如何将一个hashmap内容复制到另一个hashmap

Question

这里我有两个哈希图dataz和screen_dataz.我想复制screen_dataz到dataz.

我这样想,但它不起作用:

Object[]  obj = new Object[5];
String[] strArray = new String[]{"Obj1","Array1","Converted1","To1","List1"};
String[] strArray1 = new String[]{"Obj2","Array2","Converted2","To2","List2"};
dataz.put(0,(Object[]) strArray);
dataz.put(1,(Object[]) strArray1);
// String dataString = (String) dataz;
System.out.println(dataz);


Object[]  obj1= new Object[5];
String[] strArray2 = new String[]{"Obj3","Array3","Converted3","To3","List3"};
String[] strArray3 = new String[]{"Obj4","Array4","Converted4","To4","List4"};
screen_dataz.put(0,(Object[]) strArray2);
screen_dataz.put(1,(Object[]) strArray3);
System.out.println("copying screen dataz to dataz");
dataz.putAll(screen_dataz);

Answer 1

利用构造函数和Shallow它.

dataz = new HashMap<Key,val>(screen_dataz);

Answer 2

你可以简单地构建一个新的:

dataz = new HashMap<Integer,Object>(screen_dataz);

Answer 3

Map tmp = new HashMap(patch);
tmp.keySet().removeAll(target.keySet());
target.putAll(tmp);

详细解释