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：
1
2
3
4
5
更多java hashmap通过value反查key的代码示例。
