Java-从网站压缩文件？

Question

I just wanted to know how can I zip a file on the web using java, of course.

I know how to do this for directories on the hard drive, but not for websites:

ZipFile zipfile = new ZipFile("C:/Documents and Settings/User/desktop/something.file");

Thank you very much.

Answer 1

So I take it that you want to download and compress a file. That's two different tasks, so you need two things to do it:

• something to download the file from the web
• something to compress it into a zip file

I suggest that you use Apache HttpComponents to download the file, and Apache Compress to compress it.

Then the code would go something like this...

    // Obtain reference to file
    HttpGet httpGet = new HttpGet("http://blahblablah.com/file.txt");
    HttpResponse httpResponse = httpclient.execute(httpGet);
    HttpEntity httpEntity = httpResponse.getEntity();

    // Create the output ZIP file
    ZipArchiveOutputStream zip = new ZipArchiveOutputStream(zipFile);

    try {
        // Write a file header in the .zip file
        ArchiveEntry entry = new ZipArchiveEntry("file.txt");
        zip.putArchiveEntry(entry);

        // Download the file and write it to a compressed file
        IOUtils.copy(httpEntity.getContent(), zip);

        // The file is now written
        zip.closeArchiveEntry();
    } finally {
        // Ensure output file is closed
        zip.close();
    }

How does it work? HttpComponents is obtaining an InputStream of the file, and Compress is providing an OutputStream . Then you're just copying from one stream into the other. It's like magic!

Answer 2

It's the same but you have to use a couple of methods:

String filePath = getServletContext().getRealPath("/WEB-INF/your_folder/your_file");

filepath is the absolute filesystem path (C:/.../WEB-INF/your_folder/your_file)

Answer 3

By 'zip a file on the web' it sounds like you mean doing so programatically within code in a web or application server.

This page may help. It discusses how to use the java.util.zip package: http://java.sun.com/developer/technicalArticles/Programming/compression/