java中String，json，Map之间的转换

测试代码：

public static void main(String[] args) {
Map<String,String> map = new HashMap<String,String>();
map.put("a", "\"测试\"");
map.put("b", "\"f\"");
map.put("c", "\"3\"");
// map转str
String str1 = map.toString();
System.out.println("***" + str1);

// str转json
JSONObject json = JSONObject.fromObject(str1);
System.out.println("---" + json);

// json转map
Map map1 = (Map)json;
System.out.println("+++"+map1.toString());
System.out.println("+-*" + map1.get("a") );

}响应数据：
***{a="测试", b="f", c="3"}

---{"a":"测试","b":"f","c":"3"}

+++{"a":"测试","b":"f","c":"3"}

+-*测试