mixed_cipher

//package mixed_cipher;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.lang.String;
import javax.swing.*;
public class Mixed {
    static String pln = "abcdefghijklmnopqrstuvwxyz";
    public static void main(String[] args) {
        // TODO Auto-generated constructor stub
        JFrame frame = new JFrame("Mixed");
        frame.setLayout(new GridLayout(4, 2));
        frame.setSize(500, 150);
        JTextField plaintext = new JTextField();
        JTextField ciphertext = new JTextField();
        JLabel plaintxt = new JLabel("Plaintext");
        JLabel ciphertxt = new JLabel("Ciphertext");
        JLabel encrypted = new JLabel("Encrypted");
        JLabel decrypted = new JLabel("Decrypted");
        JButton encrypt = new JButton("Encrypt");
        JButton decrypt = new JButton("Decrypt");
        frame.add(plaintxt);
        frame.add(plaintext);
        frame.add(ciphertxt);
        frame.add(ciphertext);
        frame.add(encrypt);
        frame.add(encrypted);
        frame.add(decrypt);
        frame.add(decrypted);
        frame.setVisible(true);
        encrypt.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent arg0) {
                String plain = plaintext.getText().toString();
                String cph = ciphertext.getText().toString();
                String ciph = "";
                String encpt = "";
                for(int i = 0; i < cph.length(); ++i) {
                    if(ciph.indexOf(cph.charAt(i)) == -1){
                        ciph += cph.charAt(i);
                    }
                }
                for(int i = 0; i < pln.length(); ++i) {
                    if(ciph.indexOf(pln.charAt(i)) == -1){
                        ciph += pln.charAt(i);
                    }
                }
                for(int i = 0; i < plain.length(); ++i) {
                    encpt += ciph.charAt(pln.indexOf(plain.charAt(i)));
                }
                encrypted.setText(encpt);
            }
        });
        decrypt.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent arg0) {
                // TODO Auto-generated method stub
                String cph = ciphertext.getText().toString();
                String ciph = "";
                String decpt = "";
                for(int i = 0; i < cph.length(); ++i) {
                    if(ciph.indexOf(cph.charAt(i)) == -1){
                        ciph += cph.charAt(i);
                    }
                }
                for(int i = 0; i < pln.length(); ++i) {
                    if(ciph.indexOf(pln.charAt(i)) == -1){
                        ciph += pln.charAt(i);
                    }
                }
                for(int i = 0; i < encrypted.getText().length(); ++i) {
                    decpt += pln.charAt(ciph.indexOf(encrypted.getText().charAt(i)));
                }
                decrypted.setText(decpt);
            }
        });
    }
}