数据压缩案例

TestCompress

public class TestCompress {

    public static void main(String[] args) throws Exception {

        // 压缩

        compress("e:/hello.txt", "org.apache.hadoop.io.compress.BZip2Codec");

        //compress("e:/hello.txt", "org.apache.hadoop.io.compress.Gzipcodec");

        //compress("e:/hello.txt", "org.apache.hadoop.io.compress.DefaultCodec");

    }

    private static void compress(String fileName, String method) throws Exception {

        // 1 获取输入流

        FileInputStream fis = new FileInputStream(new File(fileName));

        // 2 获取输出流

        Class classCodec = Class.forName(method);

        CompressionCodec codec = (CompressionCodec) ReflectionUtils.newInstance(classCodec, new Configuration());

        FileOutputStream fos = new FileOutputStream(new File(fileName + codec.getDefaultExtension()));

        CompressionOutputStream cos = codec.createOutputStream(fos);

        // 3 流的对拷

        IOUtils.copyBytes(fis, cos, 1024 * 1024, false);

        // 4 关闭资源

        IOUtils.closeStream(cos);

        IOUtils.closeStream(fos);

        IOUtils.closeStream(fis);

    }

}