Determining and invoking methods of a class

[s16kumar]

Hi,,
I am new to programming languages..

I want this problem to be resolved.

Consider a situation of three class.. C1, C2 & C3.

Class C3 has a method that receives the object as the arguement.

class C3 {
public void xxxxx(Object ob)
}

I want the arguement of the method to be capable of taking the object of any class and display/call the methods of the class object that is passed to the method.

For eg: if C1 object is passed first time.. thn the methods of C1 should be able to access..

if C2 object is passed next time. thn the methods of C2 should be able to access..

I thank you in advance for solving my problem

[madhoriya22]

Hi,,
I am new to programming languages..

I want this problem to be resolved.

Consider a situation of three class.. C1, C2 & C3.

Class C3 has a method that receives the object as the arguement.

class C3 {
public void xxxxx(Object ob)
}

I want the arguement of the method to be capable of taking the object of any class and display/call the methods of the class object that is passed to the method.

For eg: if C1 object is passed first time.. thn the methods of C1 should be able to access..

if C2 object is passed next time. thn the methods of C2 should be able to access..

I thank you in advance for solving my problem

Hi,
Collect ur object in object of class Object. Inside method check

 
if(ob instanceOf C1) {
 
//call C1 class method
}else if(ob instanceOf C2) {
 
//call C2 class method
}else if(ob instanceOf C3) {
 
//call C3 class method
}
 

This way you can do it. :)

[Nepomuk]

Hi,,
I am new to programming languages..

I want this problem to be resolved.

Consider a situation of three class.. C1, C2 & C3.

Class C3 has a method that receives the object as the arguement.

class C3 {
public void xxxxx(Object ob)
}

I want the arguement of the method to be capable of taking the object of any class and display/call the methods of the class object that is passed to the method.

For eg: if C1 object is passed first time.. thn the methods of C1 should be able to access..

if C2 object is passed next time. thn the methods of C2 should be able to access..

I thank you in advance for solving my problem

Hi s16kumar! Welcome to TSDN!
Do I understand you correctly, you want to have three classes like this:

public class C1 {
   public void doSomething()
   {
      System.out.println("Hi, this is C1.doSomething()!");
   }
}
 

public class C2 {
   public void doSomethingElse()
   {
      System.out.println("Hi, this is C2.doSomethingElse()!");
   }
}
 

public class C3 {
   private Object myObject;
   public void setObject(Object obj)
   {
      myObject = obj;
   }
   public void useObject(String method)
   {
      // use the method "method" from myObject
   }
}
 

Is that correct? If so, maybe getClass and getDeclaredMethod might help. (They look like it, but I haven't tested them yet.)

Greetings,
Nepomuk

[Nepomuk]

Hi,
Collect ur object in object of class Object. Inside method check

 
if(ob instanceOf C1) {
 
//call C1 class method
}else if(ob instanceOf C2) {
 
//call C2 class method
}else if(ob instanceOf C3) {
 
//call C3 class method
}
 

This way you can do it. :)

That will work, as long as you only have those two methods (C1 and C2) that you'll want to call with your code. My solution should work for any Object (I hope).

Greetings,
Nepomuk

[s16kumar]

Hi,
Collect ur object in object of class Object. Inside method check

 
if(ob instanceOf C1) {
 
//call C1 class method
}else if(ob instanceOf C2) {
 
//call C2 class method
}else if(ob instanceOf C3) {
 
//call C3 class method
}
 

This way you can do it. :)

Thanks for your reply.

But the problem is i dont know as to how many and wht are the class that i need to check with the object.(Like in this case.. its C1 and C2 are known)..

How do i generally have an object.. which can invoke the methods of the class that is passed to it.. at runtime..

Eagerly waiting for ur valuable reply..

[Nepomuk]

Thanks for your reply.

But the problem is i dont know as to how many and wht are the class that i need to check with the object.(Like in this case.. its C1 and C2 are known)..

How do i generally have an object.. which can invoke the methods of the class that is passed to it.. at runtime..

Eagerly waiting for ur valuable reply..

Check my answer (#3) for that - it should work. If you have problems with it, ask specific questions.

Greetings,
Nepomuk

[r035198x]

If you know the names of the classes and the methods you want to call on them then just test the type using instanceOf and cast the Objects to the relevant class before calling the methods. Otherwise you may need to play around with reflection.

[madhoriya22]

Check my answer (#3) for that - it should work. If you have problems with it, ask specific questions.

Greetings,
Nepomuk

Hi Nepomuk,
Nice description buddy .. You are correct! .. My solution was not generalized :)

[Nepomuk]

Hi Nepomuk,
Nice description buddy .. You are correct! .. My solution was not generalized :)

Hi Madhoriya! I do my best! ^^

[s16kumar]

Hi guys..

