HSPAL Interpreter

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

public class HSPAL {
    static int register=0;
    static Random r=new Random();
    static List<Stack<Integer>> stacks=new ArrayList<Stack<Integer>>()
            {
                private static final long serialVersionUID = 1L;

            {
                for(int i=0;i<=255;i++)add(new Stack<Integer>());
            }};
    static Map<Integer,Integer> checkpoints=new HashMap<Integer,Integer>();
    public static int status=0;
    @SuppressWarnings("resource")
    public static void main(String[] a) throws IOException{
        PrintStream error=new PrintStream("error.txt");
        try{String lastInput="";
        String s1=a.length>=1?a[0]:"code.txt";
        File k=new File(s1);
        String s2=a.length>=2?a[1]:"input.txt";
        String s3=a.length>=3?a[2]:"output.txt";
        (new File(s3)).createNewFile();
        (new File(s2)).createNewFile();
        Scanner input=new Scanner(new File(s2));
        PrintStream output=new PrintStream(s3);
        k.createNewFile();
        BufferedReader reader=new BufferedReader(new FileReader(k));
        List<String> commands=new ArrayList<String>();
        String c=reader.readLine();
        int line=0;
        while(c!=null){
            line++;
            if(c.length()%6!=0)throw new IllegalArgumentException("Invalid syntax on line "+line+", the length of each line must be a multiple of six.");
            if(c.length()==0){continue ;}
            for(int x=0;x<c.length()/6;x++){
                String command=c.substring(6*x, 6*(x+1));
                try{Integer.parseInt(command,16);}catch(Exception e){throw new IllegalArgumentException("Invalid syntax on line "+line+", each command must be a valid base-16 integer.");}
                commands.add(command);
            }
            c=reader.readLine();
        }
        for(int x=0;x<commands.size();x++){
            String command=commands.get(x);
            if(command.substring(0, 2).equals("00")){
                int key=Integer.parseInt(command.substring(2,6),16);
                if(checkpoints.get(key)!=null)throw new IllegalArgumentException("Duplicate checkpoint on line "+(x+1));
                checkpoints.put(key,x);
            }
        }
        for(int x=0;x<commands.size();x++){
            String command=commands.get(x);
            if(command.substring(0, 2).equals("01")){
                Integer y=checkpoints.get(Integer.parseInt(command.substring(2,6),16));
                if(y==null)throw new IllegalArgumentException("Invalid checkpoint!");
                x=y;
            }
            else if(command.substring(0, 2).equals("02")){
                int stackAddress=Integer.parseInt(command.substring(2,4),16);
                Integer y=checkpoints.get(stacks.get(stackAddress).pop());
                if(y==null)throw new IllegalArgumentException("Invalid checkpoint!");
                x=y;
            }
            else if(command.substring(0, 2).equals("03")){
                int stackAddress=Integer.parseInt(command.substring(2,4),16);
                Integer y=stacks.get(stackAddress).pop();
                if(y!=0)x++;
            }
            else if(command.substring(0, 2).equals("04")){
                status=Integer.parseInt(command.substring(2,6),16);
                break ;
            }
            else if(command.substring(0, 2).equals("10")){
                int stackAddress=Integer.parseInt(command.substring(2,4),16);
                if(lastInput.length()==0){
                    if(input.hasNext()){lastInput=input.nextLine();}else{stacks.get(stackAddress).push(0);continue ;};
                }
                stacks.get(stackAddress).push((int)lastInput.charAt(0));
                lastInput=lastInput.substring(1);
            }
            else if(command.substring(0, 2).equals("11")){
                int stackAddress=Integer.parseInt(command.substring(2,4),16);
                int value=input.hasNext()?input.nextInt():0;
                if(value<0)throw new IllegalArgumentException();
                stacks.get(stackAddress).push(value);
            }
            else if(command.substring(0, 2).equals("12")){
                int stackAddress=Integer.parseInt(command.substring(2,4),16);
                int m;
                Stack<Integer> stack=stacks.get(stackAddress);
                try{m=stack.pop();}catch(Exception e){throw new Exception("Empty stack exception on line "+(x+1));}
                output.println(m);
            }
            else if(command.substring(0, 2).equals("13")){
                int stackAddress=Integer.parseInt(command.substring(2,4),16);
                int charCode=stacks.get(stackAddress).pop();
                if(charCode==0){
                    output.println();
                }else{
                    output.print((char)charCode);
                }
            }
            else if(command.substring(0, 2).equals("14")){
                int stackAddress=Integer.parseInt(command.substring(2,4),16);
                Stack<Integer> stack=stacks.get(stackAddress);
                while(stack.size()!=0){
                    int charCode=stacks.get(stackAddress).pop();
                    if(charCode==0){
                        output.println();
                    }else{
