java中的多值映射
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MultiValueMap in java
提问by user3810857
I'm studying with Hashmap with Multiple parameters(1 key, 2 values) and i was able to find apache multiValueMap for my issue.
我正在研究具有多个参数（1 个键，2 个值）的 Hashmap，我能够找到 apache multiValueMap 来解决我的问题。
Here is my codes for multiValueMap.
这是我的 multiValueMap 代码。
import java.util.Set;
import org.apache.commons.collections.map.MultiValueMap;
import org.apache.commons.collections.MultiMap;
public class multiValueMap {
public static void main(String args[]) {
String a, b, c;
MultiMap mMap = new MultiValueMap();
mMap.put("a", "Hello there, It's a wonderful day");
mMap.put("a", "nice to meet you");
Set<String> keys = mMap.keySet();
for (String key : keys) {
System.out.println("Key = " + key);
System.out.println("Values = " + mMap.get(key));
a = String.valueOf(mMap.get(key));
System.out.println("A : " + a);
}
}
}
// The result as below
Key = a
Value = [Hello there, It's a wonderful day, nice to meet you]
A : [Hello there, It's a wonderful day, nice to meet you]
Here is my question how can I store first value for string b, and second for c?if I substring the MultiMap values depends on "," then it would stores Hello there only. please give me helpful your advices.
这是我的问题， 如何为字符串 b 存储第一个值，为 c 存储第二个值？如果我将 MultiMap 值子字符串取决于“，”，那么它只会在那里存储 Hello。请给我有用的建议。
采纳答案by Sach141
You can try following :
您可以尝试以下操作：
String a, b, c;
MultiMap mMap = new MultiValueMap();
mMap.put("a", "Hello there, It's a wonderful day");
mMap.put("a", "nice to meet you");
Set<String> keys = mMap.keySet();
for (String key : keys) {
System.out.println("Key = " + key);
System.out.println("Values = " + mMap.get(key));
List<String> list = (List<String>) mMap.get(key);
b = list.get(0);
c = list.get(1);
System.out.println("B : " + b);
System.out.println("C : " + c);
}
回答by Praba
You don't have to do a split. This is the documentation of MultiMap that is found:
您不必进行拆分。这是找到的 MultiMap 的文档：
MultiMap mhm = new MultiHashMap();
mhm.put(key, "A");
mhm.put(key, "B");
mhm.put(key, "C");
Collection coll = (Collection) mhm.get(key);
Now when you do a get()call on a multimap, it gives you a collection. The first item will be your b and the second one will be your c.
现在，当您在多地图上进行get()调用时，它会为您提供一个集合。第一项将是您的 b，第二项将是您的 c。
回答by Ronit
You can also use a key and object to store multiple values in Multimap. Something like this, MultiValueMap mv = new LinkedMultiValueMap<~>();
您还可以使用键和对象在 Multimap 中存储多个值。像这样， MultiValueMap mv = new LinkedMultiValueMap<~>();
