Possible Duplicate:
Use string in place of variable name
Is there any way in Java that allows an object to be created using a string?
Let's say, i have a class called "Toyata", is there anyway i can create an object of Toyata using the string variable s in class Car?
public class Car{
String s = "Toyota";
}
public class Toyota{
int speed;
public Toyota(int speed){
this.speed=speed;
}
}
You can use reflection, but you need a fully qualified classname:
https://stackoverflow.com/a/4030634/1217408
EDIT:
Hovercraft Full Of Eels's comment about using a map lookup is probably far more appropriate in this situation.
You need to query for class (assuming it's in the default package this should work) via the value of s. Then you have to lookup the proper constructor via your class' getConstructor() method. Since Toyota does not contain a default constructor, you need to query for one that matches your expected parameters. In this case, it's an int. int is represented in Class form by Integer.TYPE. Finally after that is all said and done, you can call newInstance() on the constructor with the desired speed passed in and you should have a new instance ready to use. Of course there will be a few checked exceptions to handle.
Class<?> clazz = Class.forName(s);
Constructor constructor = clazz.getConstructor(new Class[] {Integer.TYPE});
Toyota toyota = (Toyota) constructor.newInstance(new Object[] {90});
Map<String, OtherType>. This question should be closed as it has been asked and answered thousands of times before. Please Google this and you'll see.public class Toyota implements Car. If there's any generic implementation, you may want to extendGenericCarclass:public class Toyota extends GenericCar, wherepublic class GenericCar implements Car. Not really answer to your question, but it may be you are on the wrong track here.