Can i use a string variable as a datatype to create other variables in java

Question

I use reflection to invoke a method as:

method.invoke(someObject, null);

The problem is, I want to use the value that this method returns without having it's data type known before hand. I have the knowledge of the data type in a string variable, say

String type = "String";

Is it possible to do something equivalent of this-

type variable = method.invoke(someObject, null)

What exactly are you trying to achieve? Why not just return it to an Object? — Mureinik
– Mureinik, Commented May 21, 2015 at 14:57
I want to do type specific operation. For e.g. if it was an integer, I will check if it is less than 0. How will I achieve this if it is just of Object data type? — Abhishek Chauhan
– Abhishek Chauhan, Commented May 21, 2015 at 15:00
You must know something about the object coming in or else how do you know what method to invoke via reflection? — MadConan
– MadConan, Commented May 21, 2015 at 15:18
I believe this question has already been asked here: stackoverflow.com/questions/12286871/… — Emil
– Emil, Commented May 21, 2015 at 15:39

nuno · Accepted Answer · 2015-05-21 15:03:21Z

1

Check the Object type with instanceof.

Object o = method.invoke(...);
if(o instanceof Integer) {
    // Integer logic...
}
if(o instanceof YourType) {
    // YourType logic...
}
// and so on

answered May 21, 2015 at 15:03

nuno

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1 Comment

Abhishek Chauhan Over a year ago

Any non if way to do it?

D. Visser · Accepted Answer · 2015-05-21 15:16:27Z

0

Maybe something like this could work for you:

if(type.equals("String"){
    String o = (String) returnedObject;
} else if(type.equals("Integer")){
    Integer o = (Integer) returnedObject;
}

But I recommend not going down this road. There has to be some better way to achieve your desired result.

answered May 21, 2015 at 15:16

D. Visser

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1 Comment

Abhishek Chauhan Over a year ago

I also feel the same.

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