java加密大文件导致java.lang.OutOfMemoryError : Java heap space,可能的解决方案

Question

我正在编写java程序来加密视频文件，对于小视频文件，它会按预期执行，但是当我尝试处理大约800兆字节的大文件时，它会抛出异常java.lang.OutOfMemoryError:Java 堆空间。我研究了这个主题，从 here 获取有关垃圾收集器的更多信息。并审查类似问题here 。根据最佳选择的答案，如何“一次加密一个字节”:使用 block 密码加密是按 block (AES:16字节)进行的。我的源代码的内容

main.java

public static void main(String[] args) {
    String key = "Mary has one cat";
    File inputFile = new File("C:\\Users\\xyz\\Music\\test\\-.mp4");
    File encryptedFile = new File("C:\\Users\\xyz\\Music\\test\\-.mp4.encrypted");
    File decryptedFile = new File("C:\\Users\\xyz\\Music\\test\\decrypted.mp4");

    try {
        CryptoUtils.encrypt(key, inputFile, encryptedFile);
        CryptoUtils.decrypt(key, encryptedFile, decryptedFile);
    } catch (CryptoException ex) {
        System.out.println(ex.getMessage());
        ex.printStackTrace();
    }
}

CryptoUtils.java

 private static final String ALGORITHM = "AES";
private static final String TRANSFORMATION = "AES";

public static void encrypt(String key, File inputFile, File outputFile)
        throws CryptoException {
    doCrypto(Cipher.ENCRYPT_MODE, key, inputFile, outputFile);
}

public static void decrypt(String key, File inputFile, File outputFile)
        throws CryptoException {
    doCrypto(Cipher.DECRYPT_MODE, key, inputFile, outputFile);
}

private static void doCrypto(int cipherMode, String key, File inputFile,
        File outputFile) throws CryptoException {
    try {
        Key secretKey = new SecretKeySpec(key.getBytes(), ALGORITHM);
        Cipher cipher = Cipher.getInstance(TRANSFORMATION);
        cipher.init(cipherMode, secretKey);

        FileInputStream inputStream = new FileInputStream(inputFile);
        byte[] inputBytes = new byte[(int) inputFile.length()];
        inputStream.read(inputBytes);

        byte[] outputBytes = cipher.doFinal(inputBytes);

        FileOutputStream outputStream = new FileOutputStream(outputFile);
        outputStream.write(outputBytes);

        inputStream.close();
        outputStream.close();

    } catch (NoSuchPaddingException | NoSuchAlgorithmException
            | InvalidKeyException | BadPaddingException
            | IllegalBlockSizeException | IOException ex) {
        throw new CryptoException("Error encrypting/decrypting file", ex);
    }
}

CryptoException.java

public class CryptoException extends Exception {

public CryptoException() {
}

public CryptoException(String message, Throwable throwable) {
    super(message, throwable);
}}

Answer 1

我认为您应该考虑使用 CipherOutputStream。这样您就不需要将文件加载到内存中:

https://docs.oracle.com/javase/9/docs/api/javax/crypto/CipherOutputStream.html