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
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