Java DigestOutputStream.flush方法代码示例

import java.security.DigestOutputStream; //导入方法依赖的package包/类
/**
 * Generate random contents for the image and store it together with the md5
 * for later comparison.
 */
private ContentBody genContent(long txid) throws IOException {
  MessageDigest digester = MD5Hash.getDigester();

  // write through digester so we can roll the written image
  ByteArrayOutputStream bos = new ByteArrayOutputStream(1024);
  DigestOutputStream ds = new DigestOutputStream(bos, digester);

  // generate random bytes
  new Random().nextBytes(randomBytes);
  ds.write(randomBytes);
  ds.flush();

  // get written hash
  MD5Hash hash = new MD5Hash(digester.digest());

  // store contents and digest
  digests.put(txid, hash);
  content.put(txid, Arrays.copyOf(randomBytes, randomBytes.length));

  return new ByteArrayBody(bos.toByteArray(), "filename");
}
 

import java.security.DigestOutputStream; //导入方法依赖的package包/类
public static byte [] writeRandomFile(int bytes, OutputStream out) throws IOException {
	try {
		DigestOutputStream dos = new DigestOutputStream(out, MessageDigest.getInstance(CCNDigestHelper.DEFAULT_DIGEST_ALGORITHM));

		byte [] buf = new byte[BUF_SIZE];
		int count = 0;
		int towrite = 0;
		while (count < bytes) {
			random.nextBytes(buf);
			towrite = ((bytes - count) > buf.length) ? buf.length : (bytes - count);
			dos.write(buf, 0, towrite);
			count += towrite;
		}
		dos.flush();
		dos.close();
		return dos.getMessageDigest().digest();

	} catch (NoSuchAlgorithmException e) {
		throw new RuntimeException("Cannot find digest algorithm: " + CCNDigestHelper.DEFAULT_DIGEST_ALGORITHM);
	}
}
 

import java.security.DigestOutputStream; //导入方法依赖的package包/类
/**
 * Encode and digest the object's content in order to detect changes made
 * outside of the object's own interface (for example, if the data is accessed
 * using data() and then modified).
 * @return
 * @throws ContentEncodingException if there is a problem encoding the content
 * @throws IOException if there is a problem writing the object to the stream.
 */
protected byte [] digestContent() throws ContentEncodingException, IOException {
	try {
		// Otherwise, might have been written when we weren't looking (someone accessed
		// data and then changed it).
		DigestOutputStream dos = new DigestOutputStream(new NullOutputStream(), MessageDigest.getInstance(DEFAULT_CHECKSUM_ALGORITHM));
		writeObjectImpl(dos);
		dos.flush();
		dos.close();
		byte [] currentValue = dos.getMessageDigest().digest();
		return currentValue;
	} catch (NoSuchAlgorithmException e) {
		Log.warning("No pre-configured algorithm {0} available -- configuration error!", DEFAULT_CHECKSUM_ALGORITHM);
		throw new RuntimeException("No pre-configured algorithm " + DEFAULT_CHECKSUM_ALGORITHM + " available -- configuration error!");
	}
}
 

import java.security.DigestOutputStream; //导入方法依赖的package包/类
private byte[] getHashValue(File file) throws Exception {
MessageDigest sha = MessageDigest.getInstance("SHA-256");

ByteArrayOutputStream baos = new ByteArrayOutputStream();
DigestOutputStream dout = new DigestOutputStream(baos, sha);

byte[] data = new byte[1024];

BufferedInputStream is = new BufferedInputStream(file.toURL().openStream());

while (true) {
    int bytesRead = is.read(data);
    if (bytesRead < 0)
	break;
    dout.write(data, 0, bytesRead);
}
dout.flush();
byte[] result = dout.getMessageDigest().digest();

return result;

