how to copy files at runtime

[mythily prakash]

hi,
i've to copy all the files in one directory to some other dir.
I can copy the files if and only if i know the filename and its extension.I may know the dir exactly but not the files inside and these files are with different extension.This program will have to work in java1.3,1.4 & 1.5 also.Pls help me to get it rite way.

[Ben Cramphorn]

Hello.

Try looking up file.list() on the API.

[mythily prakash]

Thanks Ben Cramphorn.

I can do it with the following code:

// Copies all files under srcDir to dstDir.
    // If dstDir does not exist, it will be created.
    public void copyDirectory(File srcDir, File dstDir) throws IOException {
        if (srcDir.isDirectory()) {
            if (!dstDir.exists()) {
                dstDir.mkdir();
            }
    
            String[] children = srcDir.list();
            for (int i=0; i<children.length; i++) {
                copyDirectory(new File(srcDir, children[i]),
                                     new File(dstDir, children[i]));
            }
        } else {
            copyFile(srcDir, dstDir);
        }
    }
 
// Copies src file to dst file.
    // If the dst file does not exist, it is created
    void copy(File src, File dst) throws IOException {
        InputStream in = new FileInputStream(src);
        OutputStream out = new FileOutputStream(dst);
    
        // Transfer bytes from in to out
        byte[] buf = new byte[1024];
        int len;
        while ((len = in.read(buf)) > 0) {
            out.write(buf, 0, len);
        }
        in.close();
        out.close();
    }

[Ben Cramphorn]

No worries.

[Tony Morris]

If you are targetting 1.4 or higher, you may want to consider using java.nio and obtain performance benefits (I cannot prove this - hearsay).