package test;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.zip.GZIPInputStream;
/**
 * 解壓.gz檔案
 * @author www
 *
 */
public class Gzip {
	
	public static final int BUFFER = 1024;
	public static final String EXT = ".gz";


	public static void main(String[] args) {
		try {
			deCompress("檔案路徑");
		} catch (Exception e) {
			throw new RuntimeException("解壓檔案失敗！", e);
		}
	}
	
	/**
	 * 檔案解壓縮
	 * @param file
	 * @throws Exception 
	 */
	public static void deCompress(String fileName) throws Exception {
		File file = new File(fileName);
		System.out.println(file);
		decompressFile(file, false);
	}
	
	/**
	 * 檔案解壓縮，是否刪除原檔案
	 * @param file
	 * @param delete
	 * @throws Exception
	 */
	public static void decompressFile (File file,boolean delete) throws Exception{
		FileOutputStream fos = new FileOutputStream(file);
		FileInputStream fis = new FileInputStream(file.getPath().replace(EXT, ""));
		decompress(fis, fos);
		fis.close();
		fos.flush();
		fos.close();
		if(delete) {
			file.delete();
		}
	}
	
	/**
	 * 資料解壓縮
	 * @param is
	 * @param os
	 * @throws Exception
	 */
	public static void decompress(InputStream is, OutputStream os) throws Exception {
		GZIPInputStream gis = new GZIPInputStream(is);
		int count;
		byte[] data = new byte[1024];
		while((count = gis.read(data,0,BUFFER))!=-1) {
			os.write(data,0,count);
		}
	}
	
	
}