使用Commons压缩在Java中读取tar.gz

Question

我想读取一个thing文件(或者一个xy文件)的内容，但这是一回事。我所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TarArchiveEntry的getFile方法时，我得到null。
我正在使用Apache公共压缩1.8.1

Answer 1

您不能使用TarArchiveEntry的getFile。当您在tar文件中压缩文件时，该getter仅用于相反的操作。

相反，您应该直接从TarArchiveInputStream读取。它会负责将“文件”的内容动态地解压缩并返回给你。

例如（未测试代码，YMMV）：

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) {
    br = new BufferedReader(new InputStreamReader(tarInput)); // Read directly from tarInput
    System.out.println("For File = " + currentEntry.getName());
    String line;
    while ((line = br.readLine()) != null) {
        System.out.println("line="+line);
    }
    currentEntry = tarInput.getNextTarEntry(); // You forgot to iterate to the next file
}