map根据key进行排序

【java】Comparator的用法 ：具体参考/u012250875/article/details/55126531/

这两种其实都差不多，只是匿名内部类的不同写法而已。项目环境jdk7，故没用labmda表达式。

第一种： 

public Map<String, Object> getDataQx(List<ReportTableEntity> listTime,List<TSType> listsig) {
		Map<String, Object> map = new HashMap<String, Object>();// 查询条件
		Map<String, Object> dateMap = new HashMap<String, Object>();
		Map<String, Object> dateRootMap = null;
		Map<String, Object> mapinfo = null;
		Map<String, Object> resultMap =null ;
		List<SiteInfoSnapshotEntity> sEntities = new ArrayList<>();
		for (ReportTableEntity reportTableEntity : listTime) {
			dateRootMap = new HashMap<String, Object>();// 放数据
			for (TSType typeEntity : listsig) {
				("county", ());
				("dtime", ());
				sEntities = (map);
				// 区县对应的数据
				mapinfo = new HashMap<String, Object>();// 放每个区县的详情
				("info", (0));
				((), mapinfo);

			}
			// 日期> 区县 > 数据
			((), dateRootMap);
			// ----------------------------
			 resultMap = sortMapByKey(dateMap);  //按Key进行排序

		        for (<String, Object> entry : ()) {
		            (() + " " + ());
		        }
			// ----------------------------
		}
		return resultMap;
	}

public static Map<String, Object> sortMapByKey(Map<String, Object> map) {
		if (map == null || ()) {
			return null;
		}
        //利用匿名内部类，重写compare to 方法
		
		Map<String, Object> sortMap = new TreeMap<String, Object>(new MapKeyComparator());

		(map);

		return sortMap;
	}

public class MapKeyComparator implements Comparator<String> {
	

	    @Override
	    public int compare(String str1, String str2) {

	        return (str1);
	    }
	}

 

第二种：

public static Map<String, Object> sortMapByKey(Map<String, Object> map) {
		if (map == null || ()) {
			return null;
		}
		
		Map<String, Object> sortMap = new TreeMap<String, Object>(new Comparator<String>() {

			@Override
			public int compare(String o1,String o2) {
				
				return ((String)o1).compareTo((String) o2);
			}
		});

		(map);

		return sortMap;
	}