test.txt

package net.mindview.util;

import java.io.*;
import java.util.*;

/**
 * RUN:
 *         javac net/mindview/util/TextFile.java
 *         
 * OUTPUT:
 *         
 */

public class TextFile extends ArrayList<String> {

    public static String read(String fileName) {
        
        StringBuilder sb = new StringBuilder();
        
        try {
            BufferedReader in = new BufferedReader(
                new FileReader(
                    new File(fileName).getAbsoluteFile()
                )
            );

            try {
                String s;
                while ((s = in.readLine()) != null) {
                    sb.append(s);
                    sb.append("\n");
                }
            }
            finally {
                in.close();
            }
        }
        catch (IOException e) {
            throw new RuntimeException(e);
        }

        return sb.toString();
    }

    public static void write(String fileName, String text) {
        try {
            PrintWriter out = new PrintWriter(
                new File(fileName).getAbsoluteFile()
            );

            try {
                out.print(text);
            }
            finally {
                out.close();
            }
        }
        catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public TextFile(String fileName, String splitter) {
        super(Arrays.asList(read(fileName).split(splitter)));
        if (get(0).equals("")) {
            remove(0);
        } 
    }

    public TextFile(String fileName) {
        this(fileName, "\n");
    }

    public void write(String fileName) {
        try {
            PrintWriter out = new PrintWriter(
                new File(fileName).getAbsoluteFile()
            );
            try {
                for (String item : this) {
                    out.println(item);
                }
            }
            finally {
                out.close();
            }
        }
        catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public static void main(String[] args) {
        
        String fileName = "net/mindview/util/TextFile.java";
        
        String file = read(fileName);
        write("test.txt", file);

        TextFile text = new TextFile("test.txt");
        text.write("test2.txt");

        TreeSet<String> words = new TreeSet<String>(new TextFile(fileName, "\\W+"));
        System.out.println(words.headSet("a"));
    }
}