Calling class methods by class object using Reflection

[vikash talanki]

hi all,

I am creating & compiling(using ant script) java classes at runtime in my java program. In the same program I wanna get the objects for these classes and set their varibales/methods with some values.

Suppose I have a class like

class myclass
{
  int i;
  void getVar()
  {
     System.out.println(i);
  }
}

From my main java program I can easily set or call the method of myclass like

class mainPgm
{
  P.S.V.main(String args[])
  {
     myclass mc=myclass();
     mc.i=4;
     mc.getVar();
  }
}

The above code is trivial if we already know everything about "myclass". But if I want to get the instance of myclass at runtime & call methods of the class , I am totally confused & struck at this point, I can say

class mainPgm
{
  P.S.V.main(String args[])
  {
     Class myClass = Class.forName("myclass");
     myObject = myClass.newInstance();
    // Now How shud i call the getVar method or Variable i using myObject??????????????	

Please help

[Vijay Tidake]

Hi,

Look for the concept of type casting.
For your eg. you can call getVar() as follows.

                Class myClass = Class.forName("myclass");
		myclass myobj = (myclass) myClass.newInstance();
		myobj.i = 54;
		myobj.getVar();

Thanks

[Jigar Gohil]

I suggest you read the concept of Reflection in detail... there are methods available for fetching the methods & variables...

[vikash talanki]

@vijay Tidke

The probelm here is to get methods of class & then invoke them using object. According to your solution we need to know that there is method called getVar present in the class, what if we dont have idea of what methods are present in the class?

[Vijay Tidake]

Hi

for that you must go for the further reading on Java introspection and reflection.
Have a look at the java.beans.Introspector class.

Thanks

[Rob Spoor]

http://download.oracle.com/javase/tutorial/reflect/index.html