com.amazonaws.util.BinaryUtils Maven / Gradle / Ivy
/*
* Copyright 2010-2013 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Portions copyright 2006-2009 James Murty. Please see LICENSE.txt
* for applicable license terms and NOTICE.txt for applicable notices.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file is distributed
* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
package com.amazonaws.util;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.util.Locale;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Utilities for encoding and decoding binary data to and from different forms.
*/
public class BinaryUtils {
/** Default encoding when extracting binary data from a String */
private static final String DEFAULT_ENCODING = "UTF-8";
private static final Log log = LogFactory.getLog(BinaryUtils.class);
/**
* Converts byte data to a Hex-encoded string.
*
* @param data
* data to hex encode.
*
* @return hex-encoded string.
*/
public static String toHex(byte[] data) {
StringBuilder sb = new StringBuilder(data.length * 2);
for (int i = 0; i < data.length; i++) {
String hex = Integer.toHexString(data[i]);
if (hex.length() == 1) {
// Append leading zero.
sb.append("0");
} else if (hex.length() == 8) {
// Remove ff prefix from negative numbers.
hex = hex.substring(6);
}
sb.append(hex);
}
return sb.toString().toLowerCase(Locale.getDefault());
}
/**
* Converts a Hex-encoded data string to the original byte data.
*
* @param hexData
* hex-encoded data to decode.
* @return decoded data from the hex string.
*/
public static byte[] fromHex(String hexData) {
byte[] result = new byte[(hexData.length() + 1) / 2];
String hexNumber = null;
int stringOffset = 0;
int byteOffset = 0;
while (stringOffset < hexData.length()) {
hexNumber = hexData.substring(stringOffset, stringOffset + 2);
stringOffset += 2;
result[byteOffset++] = (byte) Integer.parseInt(hexNumber, 16);
}
return result;
}
/**
* Converts byte data to a Base64-encoded string.
*
* @param data
* data to Base64 encode.
* @return encoded Base64 string.
*/
public static String toBase64(byte[] data) {
byte[] b64 = Base64.encodeBase64(data);
return new String(b64);
}
/**
* Converts a Base64-encoded string to the original byte data.
*
* @param b64Data
* a Base64-encoded string to decode.
*
* @return bytes decoded from a Base64 string.
*/
public static byte[] fromBase64(String b64Data) {
byte[] decoded;
try {
decoded = Base64.decodeBase64(b64Data.getBytes(DEFAULT_ENCODING));
} catch (UnsupportedEncodingException uee) {
// Shouldn't happen if the string is truly Base64 encoded.
log.warn("Tried to Base64-decode a String with the wrong encoding: ", uee);
decoded = Base64.decodeBase64(b64Data.getBytes());
}
return decoded;
}
/**
* Wraps a ByteBuffer in an InputStream.
*
* @param byteBuffer The ByteBuffer to wrap.
*
* @return An InputStream wrapping the ByteBuffer content.
*/
public static InputStream toStream(ByteBuffer byteBuffer) {
byte[] bytes = new byte[byteBuffer.remaining()];
byteBuffer.get(bytes);
return new ByteArrayInputStream(bytes);
}
}