Java Wget Bz2 文件

Question

我正在尝试从维基百科获取一些 bz2 文件，我不在乎它们是保存为 bz2 还是解压，因为我可以在本地解压它们。

当我打电话时:

public static void getZip(String theUrl, String filename) throws IOException {
    URL gotoUrl = new URL(theUrl);
    try (InputStreamReader isr = new InputStreamReader(new BZip2CompressorInputStream(gotoUrl.openStream())); BufferedReader in = new BufferedReader(isr)) {
        StringBuffer sb = new StringBuffer();
        String inputLine;

        // grab the contents at the URL
        while ((inputLine = in.readLine()) != null) {
            sb.append(inputLine + "\r\n");
        }
        // write it locally
        Wget.createAFile(filename, sb.toString());
    } catch (MalformedURLException mue) {
        mue.printStackTrace();
    } catch (IOException ioe) {
        throw ioe;
    }
}

我得到了解压文件的一部分，不超过 +- 883K。
当我不使用 BZip2CompressorInputStream 时，例如:

public static void get(String theUrl, String filename) throws IOException {
    try {
        URL gotoUrl = new URL(theUrl);
        InputStreamReader isr = new InputStreamReader(gotoUrl.openStream());
        BufferedReader in = new BufferedReader(isr);

        StringBuffer sb = new StringBuffer();
        String inputLine;

        // grab the contents at the URL
        while ((inputLine = in.readLine()) != null) {
            sb.append(inputLine);// + "\r\n");
        }
        // write it locally
        Statics.writeOut(filename, false, sb.toString());
    } catch (MalformedURLException mue) {
        mue.printStackTrace();
    } catch (IOException ioe) {
        throw ioe;
    }
}

我得到一个文件，其大小与预期相同(与 KB 相比，而不是 B)。但当使用 byte [] 而不是 readLine() 时，也会显示压缩文件已损坏的消息，例如:

public static void getBytes(String theUrl, String filename) throws IOException {
    try {
        char [] cc = new char[1024];
        URL gotoUrl = new URL(theUrl);
        InputStreamReader isr = new InputStreamReader(gotoUrl.openStream());
        BufferedReader in = new BufferedReader(isr);

        StringBuffer sb = new StringBuffer();
        // grab the contents at the URL
        int n = 0;
        while (-1 != (n = in.read(cc))) {
            sb.append(cc);// + "\r\n");
        }
        // write it locally
        Statics.writeOut(filename, false, sb.toString());
    } catch (MalformedURLException mue) {
        mue.printStackTrace();
    } catch (IOException ioe) {
        throw ioe;
    }
}

最后，当我对 inputstream 和 outputstream 进行 bzip2 时，我得到了一个有效的 bzip2 文件，但其大小与第一个文件相同，使用:

public static void getWriteForBZ2File(String urlIn, final String filename) throws CompressorException, IOException {
    URL gotoUrl = new URL(urlIn);
    try (final FileOutputStream out = new FileOutputStream(filename);
            final BZip2CompressorOutputStream dataOutputStream = new BZip2CompressorOutputStream(out);
            final BufferedInputStream bis = new BufferedInputStream(gotoUrl.openStream());
            final CompressorInputStream input = new CompressorStreamFactory().createCompressorInputStream(bis);
            final BufferedReader br2 = new BufferedReader(new InputStreamReader(input))) {
        String line = null;
        while ((line = br2.readLine()) != null) {
            dataOutputStream.write(line.getBytes());
        }
    }
}

那么，如何获取整个 bz2 文件(采用 bz2 格式或解压后的格式)？

Answer 1

bz2 文件包含字节，而不是字符。您无法使用阅读器将其视为包含字符来读取。

由于您要做的只是下载文件并将其保存在本地，因此您所需要的就是

Files.copy(gotoUrl.openStream(), Paths.get(fileName));