Java实现数据压缩---ZLib压缩工具

package cn.wiki.openapi.lry.tool;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.zip.Deflater;
import java.util.zip.DeflaterOutputStream;
import java.util.zip.Inflater;
import java.util.zip.InflaterInputStream;

/**
 * Java实现数据压缩
 * ZLib压缩工具
 * @author lry
 *
 */
public abstract class ZLibUtils {

	/**
	 * 压缩
	 * 
	 * @param data
	 *            待压缩数据
	 * @return byte[] 压缩后的数据
	 */
	public static byte[] compress(byte[] data) {
		byte[] output = new byte[0];

		Deflater compresser = new Deflater();

		compresser.reset();
		compresser.setInput(data);
		compresser.finish();
		ByteArrayOutputStream bos = new ByteArrayOutputStream(data.length);
		try {
			byte[] buf = new byte[1024];
			while (!compresser.finished()) {
				int i = compresser.deflate(buf);
				bos.write(buf, 0, i);
			}
			output = bos.toByteArray();
		} catch (Exception e) {
			output = data;
			e.printStackTrace();
		} finally {
			try {
				bos.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		compresser.end();
		return output;
	}

	/**
	 * 压缩
	 * 
	 * @param data
	 *            待压缩数据
	 * 
	 * @param os
	 *            输出流
	 */
	public static void compress(byte[] data, OutputStream os) {
		DeflaterOutputStream dos = new DeflaterOutputStream(os);

		try {
			dos.write(data, 0, data.length);

			dos.finish();

			dos.flush();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	/**
	 * 解压缩
	 * 
	 * @param data
	 *            待压缩的数据
	 * @return byte[] 解压缩后的数据
	 */
	public static byte[] decompress(byte[] data) {
		byte[] output = new byte[0];

		Inflater decompresser = new Inflater();
		decompresser.reset();
		decompresser.setInput(data);

		ByteArrayOutputStream o = new ByteArrayOutputStream(data.length);
		try {
			byte[] buf = new byte[1024];
			while (!decompresser.finished()) {
				int i = decompresser.inflate(buf);
				o.write(buf, 0, i);
			}
			output = o.toByteArray();
		} catch (Exception e) {
			output = data;
			e.printStackTrace();
		} finally {
			try {
				o.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}

		decompresser.end();
		return output;
	}

	/**
	 * 解压缩
	 * 
	 * @param is
	 *            输入流
	 * @return byte[] 解压缩后的数据
	 */
	public static byte[] decompress(InputStream is) {
		InflaterInputStream iis = new InflaterInputStream(is);
		ByteArrayOutputStream o = new ByteArrayOutputStream(1024);
		try {
			int i = 1024;
			byte[] buf = new byte[i];

			while ((i = iis.read(buf, 0, i)) > 0) {
				o.write(buf, 0, i);
			}

		} catch (IOException e) {
			e.printStackTrace();
		}
		return o.toByteArray();
	}
	public static void main(String[] args) {
		 System.out.println("字节压缩／解压缩测试");  
	     String inputStr = "站搜啊的说得很好[email protected];[email protected];[email protected]";  
	     System.out.println("输入字符串:" + inputStr);  
	     byte[] input = inputStr.getBytes();  
	     System.out.println("输入字节长度:" + input.length);  
	  
	     byte[] data = ZLibUtils.compress(input);  
	     System.out.println("压缩后字节长度:" + data.length);  
	  
	     byte[] output = ZLibUtils.decompress(data);  
	     System.out.println("解压缩后字节长度:" + output.length);  
	     String outputStr = new String(output);  
	     System.out.println("输出字符串:" + outputStr);  
	}
}