GZIP压缩解压缩

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
import org.apache.commons.codec.binary.StringUtils;
/**
 * 
 * @author Lian Shan Yang
 * GZIP 工具类
 */
public class GZIPUtils {
	public static final String GZIP_ENCODE_UTF_8 = "UTF-8";

	public static final String GZIP_ENCODE_ISO_8859_1 = "ISO-8859-1";

	/**
	 * 字符串压缩为GZIP字节数组
	 * 
	 * @param str
	 * @return
	 */
	public static byte[] compress(String str) {
		return compress(str, GZIP_ENCODE_UTF_8);
	}

	/**
	 * 字符串压缩为GZIP字节数组
	 * 
	 * @param str
	 * @param encoding
	 * @return
	 */
	public static byte[] compress(String str, String encoding) {
		if (str == null || str.length() == 0) {
			return null;
		}
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		GZIPOutputStream gzip;
		try {
			gzip = new GZIPOutputStream(out);
			gzip.write(str.getBytes(encoding));
			gzip.close();
		} catch (IOException e) {
		}
		return out.toByteArray();
	}

	/**
	 * GZIP解压缩
	 * 
	 * @param bytes
	 * @return
	 */
	public static byte[] uncompress(byte[] bytes) {
		if (bytes == null || bytes.length == 0) {
			return null;
		}
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		ByteArrayInputStream in = new ByteArrayInputStream(bytes);
		try {
			GZIPInputStream ungzip = new GZIPInputStream(in);
			byte[] buffer = new byte[256];
			int n;
			while ((n = ungzip.read(buffer)) >= 0) {
				out.write(buffer, 0, n);
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
		return out.toByteArray();
	}

	/**
	 * 
	 * @param bytes
	 * @return
	 */
	public static String uncompressToString(byte[] bytes) {
		return uncompressToString(bytes, GZIP_ENCODE_UTF_8);
	}

	/**
	 * 
	 * @param bytes
	 * @param encoding
	 * @return
	 */
	public static String uncompressToString(byte[] bytes, String encoding) {
		if (bytes == null || bytes.length == 0) {
			return null;
		}
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		ByteArrayInputStream in = new ByteArrayInputStream(bytes);
		try {
			GZIPInputStream ungzip = new GZIPInputStream(in);
			byte[] buffer = new byte[256];
			int n;
			while ((n = ungzip.read(buffer)) >= 0) {
				out.write(buffer, 0, n);
			}
			return out.toString(encoding);
		} catch (IOException e) {
			e.printStackTrace();
		}
		return null;
	}

	public static void main(String[] args) {
		String str = "yanglianshagnsdfaskdfsdfasdfasdfkas;d dsfasdkfjasld;kfas sdfjaskdl;fjask dfa ";
		System.out.println("原长度：" + str.length());
		System.out.println("压缩后字符串：" + GZIPUtils.compress(str).toString().length());
		System.out.println("解压缩后字符串：" + StringUtils.newStringUtf8(GZIPUtils.uncompress(GZIPUtils.compress(str))));
		System.out.println("解压缩后字符串：" + GZIPUtils.uncompressToString(GZIPUtils.compress(str)));
	}
}