java - 使用 Commons-compression 在 Java 中读取 tar.gz

Question

好的，所以我想读取 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 TarArchiveEntry 的 getFile 方法时，我得到的是 null。
我正在使用 Apache commons compress 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"file"的内容返回给您并即时解压缩。

例如(未经测试的代码，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
}