如何初始化Hashtable

Question

如何初始化以下哈希表？

public static Hashtable<String, Hashtable<String, String>> tab = new Hashtable<String, Hashtable<String, String>>();    
static {
    tab.put("Key1", ????);
    tab.put("Key2", ????);
    tab.put("Key3", ????);
}

Answer 1

public static Hashtable<String, Hashtable<String, String>> tab = new Hashtable<String, Hashtable<String, String>>();    
static {
    tab.put("Key1", new HashTable<String,String>());
    ...
}

Answer 2

您可以使用例如空Hashtable s：

public static Hashtable<String, Hashtable<String, String>> tab = 
    new Hashtable<String, Hashtable<String, String>>();    
static {
    tab.put("Key1", new Hashtable<String, String>());
    tab.put("Key2", new Hashtable<String, String>());
    tab.put("Key3", new Hashtable<String, String>());
}

Answer 3

static {
    Hashtable<String, String> ob = new Hashtable<String, String>;
    ob.put("a","a");
     .. Put key/value...
    tab.put("Key1",ob);  
}