Map的List集合排序

Map的List集合排序

package abcdefg;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Com {
	/**
	 * @param args
	 */
	@SuppressWarnings({ "rawtypes", "unchecked" })
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
		Map<String, Object> map1 = new HashMap<String, Object>();
		map1.put("ss_id", "1");
		map1.put("distance", "0.7245");
		Map<String, Object> map2 = new HashMap<String, Object>();
		map2.put("ss_id", "2");
		map2.put("distance", "4.3839");
		Map<String, Object> map3 = new HashMap<String, Object>();
		map3.put("ss_id", "3");
		map3.put("distance", "1.449");
		list.add(map1);
		list.add(map2);
		list.add(map3);
		// 排序前
		for (Map<String, Object> map : list) {
			System.out.println(map.get("distance"));
		}
		Collections.sort(list, new Comparator<Map<String, Object>>() {
			public int compare(Map<String, Object> o1, Map<String, Object> o2) {
				String name1 = (String) o1.get("distance");
				String name2 = (String) o2.get("distance"); 
				return name1.compareTo(name2);
			}
		});
		// 排序后
		System.out.println("-------------------");
		for (Map<String, Object> map : list) {
			System.out.println(map.get("distance"));
		}
	}
}