Apache在Commons Compress简介和简单应用，commonscompress,Apache在Commo

Apache在Commons Compress简介和简单应用，commonscompress,Apache在Commo

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.jarpackagetest.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