复制代码 代码如下:

import java.util.ArrayList;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;

import java.util.Set;

public class MapValueGetKey {

public static void main(String[] args) {

Map map = new HashMap<>();

map.put(1,"A");

map.put(2,"A");

map.put(3,"A");

map.put(4,"A");

map.put(5,"A");

String value = "A";

ArrayList arr = valueGetKey(map, value);

if(!arr.isEmpty()) {

for(int i=0; i<arr.size(); i++) {

System.out.println(arr.get(i));

}

}

}

private static ArrayList valueGetKey(Map map,String value) {

Set set = map.entrySet();

ArrayList arr = new ArrayList<>();

Iterator it = set.iterator();

while(it.hasNext()) {

Map.Entry entry = (Map.Entry)it.next();

if(entry.getValue().equals(value)) {

int s = (int)entry.getKey();

arr.add(s);

}

}

return arr;

}

}

结果如下：

复制代码 代码如下:

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5