11章-练习24

import java.util.*;

/**
 * 练习24：使用String键和你选择的对象填充LinkedHashMap.然后从中提取键值对，以键排序，然后重新插入此Map
 */
public class Exercise24 {

    public static void main(String[] args) {

        Map<String, Integer> linkedHashMap = new LinkedHashMap<String, Integer>();
        linkedHashMap.put("a", 1);
        linkedHashMap.put("e", 2);
        linkedHashMap.put("i", 3);
        linkedHashMap.put("b", 4);
        linkedHashMap.put("c", 5);
        System.out.println("to sort map : " + linkedHashMap);
        List<String> list = new ArrayList<>();
        list.addAll(linkedHashMap.keySet());
        Collections.sort(list);
        for (String key : list) {
            int value = linkedHashMap.get(key);
            linkedHashMap.remove(key);
            linkedHashMap.put(key, value);
        }
        System.out.println("sorted map : " + linkedHashMap);
    }
}
/*
to sort map : {a=1, e=2, i=3, b=4, c=5}
sorted map : {a=1, b=4, c=5, e=2, i=3}
 *///:~