试试这个:

static String getKeyFromValue(LinkedHashMap<String, String> map,String value) {
    for (int x=0;x<map.size();x++){
        if( String.valueOf( (new ArrayList<String>(map.values())).get(x) ).equals(value))
            return String.valueOf((new ArrayList<String>(map.keySet())).get(x));
    }
    return null;
}

for(int key: hm.keySet()) {
    if(hm.get(key).equals(value)) {
        System.out.println(key); 
    }
}

Lambda w/o使用外部库 一个键可以处理多个值(与BidiMap不同)

public static List<String> getKeysByValue(Map<String, String> map, String value) {
  List<String> list = map.keySet().stream()
      .collect(groupingBy(k -> map.get(k))).get(value);
  return (list == null ? Collections.emptyList() : list);
}

获取一个包含键映射值的列表 对于1:1映射，返回的列表为空或包含1个值

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

public class M{
public static void main(String[] args) {

        HashMap<String, List<String>> resultHashMap = new HashMap<String, List<String>>();

        Set<String> newKeyList = resultHashMap.keySet();


        for (Iterator<String> iterator = originalHashMap.keySet().iterator(); iterator.hasNext();) {
            String hashKey = (String) iterator.next();

            if (!newKeyList.contains(originalHashMap.get(hashKey))) {
                List<String> loArrayList = new ArrayList<String>();
                loArrayList.add(hashKey);
                resultHashMap.put(originalHashMap.get(hashKey), loArrayList);
            } else {
                List<String> loArrayList = resultHashMap.get(originalHashMap
                        .get(hashKey));
                loArrayList.add(hashKey);
                resultHashMap.put(originalHashMap.get(hashKey), loArrayList);
            }
        }

        System.out.println("Original HashMap : " + originalHashMap);
        System.out.println("Result HashMap : " + resultHashMap);
    }
}

使用Java 8:

ftw.forEach((key, value) -> {
    if (value.equals("foo")) {
        System.out.print(key);
    }
});

使用薄包装:HMap

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

public class HMap<K, V> {

   private final Map<K, Map<K, V>> map;

   public HMap() {
      map = new HashMap<K, Map<K, V>>();
   }

   public HMap(final int initialCapacity) {
      map = new HashMap<K, Map<K, V>>(initialCapacity);
   }

   public boolean containsKey(final Object key) {
      return map.containsKey(key);
   }

   public V get(final Object key) {
      final Map<K, V> entry = map.get(key);
      if (entry != null)
         return entry.values().iterator().next();
      return null;
   }

   public K getKey(final Object key) {
      final Map<K, V> entry = map.get(key);
      if (entry != null)
         return entry.keySet().iterator().next();
      return null;
   }

   public V put(final K key, final V value) {
      final Map<K, V> entry = map
            .put(key, Collections.singletonMap(key, value));
      if (entry != null)
         return entry.values().iterator().next();
      return null;
   }
}