Page History

public class ShowHeapError {
  Vector<String>Vector&lt;String&gt; names = new Vector<String>Vector&lt;String&gt;();
  InputStreamReader input = new InputStreamReader(System.in);
  BufferedReader reader = new BufferedReader(input);

  public void addNames() throws IOException {
    while(true) {     
      // Adding unknown number of records to a list; user can exhaust the heap
      String newName = reader.readLine();
      if(!newName.equalsIgnoreCase("quit"&quot;quit&quot;)) { // Enter "quit"&quot;quit&quot; to quit the program
        names.addElement(newName);
      } else {
    	break;
      }
    }
    // Close "reader"&quot;reader&quot; and "input"&quot;input&quot;
  }

  public static void main(String[] args) throws IOException {
    ShowHeapError demo = new ShowHeapError();
    demo.addNames();
  }
}

/** Assuming the heap size as 512 MB (calculated as 1/4th of 2 GB RAM = 512 MB)
 *  Considering long values being entered (64 bits each, the max number of elements
 *  would be 512 MB/64bits = 67108864)
 */
public class ShowHeapError {
   Vector<Long>Vector&lt;Long&gt; names = new Vector<Long>Vector&lt;Long&gt;(); // Accepts unknown number of records
   long newID = 0L;
   int count = 67108865;
   int i = 0;
   InputStreamReader input = new InputStreamReader(System.in);
   Scanner reader = new Scanner(input);

   public void addNames(){
     do{
       // Adding unknown number of records to a list
       // The user can enter more number of IDs than what the heap can support and 
       // exhaust the heap. Assume that the record ID is a 64 bit long value
      
       System.out.print("&quot;Enter recordID (To quit, enter -1): "&quot;);
       newID = reader.nextLong();
       
       names.addElement(newID);
       i++;
     }while (i <&lt; count || newID != -1);
     // Close "reader"&quot;reader&quot; and "input"&quot;input&quot;
   }

   public static void main(String[] args) {
     ShowHeapError demo = new ShowHeapError();
     demo.addNames();
   }
}

FileOutputStream fos = new FileOutputStream(""data.txt"");
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(new Date());
// ... 

FileOutputStream fos = new FileOutputStream(""data.txt"");
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(new Date());
oos.reset();  // Reset the Object-Handle table to its initial state
// ...