package factory;

//Main.java
//=========

public class Main
{
    public static void main(String[] args) 
    {
        Select factory = new Select();
        Writer w = factory.getWriter();
        w.write("hello","guy");
    }
}


// Select.java
// ===========


public class Select 
{
    public Writer getWriter()
    {
        Math math = new Math();
        if(math.write(math._msg1,math._msg2) == true)
        {
            return new Math();
        }
        
        else 
        {
            return new Text();
        }
    }
}


// Writer <Interface>
// ==================

package factory;

public interface Writer 
{
    public boolean write(String msg1, String msg2);
}




// Math.java
// =========
package factory;

public class Math implements Writer
{
     protected String _msg1;
     protected String _msg2;
     
     public boolean write(String msg1, String msg2)
    {
        _msg1 = msg1;
        _msg2 = msg2;
        
         try  
        {  
            Integer.parseInt(_msg1);
            Integer.parseInt(_msg2);
            return true;
        }
        
         catch (NumberFormatException ex)
        {
            return false;
        }
    }
}
    

// Text.java
// =========

package factory;

public class Text implements Writer
{
    public boolean write(String msg1, String msg2)
    {
        return false;
    }
}