java 中遍历取值异常（Hashtable Enumerator）解决办法

//使用迭代器遍历       Iterator<String> it = tableProper.stringPropertyNames().iterator();             sqlMap = new HashMap<String,String>();       while(it.hasNext()){         sqlMap.put(it.next(), tableProper.getProperty(it.next()));       } 

//使用迭代器遍历       Iterator<String> it = tableProper.stringPropertyNames().iterator();             sqlMap = new HashMap<String,String>();       String key;       while(it.hasNext()){         key = it.next();         sqlMap.put(key, tableProper.getProperty(key));       }