Question

How do i create a new instance of an object from a string?

I want to do this:

Event event = new Event("hello");  
event.setName("nice!");

but only having

String object = "Event";  
String object_variable_name = "event";  
String object_params = "hello";

Is this possible?

Answer 1

You can instantiate a class with the reflection API. But you need the full class name, the simple name (= with no constructor) is not enough.

Class clazz = Class.forName("com.example.Event");
Constructor constructor = clazz.getConstructor(String.class);
Object instance = constructor.newInstance("hello");

Assigning it to a variable where the variables name and type are stored in Strings is not possible. The usual pattern to implement this is to use a map:

Map<String, Object> events = new HashMap<String, Object>();
events.put("event", event);