如何在java中创建嵌套的HashMap

Question

我正在尝试将匿名hashmap放入另一个hashmap： -

Map<String, Object> requestBody=new HashMap<String, Object>();
requestBody.put("UPSSecurity", new HashMap<String, Object>().put("username","rohan"));
System.out.println(requestBody);

输出是： -

{UPSSecurity=null}

Answer 1

请使用这种方式来定义嵌套的Hashmap。

    Map<String, Object> requestBody=new HashMap<String, Object>();
    Map<String,Object> userdetails=new HashMap<String, Object>();
    userdetails.put("username","rohan");
    requestBody.put("UPSSecurity",userdetails );
    System.out.println(requestBody);

输出：

  

{UPSSecurity = {用户名=罗汉}}

Answer 2

你也可以这样做。

Map<String, Object> requestBody=new HashMap<String, Object>();
requestBody.put("UPSSecurity", new HashMap<String, Object>());
requestBody.get("UPSSecurity").put("username","rohan");