Question

What I am trying to do is copy files from one folder to another. However, the twist is i was to copy all files from one folder which begin with say 123 and anything can follow.

For example i have a folder with 3 files, 123__sdf.jpg, 123034.jpg and 321.jpg.
I only want to copy the first two but how do I select them only. Because this application is dynamic the files can change thats why i only want to be able to select all files which begin with 123.

Answer 1

First, you want to create a file pointing to the directory. Then, you can use the list method to get the list of files inside the directory. You can then use startsWith to check whether they start with 123 or not.

File dir = new File("/the/dir/");
if( dir.isDirectory() ){
    String[] files = dir.list();
    for (String string : files) {
        if( string.startsWith("123") ){
            File file = new File(dir, string);
            // do the copy stuff
        }
    }
}

list method returns a list of strings with files and directories, so you may want to use the isFile() method if you only want to copy files.