001    /*
002     * Copyright (C) 2012 eXo Platform SAS.
003     *
004     * This is free software; you can redistribute it and/or modify it
005     * under the terms of the GNU Lesser General Public License as
006     * published by the Free Software Foundation; either version 2.1 of
007     * the License, or (at your option) any later version.
008     *
009     * This software is distributed in the hope that it will be useful,
010     * but WITHOUT ANY WARRANTY; without even the implied warranty of
011     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012     * Lesser General Public License for more details.
013     *
014     * You should have received a copy of the GNU Lesser General Public
015     * License along with this software; if not, write to the Free
016     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018     */
019    
020    package org.crsh.util;
021    
022    import java.util.ArrayList;
023    import java.util.HashMap;
024    import java.util.HashSet;
025    import java.util.Iterator;
026    import java.util.LinkedList;
027    import java.util.List;
028    
029    public class Utils {
030    
031      public static <E> ArrayList<E> newArrayList() {
032        return new ArrayList<E>();
033      }
034    
035      public static <E> LinkedList<E> newLinkedList() {
036        return new LinkedList<E>();
037      }
038    
039      public static <E> HashSet<E> newHashSet() {
040        return new HashSet<E>();
041      }
042    
043      public static <K, V> HashMap<K, V> newHashMap() {
044        return new HashMap<K, V>();
045      }
046    
047      public static <E>List<E> list(Iterable<E> iterable) {
048        return list(iterable.iterator());
049      }
050    
051      public static <E>List<E> list(Iterator<E> iterator) {
052        ArrayList<E> list = new ArrayList<E>();
053        while (iterator.hasNext()) {
054          list.add(iterator.next());
055        }
056        return list;
057      }
058    
059      public static int indexOf(CharSequence s, int off, char c) {
060        for (int len = s.length();off < len;off++) {
061          if (s.charAt(off) == c) {
062            return off;
063          }
064        }
065        return -1;
066      }
067    
068      public static String trimLeft(String s) {
069        if (s == null) {
070          throw new NullPointerException("No null string accepted");
071        }
072        int index = 0;
073        int len = s.length();
074        while (index < len) {
075          if (s.charAt(index) == ' ') {
076            index++;
077          } else {
078            break;
079          }
080        }
081        if (index > 0) {
082          return s.substring(index);
083        } else {
084          return s;
085        }
086      }
087    
088      public static <E> E notNull(E e1, E e2) {
089        if (e1 != null) {
090          return e1;
091        } else {
092          return e2;
093        }
094      }
095    }