| /******************************************************************************* |
| * Copyright (c) 2011 Oracle. All rights reserved. |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v1.0, which accompanies this distribution |
| * and is available at http://www.eclipse.org/legal/epl-v10.html. |
| * |
| * Contributors: |
| * Oracle - initial API and implementation |
| ******************************************************************************/ |
| package org.eclipse.jpt.common.utility.internal; |
| |
| import java.io.Serializable; |
| |
| import org.eclipse.jpt.common.utility.Filter; |
| |
| /** |
| * This filter accepts only non-<code>null</code>, non-empty, |
| * non-whitespace-only strings. |
| */ |
| public class NonEmptyStringFilter |
| implements Filter<String>, Serializable |
| { |
| public static final Filter<String> INSTANCE = new NonEmptyStringFilter(); |
| |
| public static Filter<String> instance() { |
| return INSTANCE; |
| } |
| |
| // ensure single instance |
| private NonEmptyStringFilter() { |
| super(); |
| } |
| |
| // accept only non-null objects |
| public boolean accept(String string) { |
| return StringTools.stringIsNotEmpty(string); |
| } |
| |
| @Override |
| public String toString() { |
| return this.getClass().getSimpleName(); |
| } |
| |
| private static final long serialVersionUID = 1L; |
| private Object readResolve() { |
| // replace this object with the singleton |
| return INSTANCE; |
| } |
| } |