Aendererer.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package reverse_eingabe;

/**
 *
 * @author B201
 */
public interface Aendererer {
    
    public String manipuliere(String eingabe);
        
    
    
    
}

gistfile1.txt

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package reverse_eingabe;

/**
 *
 * @author B201
 */
public class Marlon implements Aendererer{

    @Override
    public String manipuliere(String eingabe) {
       String newString = eingabe+"!";
       return newString;
        
    }

 
    
}

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package reverse_eingabe;

/**
 *
 * @author B201
 */
public class Reverse implements Aendererer{

    @Override
    public String manipuliere(String eingabe) {
       
        String newString = eingabe;
        StringBuilder sb = new StringBuilder(newString);
     String newnewString = sb.reverse().toString();
       
       return newnewString;
        
    }


    
}

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package reverse_eingabe;

/**
 *
 * @author B201
 */
public class Reverse_eingabe {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
  GUI gui = new GUI();
  gui.start();
  
    }
    
}

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package reverse_eingabe;

/**
 *
 * @author B201
 */
public class UpperDowner implements Aendererer{

    @Override
    public String manipuliere(String eingabe) {
        
             String toggled = ""; 
       for(int i=0; i<eingabe.length(); i++)
       {


           char letter = eingabe.charAt(i); 

           if(Character.isUpperCase(eingabe.charAt(i)))
           {
                letter = Character.toLowerCase(letter); 
                toggled = toggled + letter; 

           }
           else if(Character.isLowerCase(eingabe.charAt(i)))
           {
               letter = Character.toUpperCase(letter);
               toggled = toggled + letter; 
           }
    }
       return toggled;

  
}
}

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package reverse_eingabe;

/**
 *
 * @author B201
 */
public interface Aendererer {
    
    public String manipuliere(String eingabe);
        
    
    
    
}

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package reverse_eingabe;

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;

/**
 *
 * @author B201
 */
class GUI {
 
    JFrame frame;
    JTextField eingabeFeld;
    JButton knopf;
    JComboBox box;
    JLabel anzeige;
    int conboindex = 0; 
    public void start() {
       
        
        frame = new JFrame();
        frame.setLayout(new GridLayout(0,1));
        
        eingabeFeld = new JTextField();
        frame.add(eingabeFeld);
        
        anzeige = new JLabel();
        frame.add(anzeige);
        box = new JComboBox();
        box.addItem("Reverse");
        box.addItem("Marlon");
        box.addItem("UpperDowner");
        box.addItemListener(new ItemListener1());
        
        frame.add(box);
        knopf = new JButton();
        knopf.setAction(new Pressing());
        knopf.setText("Umkehren");
        frame.add(knopf);
        
        
        frame.setVisible(true);
        frame.pack();
        
        
        
    }


    public class ItemListener1 implements java.awt.event.ItemListener {

        @Override
        public void itemStateChanged(ItemEvent e) {
    int index =  box.getSelectedIndex();
  conboindex = index;
  
         
        }
    }

    private class Pressing extends AbstractAction {
String newString;
        @Override
        public void actionPerformed(ActionEvent e) {
  if(conboindex == 0) { //Reverse
      Reverse re = new Reverse();
      newString = re.manipuliere(eingabeFeld.getText());
     anzeige.setText(newString);
  } if(conboindex == 1) { //Marlon
        Marlon mar = new Marlon();
      newString = mar.manipuliere(eingabeFeld.getText());
     anzeige.setText(newString);
      
  }if(conboindex == 2) { //UpperDowner
      UpperDowner ud = new UpperDowner();
       newString = ud.manipuliere(eingabeFeld.getText());
     anzeige.setText(newString);
      
  }
                
            
                    
            
            
            
        }

    }
    
}

GUI.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package reverse_eingabe;

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;

/**
 *
 * @author B201
 */
class GUI {
 
    JFrame frame;
    JTextField eingabeFeld;
    JButton knopf;
    JComboBox box;
    JLabel anzeige;
    int conboindex = 0; 
    public void start() {
       
        
        frame = new JFrame();
        frame.setLayout(new GridLayout(0,1));
        
        eingabeFeld = new JTextField();
        frame.add(eingabeFeld);
        
        anzeige = new JLabel();
        frame.add(anzeige);
        box = new JComboBox();
        box.addItem("Reverse");
        box.addItem("Marlon");
        box.addItem("UpperDowner");
        box.addItemListener(new ItemListener1());
        
        frame.add(box);
        knopf = new JButton();
        knopf.setAction(new Pressing());
        knopf.setText("Umkehren");
        frame.add(knopf);
        
        
        frame.setVisible(true);
        frame.pack();
        
        
        
    }


    public class ItemListener1 implements java.awt.event.ItemListener {

        @Override
        public void itemStateChanged(ItemEvent e) {
    int index =  box.getSelectedIndex();
  conboindex = index;
  
         
        }
    }

    private class Pressing extends AbstractAction {
String newString;
        @Override
        public void actionPerformed(ActionEvent e) {
  if(conboindex == 0) { //Reverse
      Reverse re = new Reverse();
      newString = re.manipuliere(eingabeFeld.getText());
     anzeige.setText(newString);
  } if(conboindex == 1) { //Marlon
        Marlon mar = new Marlon();
      newString = mar.manipuliere(eingabeFeld.getText());
     anzeige.setText(newString);
      
  }if(conboindex == 2) { //UpperDowner
      UpperDowner ud = new UpperDowner();
       newString = ud.manipuliere(eingabeFeld.getText());
     anzeige.setText(newString);
      
  }
                
            
                    
            
            
            
        }

    }
    
}

Marlon.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package reverse_eingabe;

/**
 *
 * @author B201
 */
public class Marlon implements Aendererer{

    @Override
    public String manipuliere(String eingabe) {
       String newString = eingabe+"!";
       return newString;
        
    }

 
    
}

Reverse.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package reverse_eingabe;

/**
 *
 * @author B201
 */
public class Reverse implements Aendererer{

    @Override
    public String manipuliere(String eingabe) {
       
        String newString = eingabe;
        StringBuilder sb = new StringBuilder(newString);
     String newnewString = sb.reverse().toString();
       
       return newnewString;
        
    }


    
}

Reverse_eingabe.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package reverse_eingabe;

/**
 *
 * @author B201
 */
public class Reverse_eingabe {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
  GUI gui = new GUI();
  gui.start();
  
    }
    
}

UpperDowner.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package reverse_eingabe;

/**
 *
 * @author B201
 */
public class UpperDowner implements Aendererer{

    @Override
    public String manipuliere(String eingabe) {
        
             String toggled = ""; 
       for(int i=0; i<eingabe.length(); i++)
       {


           char letter = eingabe.charAt(i); 

           if(Character.isUpperCase(eingabe.charAt(i)))
           {
                letter = Character.toLowerCase(letter); 
                toggled = toggled + letter; 

           }
           else if(Character.isLowerCase(eingabe.charAt(i)))
           {
               letter = Character.toUpperCase(letter);
               toggled = toggled + letter; 
           }
    }
       return toggled;

  
}
}