Java Programming

I hope you will all forgive me because this has been exhausted although I followed all the advices.

After the following examples, to check my own environment. I have done the following:

 long heapSize = Runtime.getRuntime().totalMemory();
    System.out.println(heapSize);
    // Get maximum size of heap in bytes. The heap cannot grow beyond this size.
    // Any attempt will result in an OutOfMemoryException.
    long heapMaxSize = Runtime.getRuntime().maxMemory();
    System.out.println(heapMaxSize);
    // Get amount of free memory within the heap in bytes. This size will increase
    // after garbage collection and decrease as new objects are created.
    long heapFreeSize = Runtime.getRuntime().freeMemory();
    System.out.println(heapFreeSize);
	   

Which outputs is:
5177344
66650112
4437824

Currently, it looks like my heap cannot grow more than 6.6M right?

Now if I want to increase my maximum heap size, the command is adviced to be:
java -Xmx128m readFile.class


However, it keeps coming oout with an error:
Exception in thread "main" java.lang.NoClassDefFoundError: readFile/class

Where did that "main" come from? The only thing that I have done is that I have another class called myMain which calls this clss for test purposes.

The class which raised this heap problem was a class I was using to read files as in the bellow:

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

public class readFile
{
private ArrayList<String>  dataFromFile= new ArrayList<String>();
   ....
    public String readFile(String fileNameIn, String encoding) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(
      new FileInputStream(fileNameIn), encoding));
      buffer = new StringBuffer();
    int i;
    while((i = in.read()) != -1) buffer.append((char)i);
    in.close();
    return buffer.toString();
  }

//return an array of each data read from file separated by a tab etc
  public ArrayList<String> getRecords(String fileNameIn) throws IOException {
      String  s = this.readFile(fileNameIn);
      String current;
  
      Pattern p = Pattern.compile("[^\t\n]+|\t(?=\t)|\t$", 
      Pattern.CASE_INSENSITIVE);
      Matcher m = p.matcher(s);
      
      while(m.find()){
         current = m.group(0).trim();
         dataFromFile.add(current);
        }//while  
    return dataFromFile;
    }
  ....
  
}

Message was edited by:
McTaar

Message was edited by:
McTaar