getHeader();

        System.out.println(result);
        System.out.println(jwtBody);
        System.out.println(header);
    }

    //获取私钥
    public PrivateKey getPriKey() throws Exception{
        InputStream resourceAsStream = 
            this.getClass().getClassLoader().getResourceAsStream("pri.key");
        DataInputStream dis = new DataInputStream(resourceAsStream);
        byte[] keyBytes = new byte[resourceAsStream.available()];
        dis.readFully(keyBytes);
        PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory kf = KeyFactory.getInstance("RSA");
        return kf.generatePrivate(spec);
    }

    //获取公钥
    public PublicKey getPubKey() throws Exception{
        InputStream resourceAsStream = 
            this.getClass().getClassLoader().getResourceAsStream("pub.key");
        DataInputStream dis = new DataInputStream(resourceAsStream);
        byte[] keyBytes = new byte[resourceAsStream.available()];
        dis.readFully(keyBytes);
        X509EncodedKeySpec spec = new X509EncodedKeySpec(keyBytes);
        KeyFactory kf = KeyFactory.getInstance("RSA");
        return kf.generatePublic(spec);
    }

3 、生成自己的 秘钥/公钥 对

@Test
    public void test4() throws Exception{
        //自定义 随机密码,  请修改这里
        String password = "javahorse";

        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        SecureRandom secureRandom = new SecureRandom(password.getBytes());
        keyPairGenerator.initialize(1024, secureRandom);
        KeyPair keyPair = keyPairGenerator.genKeyPair();

        byte[] publicKeyBytes = keyPair.getPublic().getEncoded();
        byte[] privateKeyBytes = keyPair.getPrivate().getEncoded();

        FileUtil.writeBytes(publicKeyBytes, "d:\\pub.key");
        FileUtil.writeBytes(privateKeyBytes, "d:\\pri.key");
    }