java - 迭代键集时更新条目

Question

如何在迭代键的同时完成更新条目

Map<String,List<SObject>> Map1=new HashMap<String,List<SObject>>();
Map<String,List<SObject>> Map2=new HashMap<String,List<SObject>>();

for(String name: Map1.keyset()){
//do something

   for(SObject obj1: Map1.get(name)){
    //iterate through the list of SObjects returned for the key 

        for(SObject obj2 : Map2.get(name)){
        //iterate through the list of SObject values for the keys and update or remove the values related to the key
        }
   }
 }

Answer 1

您可以在 map 的entrySet上使用迭代器 - map.entrySet().iterator()

确保在迭代 map 时没有其他任何东西正在修改 map ，但只要您满足以下条件，您自己的修改就是安全的:

- only remove items using the iterator's remove() method, and
- only modify a value by using the Map.Entry setValue() method

参见http://docs.oracle.com/javase/6/docs/api/java/util/Map.html#entrySet()