去掉map中 value 为空的数据

       /**
* 方式一：运算次数较多
* @param paramMap
* @return
*/
public static Map<String,String> removeMapEmptyValue1(Map<String,String> paramMap){
Set<String> set = paramMap.keySet();
Iterator<String> it = set.iterator();
while (it.hasNext()) {
  String str = it.next();
  if(paramMap.get(str)==null || paramMap.get(str) ==""){
  paramMap.remove(str);
  set = paramMap.keySet();
  it = set.iterator();
  }
}
       
return paramMap;
}

/**
* 方式二：
* @param paramMap
* @return
*/
public static Map<String,String> removeMapEmptyValue(Map<String,String> paramMap){
Set<String> set = paramMap.keySet();
Iterator<String> it = set.iterator();
List<String> listKey = new ArrayList<String>();
while (it.hasNext()) {
  String str = it.next();
  if(paramMap.get(str)==null || "".equals(paramMap.get(str))){
listKey.add(str) ;
  }
}
       for (String key : listKey) {
       paramMap.remove(key);
   }
return paramMap;

}