Thread: Null Pointer Excpetion help......

Help needed .. Null pointer Exception..

 
[B][I][U]//Execution class .......
[/U][/I][/B]
 
public class Execution {
 
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		WordList wordList = new WordList();
		Word word1 = new Word("abd"); 
		Word word2 = new Word("abdede");
		Word word3 = new Word("abddwd");                   // TODO Auto-generated method stub
		wordList.addWord(word1);				//NUll Point Exception here.. Can some one explains why???
		wordList.addWord(word2);
		wordList.addWord(word3);
		wordList.displayWordsOfLength(2);
 
	}
 
}
 
 
 
 
[B][I][U]//////WordList Class[/U][/I][/B]
 
 
import java.util.ArrayList;
 
public class WordList {
 
						ArrayList<Word> wordList;
 
 
						public WordList() {
							super();
 
						}
 
						public ArrayList<Word> getWordList() {
							return wordList;
						}
 
						public void setWordList(ArrayList<Word> wordList) {
							this.wordList = wordList;
						}
					public void addWord(Word word)                                 // NULL POINTER EXCEPTION PLEASE EXPLAIN WHY?
					{
						wordList.add(word);
					}
					public void displayWordsOfLength(int length)
					{
						for(Word word :wordList)
						{
							if(word.getWord().length()== length)
								System.out.println("Word with length: "+length+"    "+word.getWord());
					}
					}
						public void removeWord(String inputWord){
							for(Word word :wordList)
							{
								if(word.getWord().equalsIgnoreCase(inputWord))
								{
									wordList.remove(word);
									System.out.println("Word  "+inputWord+"  is removed  "+word.getWord());
 
						}
							}
 
[I][U][B]//WORD CLASS[/B][/U][/I]
 
 
 
 
public class Word {
 
			private String word ;
			private int length ;
 
			public Word(String word) {
				super();
				this.word = word;
			}
 
			public String getWord() {
				return word;
			}
			public void setWord(String word) {
				this.word = word;
			}
 
 
}

Thanks !!!! i got it... i hadn't created the object of the ArrayList in the WordList class......

public void addWord(Word word)
					{
						wordList = new ArrayList<Word>();      //this was missing in WordList.java
						wordList.add(word);
					}