Solved

avoiding java.util.ConcurrentModificationException in for loops

Posted on 2006-06-13
3
2,746 Views
Last Modified: 2007-12-19
What is the best way to avoid java.util.ConcurrentModificationException in the for loop below:

import java.util.Collection;
import java.util.Iterator;
import java.util.TreeSet;

import junit.framework.TestCase;

public class Test extends TestCase {


 
   public void testLoop()
   {
      Collection currentCollection = new TreeSet();
      currentCollection.add("AAA");
      currentCollection.add("BBB");
      currentCollection.add("CCC");
     
      Collection updatedCollection = new TreeSet();
      updatedCollection.add("CCC");
      updatedCollection.add("DDD");
      updatedCollection.add("EEE");
     
      for (Iterator iter = currentCollection.iterator(); iter.hasNext();) {
         String element = (String) iter.next();
         if(!updatedCollection.contains(element))
         {
            currentCollection.remove(element);
         }
         
      }
      assertTrue(currentCollection.contains("DDD"));
      assertTrue(currentCollection.contains("EEE"));
      assertFalse(currentCollection.contains("CCC"));
     
   }
   
}
0
Comment
Question by:aturetsky
  • 2
3 Comments
 
LVL 86

Accepted Solution

by:
CEHJ earned 250 total points
ID: 16897118
Try changing

>>currentCollection.remove(element);

to

iter.remove();
0
 
LVL 1

Author Comment

by:aturetsky
ID: 16898009
great, thanks !
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 16898060
:-)
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Exception after setting jdbc session management 2 52
java.io.BufferedReader   readLine()  //returns the entire file ? 4 60
javap bin 2 29
servlet example issue 6 32
Java had always been an easily readable and understandable language.  Some relatively recent changes in the language seem to be changing this pretty fast, and anyone that had not seen any Java code for the last 5 years will possibly have issues unde…
Java functions are among the best things for programmers to work with as Java sites can be very easy to read and prepare. Java especially simplifies many processes in the coding industry as it helps integrate many forms of technology and different d…
Viewers learn about the “for” loop and how it works in Java. By comparing it to the while loop learned before, viewers can make the transition easily. You will learn about the formatting of the for loop as we write a program that prints even numbers…
This tutorial covers a practical example of lazy loading technique and early loading technique in a Singleton Design Pattern.

867 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

21 Experts available now in Live!

Get 1:1 Help Now