克隆一个Properties对象

Question

我是一名Java初学者,所以请尽可能地提出愚蠢的问题.

我想构建一个Properties对象,然后克隆它.我需要克隆也是一个Properties对象,因为我需要对它应用适用于Properties对象的方法.

我写了以下代码:

公共类TryTask_B2 {

public static void main(String args[]) {

    Properties garList = new Properties();  // create "Properties" obj for 'Gar'
    Set gars;  // def a set for the 'Gar' keys
    String strGar;

    // Fill the "Properties" obj for 'Gar':
    garList.put("Gar_1", "rotura de lunas");
    garList.put("Gar_2", "arbitraje de ley");
    garList.put("Gar_3", "Adaptación del hogar");
    garList.put("Gar_4", "rotura de lunas");

    // Create clone of original "Properties" obj 'Gar':
    Object garList_clone = garList.clone();
    Set gars_clone;  // def a set for the cloned 'Gar' keys
    String strGar_clone;

    gars = garList.keySet();  // get a set-view of the 'Gar' keys
    Iterator itrGar = gars.iterator();
    gars_clone = garList_clone.keySet();  // get a set-view of the cloned 'Gar' keys
    Iterator itr_clone = gars_clone.iterator();

    Iterator itrGar_1 = gars.iterator();
    System.out.println("Original list of Gars: ");
    while(itrGar_1.hasNext()){
        strGar = (String) itrGar_1.next();  
        System.out.println(strGar + " : " + garList.getProperty(strGar) + ".");  
    }
    System.out.println();

    // Compare string-value entries for each and every key in the two lists:
    while(itrGar.hasNext()){
        strGar = (String) itrGar.next();  
        while(itr_clone.hasNext()){
            String str1 = garList.getProperty(strGar);
            strGar_clone = (String) itr_clone.next();  
            String str2 = garList_clone.getProperty(strGar_clone);
            boolean result = str1.equalsIgnoreCase(str2);
            System.out.println(strGar + " : " + str1 + ".");
            System.out.println(strGar_clone + " : " + str2 + ".");
            System.out.println(result);
            System.out.println();
            if(result != true){
            } else {
                Object garList_new = garList.remove(strGar);
                System.out.println("Removed element: " + garList_new);
                System.out.println();
            }
        }
        itr_clone = gars_clone.iterator();
    }

    Iterator itrGar_2 = gars.iterator();
    System.out.println("New list of Gars: ");
    while(itrGar_2.hasNext()){
        strGar = (String) itrGar_2.next();              
        System.out.println(strGar + " : " + garList.getProperty(strGar) + ".");  
    }
    System.out.println();
}

}

但它给我一个错误,将方法"keySet()"和"getProperty()"应用到我的克隆...为什么？

Answer 1

因为Object garList_clone = garList.clone();是 anObject而不是 a Properties。

改变它，

 Object garList_clone = garList.clone();

到

 Properties garList_clone = (Properties) garList.clone();