Java Wget Bz2文件

时间:2015-08-15 11:32:34

标签: java webget bz2

我试图从维基百科中搜索一些bz2文件,我不在乎它们是保存为bz2还是解压缩,因为我可以在本地解压缩它们。

我打电话的时候:

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;
    }
}

我得到解压缩文件的一部分,从不超过+ - 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;
    }
}

我得到一个大小与它想象的相同的文件(与KB而不是B相比)。但是,当使用byte []代替readLine()时,也会发出拉链文件损坏的消息,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bzip2 inputstreamoutputstream时,我得到一个有效的bzip2文件,但大小与第一个一样,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格式获取整个bz2文件或解压缩?

1 个答案:

答案 0 :(得分:2)

bz2文件包含字节,而不是字符。您无法使用Reader读取它,就好像它包含字符一样。

由于您只想下载文件并将其保存在本地,因此您只需要

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