Apache在Commons Compress简介和简单应用详解编程语言

Apache在CommonsCompress中提供了众所周知的tar、cpio、zip等压缩算法实现，其中最为丰富的当属zip实现了！

Commons Compress为压缩（GZip和BZip2）构建了压缩算法工厂类CompressorStreamFactory。通过这个类可以方便的构建GZip和BZip2的输入输出流，关键字分别为“gz”和“bzip2”。 
GZip 

Java代码  
 
//GzipCompressorInputStream        
 
    CompressorInputStream gzipIn = newCompressorStreamFactory()  
 
            .createCompressorInputStream("gz",is);  
 
      
 
    // GzipCompressorOutputStream  
 
    CompressorOutputStream gzipOut = newCompressorStreamFactory()  
 
           .createCompressorOutputStream("gz", os); 
 
  
 
BZip2  
 
Java代码  
 
// BZip2CompressorInputStream  
 
    CompressorInputStream bzip2In =new CompressorStreamFactory()  
 
           .createCompressorInputStream("bzip2", is);  
 
      
 
    //BZip2CompressorOutputStream  
 
    CompressorOutputStream bzip2Out= new CompressorStreamFactory()  
 
           .createCompressorOutputStream("bzip2", os);  
 
  
 
下面是一个完整的通过apachecommons compress简单实现bzip2压缩的样例。 
 
需要导入的包为：commons-compress-1.9.jar 
 
packagetest.ffm83.commons.compress; 
 
  
 
importjava.io.ByteArrayInputStream;  
 
importjava.io.ByteArrayOutputStream;  
 
importjava.io.File;  
 
importjava.io.FileInputStream;  
 
importjava.io.FileOutputStream;  
 
importjava.io.InputStream;  
 
importjava.io.OutputStream;  
 
  
 
importorg.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream; 
 
importorg.apache.commons.compress.compressors.bzip2.BZip2CompressorOutputStream; 
 
/* 通过apache commons compress简单实现bzip2压缩 
 
 * 部分代码来自互联网 
 
 * @author 范芳铭 
 
 * */ 
 
publicclass BZip2Utils { 
 
    public static final int BUFFER = 1024;  
 
    public static final CharSequence EXT =".bz2";  
 
  
 
    /** 
 
     * 数据压缩 
 
     *  
 
     * @param data 
 
     * @return 
 
     * @throws Exception 
 
     */  
 
    public static byte[] compress(byte[] data)throws Exception {  
 
        ByteArrayInputStream bais = newByteArrayInputStream(data);  
 
        ByteArrayOutputStream baos = newByteArrayOutputStream();  
 
  
 
        // 压缩  
 
        compress(bais, baos);  
 
  
 
        byte[] output =baos.toByteArray();  
 
  
 
        baos.flush();  
 
        baos.close();  
 
  
 
        bais.close();  
 
  
 
        return output;  
 
    }  
 
    
 
    /** 
 
     * 文件压缩 
 
     *  
 
     * @param file 
 
     * @param delete 
 
     *            是否删除原始文件 
 
     * @throws Exception 
 
     */  
 
    public static void compress(File file,boolean delete) throws Exception {  
 
        FileInputStream fis = newFileInputStream(file);  
 
        FileOutputStream fos = newFileOutputStream(file.getPath() + EXT);  
 
  
 
        compress(fis, fos);  
 
  
 
        fis.close();  
 
        fos.flush();  
 
        fos.close();  
 
  
 
        if (delete) {  
 
            file.delete();  
 
        }  
 
    }  
 
  
 
    /** 
 
     * 数据压缩 
 
     *  
 
     * @param is 
 
     * @param os 
 
     * @throws Exception 
 
     */  
 
    public static void compress(InputStream is,OutputStream os)  
 
            throws Exception {  
 
  
 
        BZip2CompressorOutputStream gos = newBZip2CompressorOutputStream(os);  
 