   }
 

import java.security.DigestOutputStream; //导入方法依赖的package包/类
public boolean save(Avatar avatar) {
	File file;
	if (isAvatarCached(avatar)) {
		file = new File(getAvatarPath(avatar.getFilename()));
		avatar.size = file.length();
	} else {
		String filename = getAvatarPath(avatar.getFilename());
		file = new File(filename + ".tmp");
		file.getParentFile().mkdirs();
		OutputStream os = null;
		try {
			file.createNewFile();
			os = new FileOutputStream(file);
			MessageDigest digest = MessageDigest.getInstance("SHA-1");
			digest.reset();
			DigestOutputStream mDigestOutputStream = new DigestOutputStream(os, digest);
			final byte[] bytes = avatar.getImageAsBytes();
			mDigestOutputStream.write(bytes);
			mDigestOutputStream.flush();
			mDigestOutputStream.close();
			String sha1sum = CryptoHelper.bytesToHex(digest.digest());
			if (sha1sum.equals(avatar.sha1sum)) {
				file.renameTo(new File(filename));
			} else {
				Log.d(Config.LOGTAG, "sha1sum mismatch for " + avatar.owner);
				file.delete();
				return false;
			}
			avatar.size = bytes.length;
		} catch (IllegalArgumentException | IOException | NoSuchAlgorithmException e) {
			return false;
		} finally {
			close(os);
		}
	}
	return true;
}
 

import java.security.DigestOutputStream; //导入方法依赖的package包/类
public boolean save(Avatar avatar) {
	File file;
	if (isAvatarCached(avatar)) {
		file = new File(getAvatarPath(avatar.getFilename()));
	} else {
		String filename = getAvatarPath(avatar.getFilename());
		file = new File(filename + ".tmp");
		file.getParentFile().mkdirs();
		OutputStream os = null;
		try {
			file.createNewFile();
			os = new FileOutputStream(file);
			MessageDigest digest = MessageDigest.getInstance("SHA-1");
			digest.reset();
			DigestOutputStream mDigestOutputStream = new DigestOutputStream(os, digest);
			mDigestOutputStream.write(avatar.getImageAsBytes());
			mDigestOutputStream.flush();
			mDigestOutputStream.close();
			String sha1sum = CryptoHelper.bytesToHex(digest.digest());
			if (sha1sum.equals(avatar.sha1sum)) {
				file.renameTo(new File(filename));
			} else {
				Log.d(Config.LOGTAG, "sha1sum mismatch for " + avatar.owner);
				file.delete();
				return false;
			}
		} catch (IllegalArgumentException | IOException | NoSuchAlgorithmException e) {
			return false;
		} finally {
			close(os);
		}
	}
	avatar.size = file.length();
	return true;
}
 

import java.security.DigestOutputStream; //导入方法依赖的package包/类
private Avatar getPepAvatar(Bitmap bitmap, Bitmap.CompressFormat format, int quality) {
    try {
        ByteArrayOutputStream mByteArrayOutputStream = new ByteArrayOutputStream();
        Base64OutputStream mBase64OutputStream = new Base64OutputStream(mByteArrayOutputStream, Base64.DEFAULT);
        MessageDigest digest = MessageDigest.getInstance("SHA-1");
        DigestOutputStream mDigestOutputStream = new DigestOutputStream(mBase64OutputStream, digest);
        if (!bitmap.compress(format, quality, mDigestOutputStream)) {
            return null;
        }
        mDigestOutputStream.flush();
        mDigestOutputStream.close();
        long chars = mByteArrayOutputStream.size();
        if (format != Bitmap.CompressFormat.PNG && quality >= 50 && chars >= Config.AVATAR_CHAR_LIMIT) {
            int q = quality - 2;
            Log.d(Config.LOGTAG, "avatar char length was " + chars + " reducing quality to " + q);
            return getPepAvatar(bitmap, format, q);
        }
        Log.d(Config.LOGTAG, "settled on char length " + chars + " with quality=" + quality);
        final Avatar avatar = new Avatar();
        avatar.sha1sum = CryptoHelper.bytesToHex(digest.digest());
        avatar.image = new String(mByteArrayOutputStream.toByteArray());
        if (format.equals(Bitmap.CompressFormat.WEBP)) {
            avatar.type = "image/webp";
        } else if (format.equals(Bitmap.CompressFormat.JPEG)) {
            avatar.type = "image/jpeg";
        } else if (format.equals(Bitmap.CompressFormat.PNG)) {
            avatar.type = "image/png";
        }
        avatar.width = bitmap.getWidth();
        avatar.height = bitmap.getHeight();
        return avatar;
    } catch (Exception e) {
        return null;
    }
}
 

