[java] Call a Class From another class

I want to call class2 from class1 but class2 doesn't have a main function to refer to like Class2.main(args);

Suposse you have

Class1

public class Class1 {
    //Your class code above
}

Class2

public class Class2 {
}

and then you can use Class2 in different ways.

Class Field

public class Class1{
    private Class2 class2 = new Class2();
}

Method field

public class Class1 {
    public void loginAs(String username, String password)
    {
         Class2 class2 = new Class2();
         class2.invokeSomeMethod();
         //your actual code
    }
}

Static methods from Class2 Imagine this is your class2.

public class Class2 {
     public static void doSomething(){
     }
}

from class1 you can use doSomething from Class2 whenever you want

public class Class1 {
    public void loginAs(String username, String password)
    {
         Class2.doSomething();
         //your actual code
    }
}

Class2 class2 = new Class2();

Instead of calling the main, perhaps you should call individual methods where and when you need them.

Simply create an instance of Class2 and call the desired method.

Suggested reading: http://docs.oracle.com/javase/tutorial/java/javaOO/

First create an object of class2 in class1 and then use that object to call any function of class2 for example write this in class1

class2 obj= new class2();
obj.thefunctioname(args);

If your class2 looks like this having static members

public class2
{
    static int var = 1;

    public static void myMethod()
    {
      // some code

    }
}

Then you can simply call them like

class2.myMethod();
class2.var = 1;

If you want to access non-static members then you would have to instantiate an object.

class2 object = new class2();
object.myMethod();  // non static method
object.var = 1;     // non static variable