everything is working fine except Encryption button.

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;


public class encryption extends JPanel implements ActionListener {

   char [] str= {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z' };
   char [] str1={'1','2','3','4','5','6','7','8','9','0','!','@','#','$','%','^','&','*','(','_','_','+','=',',','.','?'};
   char [] a= new char [50];
   char [] b= new char [50];
   JLabel pt, et,dt;
   String k="";
    String l="";

   JTextField pf,ef,df;
   JButton encbutt, clebutt,decbutt,exibutt;





   public encryption(){

       pt=new JLabel("Plain Text");
          et=new JLabel("Encrypted Text");
          dt=new JLabel("Decrypted Text");

         pf= new JTextField(20);

        ef= new JTextField(20);

        df= new JTextField(20);

         encbutt= new JButton("Encryption");

        clebutt= new JButton("Clear");

          decbutt= new JButton("Decryption");

         exibutt= new JButton("Exit");

         ef.setEditable(false);
   df.setEditable(false);
     decbutt.setEnabled(false);

      setLayout(null);
       add(pt);
                add(et);
                add(dt);
                add(pf);
                add(ef);
                add(df);
                add(encbutt);
                add(clebutt);
                add(decbutt);

                add(exibutt);


      pt.setBounds(20, 20, 200,30);

        et.setBounds(20,80,200,30);

         dt.setBounds(20,140, 200,30);

          pf.setBounds(220,20,200,30);

           ef.setBounds(220,80,200,30);

            df.setBounds(220,140,200,30);

             encbutt.setBounds(30,200,160,30);

              clebutt.setBounds(30,240,160,30);

               decbutt.setBounds(240,200,160,30);

                exibutt.setBounds(240,240,160,30);


                decbutt.addActionListener(this);



                clebutt.addActionListener(this);

                exibutt.addActionListener(this);







   }



public void actionPerformed(ActionEvent ae)
 {
    String action=ae.getActionCommand();
    if(ae.equals("Encryption"))
    {
         k=pf.getText().toString().toLowerCase();
        if(k.equals(""))
        {
            pf.setFocusable(true);
            JOptionPane.showMessageDialog(this, "Please Enter Any text !", "Warning", JOptionPane.WARNING_MESSAGE);

        }
 else
        {
        decbutt.setEnabled(true);
        encbutt.setEnabled(false);


        a=k.toCharArray();
        for(int i=0;i<k.length();i++)
        {
            for(int j=0;j<26;j++)
            {
             if(a[i]==str[j])
             {
                 a[i]=str1[j];

             }
            }

        }
        for(int i=0;i<k.length();i++)
        {
          l=l+a[i] ;
        }
        ef.setText(l);


       // JOptionPane.showMessageDialog(bencrypt,l.toString(),"Message",JOptionPane.INFORMATION_MESSAGE);

    }
  }
 else if(action.equals("Decryption"))
    {
  String x=ef.getText().toString();
  String y="";
  if(x.equals(""))
  {
      JOptionPane.showMessageDialog(this,"No Encrypted Message","Warning",JOptionPane.WARNING_MESSAGE);
  }
 else
  {
  b=x.toCharArray();
   //JOptionPane.showMessageDialog(this,k.toString(),"Warning",JOptionPane.WARNING_MESSAGE);
  for(int i=0;i<x.length();i++)
  {
      for(int j=0;j<26;j++)
      {
      if(b[i]==str1[j])
      {
          b[i]=str[j];
          j=26;
      }
      }
  }
  for( int i=0;i<x.length();i++)
  {
      y=y+b[i];
  }
  df.setText(y);
  y="";
 }
 }
 else if(action.equals("Clear"))
    {

     pf.setText("");
     ef.setText("");
     df.setText("");
     pf.setFocusable(true);
     decbutt.setEnabled(false);
     encbutt.setEnabled(true);

    }
 else if(action.equals("Exit"))
    {
     System.exit(0);
 }
}

public static void main(String[] args) {


       JFrame n=new JFrame();
        n.getContentPane().add(new encryption());
        n.setSize(440,310);
        n.setVisible(true);
        n.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}


}

not working fine ...

can you specify this a bit ? Does it run ? Does it run the code for that button or not ? Does it produce different output ?
What do you expect ? What do you get ?

Have you tried debugging it ?
Is the code you've written according to your requirements ? What are your requirements ?

when i type something and click at Encryption button. I don't get encrypted text.other buttons are working fine except this one.

shouldnt line 108 be
if(action.equals("Encryption")) instead of if(ae.equals("Encryption"))

even if you change that.It's still not working

and have you tried debugging your code ?
"I don't get encrypted text". do you get other output, does it run that code at all ? there still are to many questions you haven't looked into yet.

As i said before all buttons are working fine (clear, decrypted, exit)except encrypted button and when i debug i don't get any error.

That's still a useless description of your problem.

But anyway - if you were to add an action listener to that button it may help.

commented: nice catch +13

ps
That style of having one giant actionPerformed is a horrible hard-to-read error-prone hang-over from the Java of 10 years ago. In 2015 it’s far better to use the facilities of modern Java and just have one method for each button, linked by a trivial lambda, e.g.

JButton buttonA, buttonB;
…

buttonA.addActionListener(this::buttonAClicked);
buttonB.addActionListener(this::buttonBClicked);

...

void buttonAClicked(ActionEvent e) {
    // handle click on button A
}

void buttonBClicked(ActionEvent e) {
    // handle click on button B
}

(the method names can be anything you like)