How to zip only .txt files using java

Question

package codes;

import java.io.File;
import java.io.FileOutputStream;
import java.io.FilenameFilter;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

public class Rough {


public static void main(String[] args) throws IOException {
private static final String FOLDER_PATH = "C:\\Users\\s13w63\\Desktop\\Zip";    

File dir = new File(FOLDER_PATH);

    File[] files = dir.listFiles(new FilenameFilter() {

        @Override
        public boolean accept(File directory, String fileName) {
            if (fileName.endsWith(".txt")) {
                return true;
            }
            return false;
        }
    });


    for (File f : files)
    {
        FileOutputStream fos=new FileOutputStream("C:\\Users\\s13w63\\Desktop\\Source.zip");
        ZipOutputStream zos=new ZipOutputStream(fos);
        ZipEntry ze=new ZipEntry(f.getCanonicalPath());
        zos.putNextEntry(ze);
        zos.close();
        System.out.println(f.getCanonicalPath());
    }
}
}

I tried this code to ZIP the files, it was showing the file names but not zipping them. Should I have to add anything..and it was showing there is error in code continue to compile??

Help me to solve this issue

possible duplicate of [Java - How to move a file into a zip file?](http://stackoverflow.com/questions/11905982/java-how-to-move-a-file-into-a-zip-file) — default locale, Jan 19 '15 at 08:05
You're calling `ZipEntry(name)`. This code creates an entry with particular name. It doesn't actually write anything to zip file. Check out linked question to learn how to write contents of zip file. — default locale, Jan 19 '15 at 08:08
@defaultlocale the solution in the linked question is obsolete; since Java 7+ you have a zip `FileSystem` available — fge, Jan 19 '15 at 08:09
@fge solution is still usable, though. Also linked question is still open so you can post new answer there. I'll be happy to upvote. — default locale, Jan 19 '15 at 08:11
@defaultlocale the problem in this question is different since here there are several files to move; and here again, there is a cleaner solution than using a `FilenameFilter`. See my answer for more details. — fge, Jan 19 '15 at 08:16

fge · Answer 1 · 2015-01-19T08:30:09.400

Use java.nio.file; it has a very nice solution to your problem.

Illustration:

final Path zipPath = Paths.get("C:\\Users\\s13w63\\Desktop\\Source.zip");

final Path dir = Paths.get("C:\\Users\\s13w63\\Desktop\\Zip");
final DirectoryStream<Path> dirstream
    = Files.newDirectoryStream(dir, "*.txt");

final URI uri = URI.create("jar:" + zipPath.toUri());
final Map<String, ?> env = Collections.emptyMap();

String filename;

try (
    final FileSystem zipfs = FileSystems.newFileSystem(uri, env);
) {
    for (final Path entry: dirstream) {
        filename = dir.relativize(entry).toString();
        Files.copy(entry, zipfs.getPath("/" + filename));
    }
}

Yes, that's right, you can open a zip file as a FileSystem; as such, every operation in Files can be used "on a zip"!

This is JSR 203 for you; you even have FileSystem implementations in memory, over FTP, Dropbox, and others.

Note about the necessity to have the file name as a String: it is because you cannot .resolve() a Path against another if the other Path is from a different provider; I have published a package which solves this particular problem (among others) and has a MorePaths.resolve() method for such cases.

Balaji Katika · Accepted Answer · 2015-01-19T08:45:00.483

Bharat, Please paste the error message that you see

Also, I see few issues with your approach. You might need to do the below things

Take out the definition of FOS and ZOS from the for loop and move it above it...
The code to add the file is missing...
Move zos.close() after the for loop
You could use the below code to add contents of the text file to the ZipOutputStream

/**
* Adds a file to the current zip output stream
* 
* @param file
*            the file to be added
* @param zos
*            the current zip output stream
*/

private static void addFileToZip(File file, ZipOutputStream zos) {
        try (BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file))) {
                 zos.putNextEntry(new ZipEntry(file.getName()));
                 byte[] bytesIn = new byte[BUFFER_SIZE];
                 int read = 0;

         while ((read = bis.read(bytesIn)) != -1) {
             zos.write(bytesIn, 0, read);
         }
         zos.closeEntry();
     } catch (IOException e) {
             //Take appropriate action
     }
 }

How to zip only .txt files using java

2 Answers2