package com.ucf.gatewaycheck.utils;

import java.util.zip.GZIPInputStream; 
import java.io.FileOutputStream; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.IOException; 

import org.apache.log4j.Logger;

public class GZIPFileUtil { 
	private static final Logger log=Logger.getLogger(GZIPFileUtil.class);
	/** 
	 * Uncompress the incoming file. 
	 * @param inFileName Name of the file to be uncompressed 
	 */ 
	public  static String doUncompressFile(String inFileName) { 
		log.info("建行快捷对账文件解压文件名：["+inFileName+"]");
		GZIPInputStream in = null; 
		FileOutputStream out = null; 
		try { 
			if (!getExtension(inFileName).equalsIgnoreCase("gz")) { 
				log.error("File name must have extension of \".gz\""); 
				System.exit(1); 
			} 
			try { 
				in = new GZIPInputStream(new FileInputStream(inFileName)); 
			} catch(FileNotFoundException e) { 
				log.error("File not found. " + inFileName); 
				System.exit(1); 
			} 
			String outFileName = getFileName(inFileName); 
			try { 
				out = new FileOutputStream(outFileName); 
			} catch (FileNotFoundException e) { 
				log.error("Could not write to file. " + outFileName); 
				System.exit(1); 
			} 
			byte[] buf = new byte[1024]; 
			int len; 
			while((len = in.read(buf)) > 0) { 
				out.write(buf, 0, len); 
			} 
			log.info("建行快捷对账文件解压保存路径：["+outFileName+"]");
			return outFileName;
		} catch (IOException e) { 
			log.error("File write Fail!");
			System.exit(1); 
		}finally{
			try {
				if (in != null) {
					in.close();
				}
				if (out != null) {
					out.close();
				}
			} catch (IOException e) {
				log.error(e);
			}
		}
		return null;
	} 

	/** 
	 * Used to extract and return the extension of a given file. 
	 * @param f Incoming file to get the extension of 
	 * @return <code>String</code> representing the extension of the incoming 
	 *  file. 
	 */ 
	public static String getExtension(String f) { 
		String ext = ""; 
		int i = f.lastIndexOf('.'); 
		if (i > 0 &&  i < f.length() - 1) { 
			ext = f.substring(i+1); 
		}      
		return ext; 
	} 

	/** 
	 * Used to extract the filename without its extension. 
	 * @param f Incoming file to get the filename 
	 * @return <code>String</code> representing the filename without its 
	 *         extension. 
	 */ 
	public static String getFileName(String f) { 
		String fname = ""; 
		int i = f.lastIndexOf('.'); 
		if (i > 0 &&  i < f.length() - 1) { 
			fname = f.substring(0,i); 
		}      
		return fname; 
	} 

	/** 
	 * Sole entry point to the class and application. 
	 * @param args Array of String arguments. 
	 */ 
	public static void main(String[] args) { 
	String mess=doUncompressFile("E:/CCBKJ/SHOP.105290073991463.20150329.KJZF.txt.gz"); 
      System.out.println(mess);
	} 

} 

文件压缩：

package com.ucf.gatewaycheck.service.impl;

import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.util.zip.GZIPOutputStream; 


public class CompressFileGZIP { 
	private static void doCompressFile(String inFileName) { 
		try { 
			System.out.println("Creating the GZIP output stream."); 
			String outFileName = inFileName + ".gz"; 
			GZIPOutputStream out = null; 
			try { 
				out = new GZIPOutputStream(new FileOutputStream(outFileName)); 
			} catch(FileNotFoundException e) { 
				System.err.println("Could not create file: " + outFileName); 
				System.exit(1); 
			} 
			System.out.println("Opening the input file."); 
			FileInputStream in = null; 
			try { 
				in = new FileInputStream(inFileName); 
			} catch (FileNotFoundException e) { 
				System.err.println("File not found. " + inFileName); 
				System.exit(1); 
			} 

			System.out.println("Transfering bytes from input file to GZIP Format."); 
			byte[] buf = new byte[1024]; 
			int len; 
			while((len = in.read(buf)) > 0) { 
				out.write(buf, 0, len); 
			} 
			in.close(); 

			System.out.println("Completing the GZIP file"); 
			out.finish(); 
			out.close(); 

		} catch (IOException e) { 
			e.printStackTrace(); 
			System.exit(1); 
		} 

	} 

	/** 
	 * Sole entry point to the class and application. 
	 * @param args Array of String arguments. 
	 */ 
	public static void main(String[] args) { 
		String str="E:\\AUTORUN.INF"; 

		doCompressFile(str); 



	} 
}