package com.yuji.tdb.db;

import javax.jdo.PersistenceManager;

public class KeyValueDao {
	private static KeyValueDao instance = null;
	
	public static KeyValueDao getInstance(){
		if (instance == null){
			instance = new KeyValueDao();
		}
		return instance;
	}
	
	private PersistenceManager pm = PMFactory.get().getPersistenceManager();
	
	public String get(String key){
		KeyValue keyValue = pm.getObjectById(KeyValue.class, key);
		if (keyValue == null){
			return null;
		}
		return keyValue.getValue();
	}
	
	public void put(String key, String value){
		KeyValue keyValue = new KeyValue(key, value);
		pm.makePersistent(keyValue);
	}
}