Creating complex HashMap in Java

Question

What is the easiest way to create a HashMap like this : ``` ( student1 => Map( name => Tim, Scores => Map( math => 10, physics => 20, Computers => 30), place => Miami, ranking => Array(2,8,1,13), ), student2 => Map ( ............... ............... ), ............................ ............................ ); ``` I tried this : ``` HashMap record = new HashMap(); record.put("student1", new HashMap()); record.get("student1").put("name","Tim"); record.get("student1").put("Scores", new HashMap()); ``` But I get error. I do it that way because, `record.get("student1")` is a HashMap object, so I assume a `put` on that should work, and so on. If it doesnt work, what is the best way to do it ?

Accepted Answer

You get that exception because `get()` returns a type `Object`. you need to cast that to a `Map`.

```
((Map)record.get("student1")).put("name","Tim");
```

Creating complex HashMap in Java

Solution

Problem