Trie datastructure simple implementation of insert and delete in java

Trie.java

//import java.util.*;
public class Trie {
	private static final int ALPHABET_SIZE = 26;
	private TrieNode root;
	private int count;
	public Trie() {
		this.root = new TrieNode();
		this.count = 0;
	}
	public void insert(String key) {
		this.count++;
		TrieNode cur = this.root;
		for (int i = 0; i < key.length(); i++) {
			int idx = (int) key.charAt(i) - (int) 'a';
			if(cur.children[idx] == null) {
				cur.children[idx] = new TrieNode();
			}
			cur = cur.children[idx]; 
		}
		cur.value = this.count;
	}
	public boolean search(String key) {
		TrieNode cur = this.root;
		for (int i = 0; i < key.length(); i++) {
			int idx = (int) key.charAt(i) - (int) 'a';
			if(cur.children[idx] == null) {
				return false;
			}
			cur = cur.children[idx]; 
		}
		if(cur.value != 0 && cur != null)
			return true;
		return false;
	}
	private static class TrieNode {
		int value;
		TrieNode[] children;
		public TrieNode() {
			this.value = 0;
			this.children = new TrieNode[ALPHABET_SIZE];
			for(int i = 0; i < ALPHABET_SIZE; i++) 
				this.children[i] = null;
		} 
	}
}
// class Test {
// 	public static void main(String[] args) {
// 		Trie trie = new Trie();
// 		trie.insert("hello");
// 		trie.insert("hi");
// 		trie.insert("newyork");
// 		System.out.println(trie.search("hello") + " " +
// 		 trie.search("hi") + " "+  trie.search("newyork"));

// 	}
// }