Mine

package com.cp.brainfuck;import java.util.Stack;import java.util.EmptyStackException;import java.util.ArrayList;import com.cp.ircbot.bot.IRCBot;public class BrainfuckInterpreter{    private ArrayList<BrainfuckThread> threads;    private IRCBot bot;    public BrainfuckInterpreter(IRCBot bot)    {        this.bot = bot;        threads = new ArrayList<BrainfuckThread>();    }    public ArrayList<String> cleanup()    {        ArrayList<BrainfuckThread> toRemove = new ArrayList<BrainfuckThread>();        ArrayList<String> output = new ArrayList<String>();        for (BrainfuckThread thread : threads)        {            if (!thread.isRunning())                toRemove.add(thread);        }        for (BrainfuckThread thread : toRemove)        {            if (!thread.getOutput().getOutput().equals(""))            {                output.add(thread.getOutput().getOutput());            }        }        threads.removeAll(toRemove);        return output;    }    public BrainfuckThread execute(String brainfuck) throws BrainfuckParseError    {        return execute(brainfuck.toCharArray());    }    public BrainfuckThread execute(char[] brainfuck) throws BrainfuckParseError    {        char[] segments = parse(brainfuck);        BrainfuckThread thread = new BrainfuckThread(brainfuck, segments, new BrainfuckWriter());        threads.add(thread);        return thread;    }    private char[] parse(char[] brainfuck) throws BrainfuckParseError    {        char[] codeStack = new char[brainfuck.length];        Stack<Integer> stack = new Stack<Integer>();        for (int index = 0; index < brainfuck.length; index++)        {            switch (brainfuck[index])            {                case '[':                    stack.push(index);                    break;                case ']':                    try                    {                        int x = stack.pop();                        codeStack[x] = (char) index;                        codeStack[index] = (char) x;                    } catch (EmptyStackException e)                    {                        throw new BrainfuckParseError("Unbalanced brackets");                    }                    break;            }        }        if (!stack.isEmpty())            throw new BrainfuckParseError("Unclosed bracket");        return codeStack;    }}