FileOutputStream和PrintWriter之间的区别

Question

我正在我的应用程序中实现SSL证书和密钥.我使用CertAndKeyGen类创建了私钥.我试图用密码加密私钥,我通过PBE和Cipher类实现了它.我想将加密的私钥写入PEM格式的文​​件中.我尝试使用FileOutputStream,但PrintWriter不能正常工作.

以下是我的代码,

    final CertAndKeyGen keypair = new CertAndKeyGen("RSA", "SHA1WithRSA", null);
    keypair.generate(1024);
    final PrivateKey privKey = keypair.getPrivateKey();
    byte[] encodedprivkey = privKey.getEncoded();
    String MYPBEALG = "PBEWithSHA1AndDESede";
    String password = "test123";
    int count = 20;// hash iteration count
    Random random = new Random();
    byte[] salt = new byte[8];
    random.nextBytes(salt);
    PBEParameterSpec pbeParamSpec = new PBEParameterSpec(salt, count);
    PBEKeySpec pbeKeySpec = new PBEKeySpec(password.toCharArray());
    SecretKeyFactory keyFac = SecretKeyFactory.getInstance(MYPBEALG);
    SecretKey pbeKey = keyFac.generateSecret(pbeKeySpec);
    Cipher pbeCipher = Cipher.getInstance(MYPBEALG);
    // Initialize PBE Cipher with key and parameters
    pbeCipher.init(Cipher.ENCRYPT_MODE, pbeKey, pbeParamSpec);
    // Encrypt the encoded Private Key with the PBE key
    byte[] ciphertext = pbeCipher.doFinal(encodedprivkey);
    // Now construct  PKCS #8 EncryptedPrivateKeyInfo object
    AlgorithmParameters algparms = AlgorithmParameters.getInstance(MYPBEALG);
    algparms.init(pbeParamSpec);
    EncryptedPrivateKeyInfo encinfo = new EncryptedPrivateKeyInfo(algparms,ciphertext);
    byte[] encryptedPkcs8 = encinfo.getEncoded();

    // Now I am writing the encrypted private key into a file.
    // Using FileOutputStream 

    FileOutputStream out = new FileOutputStream("usingOutEncrypedPrivkey");
    out.write(Base64.encodeBase64(encryptedPkcs8, true));
    out.flush();
    out.close();

    // Using PrintWriter 
    PrintWriter pw = new PrintWriter("usingPwEncryptedPrivKey");
    pw.println("-----BEGIN "+ privKey.getAlgorithm() + " PRIVATE KEY-----");
    pw.println(Base64.encodeBase64(encryptedPkcs8));
    pw.println("-----END "+ privKey.getAlgorithm() +" PRIVATE KEY-----");
    pw.close();

以下是保存的文件,

    usingOutEncrypedPrivkey  // Which was saved using FileOutputStream

    MIICoTAbBgoqhkiG9w0BDAEDMA0ECL4xgraq2hXxAgEUBIICgFENaB8EA/kR0ymSC8vcyj1fNFbP
    iR+mXkBk7aH3eF7fpP8yqCvtN0/0VqHi/w/Z2CLgiib2s/zuiVPtWI8vsRRPXmD9PYxZp3ilLpD4
                            .....
                            .....   
    9nH8HdQf584c3sKYEErDQvJR2SmbUPtNq4cB6ocUuiOTztBqRXAHeaWavnqHFxHUT7c=


    usingPwEncryptedPrivKey  // Which was saved using PrintWriter
   -----BEGIN RSA PRIVATE KEY-----
   [B@19e3118a
   -----END RSA PRIVATE KEY-----

为什么PrintWriter写为"[B @ 19e3118a",而不是像FileOutputStream这样的字节.我想使用PrintWriter,因为我想使用PrintWriter.println()函数.请帮帮我.提前致谢.

Answer 1

• OutputStream.write(byte[]) 将字节写为二进制数据.
• PrintWriter.print(byte[])调用toString()数组并写出结果.这[B@19e3118a是toString()你的数组的表示.

鉴于字符串只包含ASCII字符,您可以String(byte[])在数组上使用,并打印结果.

或者,如果您使用的是Apache Commons Base64类,则应该使用该encodeBase64String()方法而不是encodeBase64()[Thanks @SimonC].