Java中List

第一種方法，就是list中對象實現Comparable接口，代碼如下：

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 Test {
    public static void main(String[] args) {
         
        List<Map<String, String>> data = new ArrayList<Map<String, String>>();
 
        init(data);
 
        System.out.println("排序前:");
        System.out.println(data);
        sort(data);
        System.out.println("排序後:");
        System.out.println(data);
    }
 
    private static void sort(List<Map<String, String>> data) {
 
        Collections.sort(data, new Comparator<Map>() {
 
            public int compare(Map o1, Map o2) {
 
                String a = (String) o1.get("PRECOUNTOUT");
                String b = (String) o2.get("PRECOUNTOUT");
 
                // 升序
                return a.compareTo(b);
 
                // 降序
                // return b.compareTo(a);
            }
        });
    }
 
    private static void init(List<Map<String, String>> data) {
 
        Map<String, String> map = new HashMap<String, String>();
        map.put("COUNTTICKET", "a");
        map.put("PRECOUNTOUT", "abd");
        data.add(map);
 
        map = new HashMap<String, String>();
        map.put("COUNTTICKET", "b");
        map.put("PRECOUNTOUT", "abc");
        data.add(map);
 
        map = new HashMap<String, String>();
        map.put("COUNTTICKET", "c");
        map.put("PRECOUNTOUT", "d");
        data.add(map);
 
        map = new HashMap<String, String>();
        map.put("COUNTTICKET", "d");
        map.put("PRECOUNTOUT", "a");
        data.add(map);
    }
}