JAVA实现压缩文件的方法（使用java.util.zip.*)

     以下是两个摘自《java examples in a nutshell》的两个方法，挺简单的。

 

 

    /** Gzip the contents of the from file and save in the to file. */
    public static void gzipFile(String from, String to) throws IOException {
        // Create stream to read from the from file
        FileInputStream in = new FileInputStream(from);
        // Create stream to compress data and write it to the to file.
        GZIPOutputStream out = new GZIPOutputStream(new FileOutputStream(to));
        // Copy bytes from one stream to the other
        byte[  ] buffer = new byte[4096];
        int bytes_read;
        while((bytes_read = in.read(buffer)) != -1)
            out.write(buffer, 0, bytes_read);
        // And close the streams
        in.close( );
        out.close( );
    }

    /** Zip the contents of the directory, and save it in the zipfile */
    public static void zipDirectory(String dir, String zipfile)
        throws IOException, IllegalArgumentException {
        // Check that the directory is a directory, and get its contents
        File d = new File(dir);
        if (!d.isDirectory( ))
            throw new IllegalArgumentException("Compress: not a directory:  " +
                                               dir);
        String[  ] entries = d.list( );
        byte[  ] buffer = new byte[4096];  // Create a buffer for copying
        int bytes_read;

        // Create a stream to compress data and write it to the zipfile
        ZipOutputStream out =
            new ZipOutputStream(new FileOutputStream(zipfile));

        // Loop through all entries in the directory
        for(int i = 0; i < entries.length; i++) {
            File f = new File(d, entries[i]);
            if (f.isDirectory( )) continue;        // Don't zip sub-directories
            FileInputStream in = new FileInputStream(f); // Stream to read file
            ZipEntry entry = new ZipEntry(f.getPath( ));  // Make a ZipEntry
            out.putNextEntry(entry);                     // Store entry
            while((bytes_read = in.read(buffer)) != -1)  // Copy bytes
                out.write(buffer, 0, bytes_read);
            in.close( );                                  // Close input stream
        }
        // When we're done with the whole loop, close the output stream
        out.close( );
    }