CodecUtils.java

/**
 * Copyright 2011-2012 Alexandre Dutra
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License 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 fr.dutra.confluence2wordpress.util;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

import org.apache.commons.codec.binary.Base64InputStream;
import org.apache.commons.codec.binary.Base64OutputStream;
import org.apache.commons.codec.digest.DigestUtils;
import org.apache.commons.io.IOUtils;
import org.apache.commons.io.output.ByteArrayOutputStream;

public class CodecUtils {

	private static final String UTF_8 = "UTF-8";

	public static String compressAndEncode(String text) throws IOException {
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		GZIPOutputStream gzos = new GZIPOutputStream(new Base64OutputStream(baos));
		try {
			gzos.write(text.getBytes(UTF_8));
		} finally {
			baos.close();
			gzos.close();
		}
		return new String(baos.toByteArray(), UTF_8);
	}

	public static String decodeAndExpand(String encoded) throws IOException {
		GZIPInputStream gzis = 
			new GZIPInputStream(
				new Base64InputStream(
					new ByteArrayInputStream(
						encoded.getBytes(UTF_8))));
		try {
			return IOUtils.toString(gzis, UTF_8);
		} finally {
			gzis.close();
		}
	}

	/**
	 * Returns the MD5 hash of the given email, as required by Gravatar.
	 * @see "http://fr.gravatar.com/site/implement/hash/"
	 * @param email
	 * @return
	 */
	public static String gravatarHash(String email) {
		return DigestUtils.md5Hex(email.trim().toLowerCase());
	}
}