Java中常见的Map操作方法有哪些呢?

1、创建Map几种方式

常用创建Map对象

	Map<String, String> myMap = new HashMap<String, String>();  
	myMap.put("a", "b");  
	myMap.put("c", "d");
    
java8新特性–双括号初始化

	HashMap<String, String > myMap  = new HashMap<String, String>(){{  
		  put("a","b");  
		  put("b","b");       
	}};  

java9新特性–最简便的方式
    Map.of("Hello", 1, "World", 2);//不可变集合

Guava
    Map<String, Integer> myMap = ImmutableMap.of("a", 1, "b", 2, "c", 3); 

2、Map转JSONstring

<dependency>
   <groupId>com.alibaba</groupId>
   <artifactId>fastjson</artifactId>
   <version>1.2.24</version>
</dependency>

  
Map map=new HashMap();
map.put("key1","10");
map.put("key2","1");
String  param= JSON.toJSONString(map);