java根据map指定的value值获取对应的key值使用Gson实现

public  void  checkmap(){
try {
Map<String,String> map = new HashMap();
map.put("a","1");
map.put("b","study");
map.put("c","3");
map.put("d","4");
Set keysets = map.keySet();
String ketStr=new Gson().toJson(keysets);
List<String> keyLists =   new Gson().fromJson(ketStr,new TypeToken<List<String>>(){}.getType());
List<String> valuesSet = new ArrayList<String>(map.values());
String svalue = "study";
int keyIndex = valuesSet.indexOf(svalue);
System.out.println(keyLists.get(keyIndex) + "-------"+svalue);

} catch (Exception e) {
e.printStackTrace();