java gzip壓縮解壓縮代碼

java Gzip壓縮實現代碼

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); 

} 

} </pre>
 java Gzip解壓縮代碼 

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"); 

} 


}</pre>