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?
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);
You can use java.lang.Class's getConstructor isnstead.
Here is how you get the class instance (so you can call the constructor): How to get a Class Object from the Class Name in Java
Now you can you the Beans API to get the getter for the property name. See this question: Java Reflection: Instantiate a new object with specified type
Or you can use reflectasm or reflections or commons-beanutils to make your life much more simple
