使用Commons-compression读取Java中的tar.gz

好的,我想阅读tar.gz文件(或xy)的内容,但这是一回事.我正在做的或多或少是这样的:

TarArchiveInputStream tarInput = new TarArchiveInputStream(new GzipCompressorInputStream(new FileInputStream("c://temp//test.tar.gz")));
TarArchiveEntry currentEntry = tarInput.getNextTarEntry();
BufferedReader br = null;
StringBuilder sb = new StringBuilder();
while (currentEntry != null) {
    File f = currentEntry.getFile();
    br = new BufferedReader(new FileReader(f));
    System.out.println("For File = " + currentEntry.getName());
    String line;
    while ((line = br.readLine()) != null) {
        System.out.println("line="+line);
    }
}
if (br!=null) {
    br.close();
}

但是当我调用getFile方法时,我得到null TarArchiveEntry.
我正在使用Apache commons compress 1.8.1