public class CustomValidator extends ResourceValidatorImpl
{
  private List<Issue> issues;

  @Override
  public List<Issue> validate(final Resource resource, final CheckMode mode, final CancelIndicator monitor)
    throws OperationCanceledError
  {
    return  super.validate(resource, mode, new CustomCancelIndicator(monitor));
  }

  @Override
  protected IAcceptor<Issue> createAcceptor(final List<Issue> result)
  {
    this.issues = result;
    return super.createAcceptor(issues);
  }

  private class CustomCancelIndicator implements CancelIndicator
  {
    private static final int MAX_CHECKED_ERRORS = 1000;
    private final CancelIndicator monitor;

    public CustomCancelIndicator(final CancelIndicator monitor)
    {
      this.monitor = monitor;
    }

    @Override
    public boolean isCanceled()
    {
      if (monitor.isCanceled())
      {
        return true;
      }

      return issues == null
        ? false
        : issues.size() > MAX_CHECKED_ERRORS;
    }
  }
}