  
 
        int count;  
 
        byte data[] = new byte[BUFFER];  
 
        while ((count = is.read(data, 0, BUFFER)) !=-1) {  
 
            gos.write(data, 0, count);  
 
        }  
 
        gos.finish();  
 
        gos.flush();  
 
        gos.close();  
 
    }  
 
  
 
    /** 
 
     * 文件压缩 
 
     *  
 
     * @param path 
 
     * @param delete 
 
     *            是否删除原始文件 
 
     * @throws Exception 
 
     */  
 
    public static void compress(String path,boolean delete) throws Exception {  
 
        File file = new File(path);  
 
        compress(file, delete);  
 
    }  
 
  
 
    /** 
 
     * 数据解压缩 
 
     *  
 
     * @param data 
 
     * @return 
 
     * @throws Exception 
 
     */  
 
    public static byte[] decompress(byte[]data) throws Exception {  
 
        ByteArrayInputStream bais = newByteArrayInputStream(data);  
 
        ByteArrayOutputStream baos = newByteArrayOutputStream();  
 
  
 
        // 解压缩  
 
  
 
        decompress(bais, baos);  
 
  
 
        data = baos.toByteArray();  
 
  
 
        baos.flush();  
 
        baos.close();  
 
  
 
        bais.close();  
 
  
 
        return data;  
 
    }  
 
   
 
    /** 
 
     * 文件解压缩 
 
     *  
 
     * @param file 
 
     * @param delete 
 
     *            是否删除原始文件 
 
     * @throws Exception 
 
     */  
 
    public static void decompress(File file,boolean delete) throws Exception {  
 
        FileInputStream fis = newFileInputStream(file);  
 
        FileOutputStream fos = newFileOutputStream(file.getPath().replace(EXT,  
 
                ""));  
 
        decompress(fis, fos);  
 
        fis.close();  
 
        fos.flush();  
 
        fos.close();  
 
  
 
        if (delete) {  
 
            file.delete();  
 
        }  
 
    }  
 
  
 
    /** 
 
     * 数据解压缩 
 
     *  
 
     * @param is 
 
     * @param os 
 
     * @throws Exception 
 
     */  
 
    public static void decompress(InputStreamis, OutputStream os)  
 
            throws Exception {  
 
  
 
        BZip2CompressorInputStream gis = newBZip2CompressorInputStream(is);  
 
  
 
        int count;  
 
        byte data[] = new byte[BUFFER];  
 
        while ((count = gis.read(data, 0,BUFFER)) != -1) {  
 
            os.write(data, 0, count);  
 
        }  
 
  
 
        gis.close();  
 
    }  
 
  
 
    /** 
 
     * 文件解压缩 
 
     *  
 
     * @param path 
 
     * @param delete 
 
     *            是否删除原始文件 
 
     * @throws Exception 
 
     */  
 
    public static void decompress(String path,boolean delete) throws Exception {  
 
        File file = new File(path);  
 
        decompress(file, delete);  
 
    }  
 
    
 
  
 
    public static void main(String[] args)throws Exception{ 
 
        StringinputStr = "http://blog.csdn.net/ffm83/article/details/42240513"; 
 
        
 
        byte[]input = inputStr.getBytes();  
 
        System.out.println("原文:/t" + inputStr);  
 
        System.out.println("长度:/t" + input.length);  
 
        
 
        byte[] data = compress(input);  
 
        System.err.println("压缩后:/t");  
 
        System.err.println("长度:/t" + data.length);  
 
  
 
        byte[] output =  decompress(data);  
 
        String outputStr = newString(output);  
 
        System.err.println("解压缩后:/t" + outputStr);  
 
        System.err.println("长度:/t" + output.length); 
 
    } 
 
}

运行结果如下：

原文:   http://blog.csdn.net/ffm83/article/details/42240513

长度:   51

压缩后:

长度:   86

解压缩后:   http://blog.csdn.net/ffm83/article/details/42240513

长度:   51