Map解析

文档地址：
中文：https://aisia.moe/java6api-cn/index.html?javax/xml/ws/handler/MessageContext.html
原文：https://docs.oracle.com/javase/8/docs/api/java/util/Map.html

1.SimpleBindings<String,Object>,key必须是String,否则会报，且要非null，非""，否则报错。

        if (key == null) {
            throw new NullPointerException("key can not be null");
        }
        if (!(key instanceof String)) {
            throw new ClassCastException("key should be a String");
        }
        if (key.equals("")) {
            throw new IllegalArgumentException("key can not be empty");
        }

2.ConcurrentSkipListMap的讲解：https://blog.****.net/vickyway/article/details/49507615
3.EnumMap:

enum Color{
		red,yellow
	}
	EnumMap<Color,Object> enumMap= new EnumMap<>(Color.class);