JZOO - Wild Card Filter

Wild Card Filter

Example
See below

About
This is utility code for use by Java programmers; Java provides an abstract class called a FilenameFilter and is used when you want to use wildcard characters when specifying filenames.

Examples:


            *.java

            in*.log

            data*.*

No implementation of this class is provided in the JDK. This program provides a sample of how you might code a FilenameFilter.

JDK Bug

The FilenameFilter was designed to be used with a FileDialog. Unfortunately, this is not supported on most platforms. i.e. A FilenameFilter will not work with a FileDialog. This has been listed as Bug ID 4031440 on the Java Developer Connection site (you need to be a registered user to visit here).

Extract from Sun's response to this bug:

The main issue is that support for FilenameFilter in the FileDialog class was never implemented on any platform -- it's not that there's a bug which needs to be fixed, but that there's no code to run nor was the design ever evaluated to see if it *could* be implemented on our target platforms. ... Unfortunately this is not going to get addressed for 1.2, other than having people use Swing's JFileChooser.

You may download simple hack (fdhack.java) which I understand will work on some platforms. This uses the call such as

fd.setFile("*.java");

(where fd is a FileDialog) to list all files ending with '.java'. No FilenameFilter is used here.

Source

Java Files	Class Files	Zip Files
JZOOWildCardFilter.java dir.java	JZOOWildCardFilter.class dir.class	jzoowildcardfilter.zip
Copy the .java and .class files to a directory and type: `java dir "*.java"` (for example) to run the sample program.

Parameters
None

Usage Example

import java.io.File;

public class dir
{
    public static void main(String[] args)

    {
        // check args

        if (args.length != 1)
        {
            System.out.println("usage: java dir \"<wildcard>\"");
            return;
        }

        JZOOWildCardFilter filter = new JZOOWildCardFilter(args[0]);

        System.out.println("Internal structure:");
        System.out.println("  toString: " + filter.toString());
        System.out.println("  toPattern: " + filter.toPattern());
        System.out.println("Directory listing:");

        File currDir = new File(".");
        String files[] = currDir.list(filter);

        if (files.length == 0)
        {
            System.out.println("  No files match " + filter);
        }
        else
        {
            for (int i=0; i<files.length; i++)
            {
                System.out.println("  " + files[i]);
            }
        }
    }
}

This example is found in the file dir.java

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