如何从hashmap值获取对象数组的数组？

Question

请原谅没有详细说明问题。我确信下面的例子会告诉你我的意思。我需要从hashmap中获取anObject的所有值。正如你可以从下面的例子看到的，关键是anObject，并且该值将是一个anObject数组。

HashMap<anObject,anObject[]> testMap = new HashMap<anObject,anObject[]>(); //Define map 

anObject someObject1 = new anObject("one"); 
anObject someObject2 = new anObject("two") 

anObject[] manyObjects1 = new anObject[3]; 
manyObjects1[0] = new anObject(0); 
manyObjects1[1] = new anObject(1); 
manyObjects1[2] = new anObject(2); 
anObject[] manyObjects2 = new anObject[3]; 
manyObjects2[0] = new anObject(0); 
manyObjects2[1] = new anObject(1); 
manyObjects2[2] = new anObject(2); 

testMap.put(someObject1,manyObjects1); 
testMap.put(someObject2,manyObjects2); 

//Get anObject from all the values put into testMap 
anObject[] getAllValues1 = (anObject[])testMap.values().toArray; //is this correct or 
anObject[][] getAllValues2 = (anObject[][])testMap.values().toArray; //is this correct 

Answer 1

你想使用toArray(T[])：

Collection values = testMap.values(); 
anObject[][] getAllValues2 = (anObject[][])values.toArray(new anObject[values.size()][]); 

因为你找回在地图中值的数组，并在地图中的值是数组，你需要指出你回来的是一组数组，所以[][]。