Buffer.position throws IllegalArgumentException

Question

Hi i tried the following code on linux using jdk1.4.2_05. on windows the
same code same jdk and successfully done. Only linux throws me a illegalArgumentException.
Anyone experience the same as i do.
import java.io.*;
import java.nio.*;
import java.nio.channels.*;
import java.text.*;
import java.util.*;
public class Process{
     private static MappedByteBuffer mbb;
     private static LinkedList table;
     private static FileChannel fc;
     private String gl_record;
     private String gl_pathname;
     public Process(String pathname){
          gl_pathname = pathname;
          if(table == null){
               gl_record = "";
               if(initTable() != 0)
                    return ;
     public long enqueue(String record) {
          record = " " + record;
          if(!record.endsWith("\n"))
               record += "\n";
          try{
               ByteBuffer bb = ByteBuffer.wrap(record.getBytes());
               long pos = -1;
               RandomAccessFile raf = new RandomAccessFile(gl_pathname, "rws");
               FileChannel fc = raf.getChannel();
               pos = fc.size();
               fc.write(bb, pos);
               table.add(new Long(pos));
               createBuffer(gl_pathname);
               fc.close();
               return pos;
          }catch(IOException e){
               e.printStackTrace();
               return -1;
     public long dequeue(String record){
          if(table.size() > 0){
               Long obj = (Long)table.removeFirst();
               int pos = obj.intValue();
               try{                                      //<---------------------Error Occurs Here
                    mbb.position(pos);
               }catch(IllegalArgumentException e){
                    e.printStackTrace();
                    return -100;
               char c;
               String s = "";
               while(mbb.hasRemaining()){
                    c = (char)mbb.get();
                    s += c;
                    if(c == '\n'){
                         if(s.startsWith(" ")){
                              gl_record = s;
                              return pos;
                    s = "";
          return -1;
     public int comment_record(long record_pos) {
               ByteBuffer bb = ByteBuffer.wrap("#".getBytes());
               int position = mbb.position();
               mbb.position((int)record_pos);
               mbb.put(bb);
               mbb.force();
               mbb.position(position);
          return 0;
     private int initTable(){
          int result = createBuffer(gl_pathname);
          if(result != 0){
               return -1;
          table = new LinkedList();
          String line = "";
          while(mbb.hasRemaining()){
               char c = (char)mbb.get();
               line += c;
               if(c == '\n'){
                    char readAvailable = line.charAt(0);
                    if(" ".equals(String.valueOf(readAvailable))){
                         table.add(new Long(mbb.position() - line.length()));
                    line = "";
          return 0;
     private int createBuffer(String pathname){
          try{
               RandomAccessFile raf = new RandomAccessFile(pathname, "rws");
               FileChannel fc = raf.getChannel();
               mbb = fc.map(FileChannel.MapMode.READ_WRITE, 0, fc.size());
               fc.close();
          }catch(IOException e){
               return -1;
          return 0;
      public static void main(String[] args){
          Process proc = new Process("testing");
          for(int i = 0; i < 10000; i++){
               long res = proc.dequeue("");
               proc.enqueue("AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA                   aaaaaaaaa");
               if(res >= 0){
                    proc.comment_record(res);
               }else if(res < -1)
                    break;
}

Answer 1

The
[url=http://java.sun.com/javase/6/docs/api/java/nio/Bu
ffer.html#position(int)]position method takesan int, but you're feeding it a long.
It's an int but may be negative?
OP's code:
Long obj = (Long)table.removeFirst();
               int pos = obj.intValue();
               try{                                      //<---------------------Error Occurs Here
                    mbb.position(pos);