import java.security.DigestOutputStream; //导入方法依赖的package包/类
public boolean save(Avatar avatar) {
    File file;
    if (isAvatarCached(avatar)) {
        file = new File(getAvatarPath(avatar.getFilename()));
        avatar.size = file.length();
    } else {
        String filename = getAvatarPath(avatar.getFilename());
        file = new File(filename + ".tmp");
        file.getParentFile().mkdirs();
        OutputStream os = null;
        try {
            file.createNewFile();
            os = new FileOutputStream(file);
            MessageDigest digest = MessageDigest.getInstance("SHA-1");
            digest.reset();
            DigestOutputStream mDigestOutputStream = new DigestOutputStream(os, digest);
            final byte[] bytes = avatar.getImageAsBytes();
            mDigestOutputStream.write(bytes);
            mDigestOutputStream.flush();
            mDigestOutputStream.close();
            String sha1sum = CryptoHelper.bytesToHex(digest.digest());
            if (sha1sum.equals(avatar.sha1sum)) {
                file.renameTo(new File(filename));
            } else {
                Log.d(Config.LOGTAG, "sha1sum mismatch for " + avatar.owner);
                file.delete();
                return false;
            }
            avatar.size = bytes.length;
        } catch (IllegalArgumentException | IOException | NoSuchAlgorithmException e) {
            return false;
        } finally {
            close(os);
        }
    }
    return true;
}
 

import java.security.DigestOutputStream; //导入方法依赖的package包/类
private Avatar getPepAvatar(Bitmap bitmap, Bitmap.CompressFormat format, int quality) {
	try {
		ByteArrayOutputStream mByteArrayOutputStream = new ByteArrayOutputStream();
		Base64OutputStream mBase64OutputStream = new Base64OutputStream(mByteArrayOutputStream, Base64.DEFAULT);
		MessageDigest digest = MessageDigest.getInstance("SHA-1");
		DigestOutputStream mDigestOutputStream = new DigestOutputStream(mBase64OutputStream, digest);
		if (!bitmap.compress(format, quality, mDigestOutputStream)) {
			return null;
		}
		mDigestOutputStream.flush();
		mDigestOutputStream.close();
		long chars = mByteArrayOutputStream.size();
		if (format != Bitmap.CompressFormat.PNG && quality >= 50 && chars >= Config.AVATAR_CHAR_LIMIT) {
			int q = quality - 2;
			Log.d(Config.LOGTAG, "avatar char length was " + chars + " reducing quality to " + q);
			return getPepAvatar(bitmap, format, q);
		}
		Log.d(Config.LOGTAG, "settled on char length " + chars + " with quality=" + quality);
		final Avatar avatar = new Avatar();
		avatar.sha1sum = CryptoHelper.bytesToHex(digest.digest());
		avatar.image = new String(mByteArrayOutputStream.toByteArray());
		if (format.equals(Bitmap.CompressFormat.WEBP)) {
			avatar.type = "image/webp";
		} else if (format.equals(Bitmap.CompressFormat.JPEG)) {
			avatar.type = "image/jpeg";
		} else if (format.equals(Bitmap.CompressFormat.PNG)) {
			avatar.type = "image/png";
		}
		avatar.width = bitmap.getWidth();
		avatar.height = bitmap.getHeight();
		return avatar;
	} catch (Exception e) {
		return null;
	}
}
 

import java.security.DigestOutputStream; //导入方法依赖的package包/类
public static int writeFile(ContentName name, boolean random, int size, CCNHandle handle) throws Exception {
	int segmentsToWrite = 0;
	RepositoryFileOutputStream rfos = new RepositoryFileOutputStream(name.append("randomFile"), handle);
	DigestOutputStream dos = new DigestOutputStream(rfos, MessageDigest.getInstance(CCNDigestHelper.DEFAULT_DIGEST_ALGORITHM));

