AVAJAVA Web Tutorials

The PrefixFileFilter in the ApacheSW Commons IOS library makes it easy to filter files to obtain files with a particular prefix. This can be done using case sensitivity or case insensitivity. The PrefixFileFilterTest class demonstrates calling a directory's listFiles() method with PrefixFileFilter objects serving as filters.

PrefixFileFilterTest.java

package test;

import java.io.File;
import java.io.FileFilter;
import java.io.IOException;

import org.apache.commons.io.IOCase;
import org.apache.commons.io.filefilter.PrefixFileFilter;

public class PrefixFileFilterTest {

	public static void main(String[] args) throws IOException {
		File directory = new File(".");

		File[] files = directory.listFiles();
		System.out.println("All files and directories:");
		displayFiles(files);

		System.out.println("\nFiles beginning with 'Test' (case sensitive):");
		files = directory.listFiles((FileFilter) new PrefixFileFilter("Test", IOCase.SENSITIVE));
		displayFiles(files);

		System.out.println("\nFiles beginning with 'Test' (case insensitive):");
		files = directory.listFiles((FileFilter) new PrefixFileFilter("Test", IOCase.INSENSITIVE));
		displayFiles(files);

	}

	public static void displayFiles(File[] files) {
		for (File file : files) {
			System.out.println(file.getName());
		}
	}

}

The PrefixFileFilterTest class first displays all files in my project's root directory. After that, it displays all files beginning with "Test" with case sensitivity. Finally, it displays all files beginning with "Test" but with case insensitivity.

Results

All files and directories:
.classpath
.project
bin
docs
lib
src
Test1.txt
test2.txt
Test3.txt
test4.txt

Files beginning with 'Test' (case sensitive):
Test1.txt
Test3.txt

Files beginning with 'Test' (case insensitive):
Test1.txt
test2.txt
Test3.txt
test4.txt