コード例 #1
0
 /**
  * PUBLIC: Use a ScrollableCursor as the result collection.
  *
  * @param policy the scrollable cursor policy allows for additional result set options. Example:
  *     <p>ScrollableCursorPolicy policy = new ScrollableCursorPolicy()
  *     <p>policy.setResultSetType(ScrollableCursorPolicy.TYPE_SCROLL_INSENSITIVE);
  *     <p>query.useScrollableCursor(policy);
  *     <p>
  */
 public void useScrollableCursor(ScrollableCursorPolicy policy) {
   policy.setQuery(this);
   setContainerPolicy(policy);
 }
  public void test() {

    ReadAllQuery query = new ReadAllQuery();
    ScrollableCursor cursor = null;

    try {
      query.setReferenceClass(Employee.class);
      if (TYPE_SCROLL_INSENSITIVE_isSupported && CONCUR_UPDATABLE_isSupported) {
        query.useScrollableCursor(2);
      } else {
        ScrollableCursorPolicy policy = new ScrollableCursorPolicy();
        if (!TYPE_SCROLL_INSENSITIVE_isSupported) {
          policy.setResultSetType(ScrollableCursorPolicy.TYPE_SCROLL_SENSITIVE);
        }
        if (!CONCUR_UPDATABLE_isSupported) {
          policy.setResultSetConcurrency(ScrollableCursorPolicy.CONCUR_READ_ONLY);
        }
        policy.setPageSize(2);
        query.useScrollableCursor(policy);
      }
      //
      if (configuration != null) {
        ExpressionBuilder builder = new ExpressionBuilder();
        Expression exp = builder.get("salary").greaterThan(50000);
        query.setSelectionCriteria(exp);
        query.conformResultsInUnitOfWork();
      }
      cursor = (ScrollableCursor) getSession().executeQuery(query);

      try {
        // test to see if we can iterate through a list and then iterate
        // in reverse through the same list.
        int totalItems = 0;
        while (cursor.hasNext()) {
          readWithNext.addElement(cursor.next());
          totalItems++;
        }
        while (cursor.hasPrevious()) {
          readWithPrevious.addElement(cursor.previous());
          totalItems--;
        }

        cursorSuccess = (totalItems == 0);

        int size = readWithPrevious.size();
        for (int i = 0; i < readWithNext.size(); i++) {
          cursorSuccess =
              (cursorSuccess
                  && (readWithNext.elementAt(i) == readWithPrevious.elementAt((size - 1) - i)));
        }

      } catch (org.eclipse.persistence.exceptions.QueryException ex) {
        caughtException = ex;
      }

    } finally {
      if (cursor != null) {
        cursor.close();
      }
    }
  }