java中遍历取值异常（HashtableEnumerator）解决办法

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

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