	byte [] buf = new byte[BUF_SIZE];
	int count = 0;
	int towrite = 0;
	Random rand = new Random();
	int bytes = 0;
	if (random) {
		bytes = rand.nextInt(maxBytes) + 1;
	} else
		bytes = size;
	double block = (double)bytes/(double)SystemConfiguration.BLOCK_SIZE;
	segmentsToWrite = (int) (Math.ceil(block) + 1);
	Log.fine(Log.FAC_TEST, "bytes: {0} block size: {1} div: {2} ceil: {3}", bytes, SystemConfiguration.BLOCK_SIZE, block, (int)Math.ceil(block));
	Log.fine(Log.FAC_TEST, "will write out a {0} byte file, will have {1} segments (1 is a header)", bytes, segmentsToWrite);
	while (count < bytes) {
		rand.nextBytes(buf);
		towrite = ((bytes - count) > buf.length) ? buf.length : (bytes - count);
		dos.write(buf, 0, towrite);
		count += towrite;
	}
	dos.flush();
	dos.close();
	Log.info(Log.FAC_TEST, "Wrote file to repository: {0} with {1} segments", rfos.getBaseName(), segmentsToWrite);
	return segmentsToWrite;
}
 

import java.security.DigestOutputStream; //导入方法依赖的package包/类
/**
 * @param completeName
 * @param fileLength
 * @param randBytes
 * @return
 * @throws IOException
 * @throws NoSuchAlgorithmException
 */
public static byte [] writeFile(Flosser flosser, ContentName completeName, int fileLength, Random randBytes) throws IOException, NoSuchAlgorithmException {
	flosser.handleNamespace(completeName);
	CCNOutputStream stockOutputStream = new CCNOutputStream(completeName, outputHandle);

	DigestOutputStream digestStreamWrapper = new DigestOutputStream(stockOutputStream, MessageDigest.getInstance("SHA1"));
	byte [] bytes = new byte[BUF_SIZE];
	int elapsed = 0;
	int nextBufSize = 0;

	Log.info(Log.FAC_TEST, "Writing file: " + completeName + " bytes: " + fileLength);

	final double probFlush = .3;

	while (elapsed < fileLength) {
		nextBufSize = ((fileLength - elapsed) > BUF_SIZE) ? BUF_SIZE : (fileLength - elapsed);
		randBytes.nextBytes(bytes);
		digestStreamWrapper.write(bytes, 0, nextBufSize);
		elapsed += nextBufSize;
		Log.info(completeName + " wrote " + elapsed + " out of " + fileLength + " bytes.");
		if (randBytes.nextDouble() < probFlush) {
			Log.info(Log.FAC_TEST, "Flushing buffers.");

			digestStreamWrapper.flush();
		}
	}
	digestStreamWrapper.close();

	Log.info(Log.FAC_TEST, "Finished writing file " + completeName);
	return digestStreamWrapper.getMessageDigest().digest();
}
 

import java.security.DigestOutputStream; //导入方法依赖的package包/类
/**
 * Save the object and update the internal tracking digest of its last-saved content.
 * @param output stream to write to.
 * @throws ContentEncodingException if there is an error encoding the object
 * @throws IOException if there is an error writing the object to the network
 */
protected synchronized void internalWriteObject(OutputStream output) throws ContentEncodingException, IOException {
	try {
		DigestOutputStream dos = new DigestOutputStream(output, MessageDigest.getInstance(DEFAULT_CHECKSUM_ALGORITHM));
		writeObjectImpl(dos);
		dos.flush(); // do not close dos, as it will close the output, allow caller to close
		_lastSaved = dos.getMessageDigest().digest();
		setDirty(false);
		
	} catch (NoSuchAlgorithmException e) {
		Log.warning("No pre-configured algorithm {0} available -- configuration error!", DEFAULT_CHECKSUM_ALGORITHM);
		throw new RuntimeException("No pre-configured algorithm " + DEFAULT_CHECKSUM_ALGORITHM + " available -- configuration error!");
	}
}