This program helps to choose a volunteer from a list of students.

ParticipantSelector.java

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class ParticipantSelector {

	private static final String FILE_NAME = "students.txt";
	private static BufferedReader br;
	private static String option = "l";

	private static String getNextOption() {
		String result = "";
		System.out.println("Enter an option:");
		try {
			result = br.readLine();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return "".equals(result.trim()) ? option : result.trim().toLowerCase();
	}

	private static List<String> getParticipants() {
		List<String> result = new ArrayList<String>();
		String line;

		try {
			br = new BufferedReader(new FileReader(FILE_NAME));
			while ((line = br.readLine()) != null) {
				result.add(line);
			}
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				br.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}

		return result;
	}

	public static void main(String[] args) throws FileNotFoundException {
		List<String> list = getParticipants();

		String currentParticipant;
		br = new BufferedReader(new InputStreamReader(System.in));
		do {
			option = getNextOption();
			switch (option) {
			case "n":
				currentParticipant = list.remove((int) (Math.random() * (list
						.size())));
				System.out.println(currentParticipant);
				break;
			case "l":
				System.out.println(list);
				break;
			case "q":
				return;
			}
		} while (!"q".equalsIgnoreCase(option) && !list.isEmpty());
	}

}