压缩成.gz格式

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);   }
}   

解压.gz格式

import java.util.zip.GZIPInputStream;
import java.io.FileOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;   public class UncompressFileGZIP {   /**  * Uncompress the incoming file.  * @param inFileName Name of the file to be uncompressed  */   private static void doUncompressFile(String inFileName) {   try {   if (!getExtension(inFileName).equalsIgnoreCase("gz")) {   System.err.println("File name must have extension of \".gz\"");   System.exit(1);   }   System.out.println("Opening the compressed file.");   GZIPInputStream in = null;   try {   in = new GZIPInputStream(new FileInputStream(inFileName));   } catch(FileNotFoundException e) {   System.err.println("File not found. " + inFileName);   System.exit(1);   }   System.out.println("Open the output file.");   String outFileName = getFileName(inFileName);   FileOutputStream out = null;   try {   out = new FileOutputStream(outFileName);   } catch (FileNotFoundException e) {   System.err.println("Could not write to file. " + outFileName);   System.exit(1);   }   System.out.println("Transfering bytes from compressed file to the output file.");   byte[] buf = new byte[1024];   int len;   while((len = in.read(buf)) > 0) {   out.write(buf, 0, len);   }   System.out.println("Closing the file and stream");   in.close();   out.close();   } catch (IOException e) {   e.printStackTrace();   System.exit(1);   }   }   /**  * 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) {   doUncompressFile("E:\\AUTORUN.INF.gz");   }   }   

本文出处：http://panshaobinsb.iteye.com/blog/1566231