Java wget Bz2文件

Question

我正在尝试从维基百科获取一些 bz2 文件，我不关心它们是保存为 bz2 还是解压，因为我可以在本地解压缩它们。

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;
    }
}

我得到了解压缩文件的一部分，不会超过 +- 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，其大小与预期的大小相同（与 KB 而不是 B 相比）。但还有一条消息表明压缩文件已损坏，同样在使用 byte [] 而不是 readLine() 时，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 bzip2 inputstream 和 outputstream 时，我得到了一个有效的 bzip2 文件，但大小与第一个文件一样，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，如何以 bz2 格式或解压得到整个 bz2 文件？

Answer 1

bz2 文件包含字节，而不是字符。你不能阅读它，就好像它包含字符一样，带有 Reader.

既然您只想下载文件并保存在本地，那么您只需要

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

Java wget Bz2文件

Java Wget Bz2 file

java

webget

bz2