Java 使用 GZIP 進行壓縮和解壓縮

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

/**


Used to provide an example of compressing a file using the GZIP Format.
*
@version 1.0
@author  Jeffrey M. Hunter  (jhunter@idevelopment.info)
@author  <a href="http://www.idevelopment.info">http://www.idevelopment.info


*/
public class CompressFileGZIP {

/**
 * Perform file compression.
 * @param inFileName Name of the file to be compressed
 */
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) {

    if (args.length != 1) {
        System.err.println("Usage: java CompressFileGZIP filename");
    } else {
        doCompressFile(args[0]);
    }


}


}
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