The reply was right.. But after i accept the object of the class in the object of type Object. The problem is after that i am not able to call the methods of the class object passed to it. The method getClass() gives me the name of the orignal class.. and the method getDeclaredMethod also does not help..

Thank you,..

[madhoriya22]

Hi guys..

The reply was right.. But after i accept the object of the class in the object of type Object. The problem is after that i am not able to call the methods of the class object passed to it. The method getClass() gives me the name of the orignal class.. and the method getDeclaredMethod also does not help..

Thank you,..

Hi,
Can show through some relevant code that how you are doing this ?

[r035198x]

Use reflection

[s16kumar]

Lets consider the following example..

1)
Classs Customer{
string custName;
public Customer(String name) {
this.custName = name;
}
public String getCustName(){
return this.cusName;
}
}

2)Class Abc{
Customer c1 = new Customer("John");
MainFile mf = new MainFile();
mf.sample(c1);

3)

Class MainFile{
public void sample(Object ob){
// Now i want to call the methods of the class Customer..
// Here i dont know if the object ob has the object of the class Customer or some other classs.. what ever class's object ob has.. it should call those methods.. The mainFile class does not know which class object is passed..

}

Plz Let me know if this info is fine...

[r035198x]

Lets consider the following example..

1)
Classs Customer{
string custName;
public Customer(String name) {
this.custName = name;
}
public String getCustName(){
return this.cusName;
}
}

2)Class Abc{
Customer c1 = new Customer("John");
MainFile mf = new MainFile();
mf.sample(c1);

3)

Class MainFile{
public void sample(Object ob){
// Now i want to call the methods of the class Customer..
// Here i dont know if the object ob has the object of the class Customer or some other classs.. what ever class's object ob has.. it should call those methods.. The mainFile class does not know which class object is passed..

}

Plz Let me know if this info is fine...

1.) Use code tags everytime when posting code.
2.) I was going to ask you to use reflection but I've already done that.

[Nepomuk]

I've been experimenting and here's a working example:

import java.lang.reflect.Method;
 
public class C3 {
 
    public static void main(String[] args) {
        C1 c1 = new C1();
        C2 c2 = new C2();
        useClass(c1, "doSomething");
        useClass(c2, "doSomethingElse");
        useClass(c2, "doSomethingThird");
    }
    private static void useClass(Object obj, String method)
    {
        try
        {
            Class params[] = {};
            Method meth = obj.getClass().getDeclaredMethod(method, params);
            Object paramsObj[] = {};
            meth.invoke(obj, paramsObj);
        }
        catch(NoSuchMethodException nsme)
        {
            System.out.println("No method " + method + " in " + obj.getClass());
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }
}
class C1 {
    void doSomething()
    {
        System.out.println("Using C1.doSomething()");
    }
}
class C2 {
    void doSomethingElse()
    {
        System.out.println("Using C2.doSomethingElse()");
    }
    void doSomethingThird()
    {
        System.out.println("Using C2.doSomethingThird()");
    }
}
 

If you need help understanding it, do ask!
Just hope, it's not considered to much spoon feeding. ^^ If so, a Admin may feel free to delete it.

Greetings,
Nepomuk

[r035198x]

I've been experimenting and here's a working example:

import java.lang.reflect.Method;
 
public class C3 {
 
    public static void main(String[] args) {
        C1 c1 = new C1();
        C2 c2 = new C2();
        useClass(c1, "doSomething");
        useClass(c2, "doSomethingElse");
        useClass(c2, "doSomethingThird");
    }
    private static void useClass(Object obj, String method)
    {
        try
        {
            Class params[] = {};
            Method meth = obj.getClass().getDeclaredMethod(method, params);
            Object paramsObj[] = {};
            meth.invoke(obj, paramsObj);
        }
        catch(NoSuchMethodException nsme)
        {
            System.out.println("No method " + method + " in " + obj.getClass());
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }
}
class C1 {
    void doSomething()
    {
        System.out.println("Using C1.doSomething()");
    }
}
class C2 {
    void doSomethingElse()
    {
        System.out.println("Using C2.doSomethingElse()");
    }
    void doSomethingThird()
    {
        System.out.println("Using C2.doSomethingThird()");
    }
}
 

If you need help understanding it, do ask!
Just hope, it's not considered to much spoon feeding. ^^ If so, a Admin may feel free to delete it.

Greetings,
Nepomuk

What would really help the OP is to read a reflection tutorial. But they are ignoring me anyway ...

[Nepomuk]

What would really help the OP is to read a reflection tutorial. But they are ignoring me anyway ...

This one? Cause even if the OP doesn't read it, I'm interested...

Greetings,
Nepomuk