                        output.print((char)charCode);
                    }
                }
            }
            else if(command.substring(0, 2).equals("20")){
                register=Integer.parseInt(command.substring(2,6),16);
            }
            else if(command.substring(0, 2).equals("21")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                int m=stack.pop(),n=stack.pop();
                stack.push(Math.min(m+n,65535));
            }
            else if(command.substring(0, 2).equals("22")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                int m=stack.pop(),n=stack.pop();
                stack.push(Math.max(0, m-n));
            }
            else if(command.substring(0, 2).equals("23")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                int m=stack.pop(),n=stack.pop();
                stack.push(Math.min(m*n,65535));
            }
            else if(command.substring(0, 2).equals("24")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                int m=stack.pop(),n=stack.pop();
                stack.push(m/n);
            }
            else if(command.substring(0, 2).equals("25")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                int m=stack.pop(),n=stack.pop();
                stack.push((int)Math.min((long)Math.pow(m, n),65535));
            }
            else if(command.substring(0, 2).equals("26")){
                register=r.nextInt(1+Integer.parseInt(command.substring(2,6),16));
            }
            else if(command.substring(0, 2).equals("30")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                Stack<Integer> stack2=stacks.get(Integer.parseInt(command.substring(4,6),16));
                int m=stack.pop(),n=stack.pop();
                stack2.push((m==n)?1:0);
            }else if(command.substring(0, 2).equals("31")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                Stack<Integer> stack2=stacks.get(Integer.parseInt(command.substring(4,6),16));
                int m=stack.pop(),n=stack.pop();
                stack2.push((m>n)?1:0);
            }else if(command.substring(0, 2).equals("32")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                Stack<Integer> stack2=stacks.get(Integer.parseInt(command.substring(4,6),16));
                int m,n;
                try{m=stack.pop();n=stack.pop();}catch(Exception e){throw new Exception("Empty stack exception on line "+(x+1));}
                stack2.push((m<n)?1:0);
            }else if(command.substring(0, 2).equals("33")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                Stack<Integer> stack2=stacks.get(Integer.parseInt(command.substring(4,6),16));
                int m=stack.pop(),n=stack.pop();
                stack2.push((m+n!=0)?1:0);
            }else if(command.substring(0, 2).equals("34")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                Stack<Integer> stack2=stacks.get(Integer.parseInt(command.substring(4,6),16));
                int m,n;
                try{m=stack.pop();n=stack.pop();}catch(Exception e){throw new Exception("Empty stack exception on line "+(x+1));}
                stack2.push((m*n!=0)?1:0);
            }else if(command.substring(0, 2).equals("35")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                Stack<Integer> stack2=stacks.get(Integer.parseInt(command.substring(4,6),16));
                int m,n;
                try{m=stack.pop();n=stack.pop();}catch(Exception e){throw new Exception("Empty stack exception on line "+(x+1));}
                stack2.push((m*n==0&&m+n!=0)?1:0);
            }else if(command.substring(0, 2).equals("36")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                stack.push((register==0)?1:0);
            }
            else if(command.substring(0, 2).equals("40")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                stack.push(register);
                register=0;
            }
            else if(command.substring(0, 2).equals("41")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                try{register=stack.pop();}catch(Exception e){throw new Exception("Empty stack exception on line "+(x+1));}
            }else if(command.substring(0, 2).equals("42")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                try{register=stack.peek();}catch(Exception e){throw new Exception("Empty stack exception on line "+(x+1));}
            }else if(command.substring(0, 2).equals("43")){
                Stack<Integer> stack=stacks.get(Integer.parseInt(command.substring(2,4),16));
                register=Math.min(stack.size(),65535);
            }
            else if(command.substring(0, 2).equals("00")){
            }
            else{
                String s=command.substring(0, 2);
                throw new IllegalArgumentException("Invalid syntax on line "+(x+1)+":"+s+" is not a legal command");
            }
        }}catch(Exception exc){
            System.out.println("An exception was thrown!");
            exc.printStackTrace(System.out);
            exc.printStackTrace(error);
            status=-1;
        }
        PrintStream statusout=new PrintStream("status.txt");
        statusout.print(status);
        System.out.print("Halting with status "+status);
    }
}