我有一个最终的非静态成员:
private final HashMap<String,String> myMap;
我想使用构造函数调用的方法对其进行初始化。由于 myMap 是最终的,我的“帮助”方法无法直接初始化它。当然我有选择:
我可以直接在构造函数中实现 myMap 初始化代码。
MyConstructor (String someThingNecessary)
{
myMap = new HashMap<String,String>();
myMap.put("blah","blahblah");
// etc...
// other initialization stuff unrelated to myMap
}
我可以让我的辅助方法构建 HashMap,将其返回给构造函数,然后让构造函数将对象分配给 myMap。
MyConstructor (String someThingNecessary)
{
myMap = InitializeMyMap(someThingNecessary);
// other initialization stuff unrelated to myMap
}
private HashMap<String,String> InitializeMyMap(String someThingNecessary)
{
HashMap<String,String> initializedMap = new HashMap<String,String>();
initializedMap.put("blah","blahblah");
// etc...
return initializedMap;
}
方法 #2 很好,但是,我想知道是否有某种方法可以让辅助方法直接操作 myMap。也许一个修饰符表明它只能由构造函数调用?
MyConstructor (String someThingNecessary)
{
InitializeMyMap(someThingNecessary);
// other initialization stuff unrelated to myMap
}
// helper doesn't work since it can't modify a final member
private void InitializeMyMap(String someThingNecessary)
{
myMap = new HashMap<String,String>();
myMap.put("blah","blahblah");
// etc...
}