关于Java的map存取数据的问题

Question

Answer 1

没有说清楚，但是感觉你的意思应该是这样的
public static void main(String[] args) throws Exception {
Map map1 = new HashMap();
map1.put("类型", "大");
map1.put("数量", "多");
map1.put("单价", 100);
map1.put("优惠", 0.12);

    Map<String, Object> map2 = new HashMap<String, Object>();
    map2.put("类型", "中");
    map2.put("数量", "少");
    map2.put("单价", 20);
    map2.put("优惠", 0.42);

    Map<String, List<Object>> maps = new HashMap<String, List<Object>>();
    for(String key : map1.keySet()){
        List<Object> list = maps.get(key);
        if(list == null){
            maps.put(key, list = new ArrayList<Object>());
        }
        list.add(map1.get(key));
    }
    for(String key : map2.keySet()){
        List<Object> list = maps.get(key);
        if(list == null){
            maps.put(key, list = new ArrayList<Object>());
        }
        list.add(map2.get(key));
    }
    for(String key : maps.keySet()){
        System.out.println(key + ":" + maps.get(key));
    }
}

输出为：

单价:[100, 20]
优惠:[0.12, 0.42]
类型:[大, 中]
数量:[多, 少]