This program is well compiled but does not work.

Question

I would like to know why this program does not work properly:
the idea is :
1. the user introduces a text as a string
2.the progam creates a file (with a FileOutputStream)
3. then this file is encripted according to DES (using JCE, cipheroutputStream)
4.the new filw is an encripte file, whose content is introduced in a string (with a FileInputStream)
(gives no probles of compilation!!)
(don know why it does not work)
here goes the code:
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.io.*;
import java.security.*;
import javax.crypto.*;
public class cuadro extends Applet{
     private TextArea area1 =new TextArea(5,50);
     private TextArea area2 =new TextArea(5,50);
     private Button encriptar=new Button("encriptar");
     private Button decriptar=new Button("decriptar");
     public cuadro(){
          layoutApplet();
          encriptar.addActionListener(new ButtonHandler());
          decriptar.addActionListener(new ButtonHandler());
          resize(400,400);
          private void layoutApplet(){
          Panel keyPanel = new Panel();
          keyPanel.add(encriptar);
          keyPanel.add(decriptar);
          Panel textPanel = new Panel();
          Panel texto1 = new Panel();
          Panel texto2 = new Panel();
          texto1.add(new Label("               plain text"));
          texto1.add(area1);
          texto2.add(new Label("               cipher text"));
          texto2.add(area2);
          textPanel.setLayout(new GridLayout(2,1));
          textPanel.add(texto1);
          textPanel.add(texto2);
          setLayout(new BorderLayout());
          add("North", keyPanel);
          add("Center", textPanel);
          public static String encriptar(String text1){
          //generar una clave
          SecretKey clave=null;
          String text2="";
          try{
          FileOutputStream fs =new FileOutputStream ("c:/javasoft/ti.txt");
          DataOutputStream es= new DataOutputStream(fs);
               for(int i=0;i<text1.length();++i){
                    int j=text1.charAt(i);
                    es.write(j);
               es.close();
          }catch(IOException e){
               System.out.println("no funciona escritura");
          }catch(SecurityException e){
               System.out.println("el fichero existe pero es un directorio");
          try{
               //existe archivo DESkey.ser?
               ObjectInputStream claveFich =new ObjectInputStream(new FileInputStream ("DESKey.ser"));
               clave = (SecretKey) claveFich.readObject();
               claveFich.close();
          }catch(FileNotFoundException e){
               System.out.println("creando DESkey.ser");
               //si no, generar generar y guardar clave nueva
          try{
               KeyGenerator claveGen = KeyGenerator.getInstance("DES");
               clave= claveGen.generateKey();
               ObjectOutputStream claveFich = new ObjectOutputStream(new FileOutputStream("DESKey.ser"));
               claveFich.writeObject(clave);
               claveFich.close();
          }catch(NoSuchAlgorithmException ex){
               System.out.println("DES key Generator no encontrado.");
               System.exit(0);
          }catch(IOException ex){
               System.out.println("error al salvar la clave");
               System.exit(0);
     }catch(Exception e){
          System.out.println("error leyendo clave");
          System.exit(0);
     //crear una cifra
     Cipher cifra = null;
     try{
          cifra= Cipher.getInstance("DES/ECB/PKCS5Padding");
          cifra.init(Cipher.ENCRYPT_MODE,clave);
     }catch(InvalidKeyException e){
          System.out.println("clave no valida");
          System.exit(0);
     }catch(Exception e){
          System.out.println("error creando cifra");
          System.exit(0);
     //leer y encriptar el archivo
     try{
          DataInputStream in = new DataInputStream(new FileInputStream("c:/javasoft/ti.txt"));
          CipherOutputStream out = new CipherOutputStream(new DataOutputStream(new FileOutputStream("c:/javasoft/t.txt")),cifra);
          int i;
          do{
               i=in.read();
               if(i!=-1) out.write(i);
          }while (i!=-1);
          in.close();
          out.close();
     }catch(IOException e){
          System.out.println("error en lectura y encriptacion");
          System.exit(0);
     try{
          FileInputStream fe=new FileInputStream("c:/javasoft/t.txt");
          DataInputStream le =new DataInputStream(fe);
               int i;
               char c;
               do{
                    i=le.read();
                    c= (char)i;
                    if(i!=-1){
                    text2 += text2.valueOf(c);
               }while(i!=-1);
                    le.close();
          /*}catch(FileNotFoundException e){
               System.out.println("fichero no encontrado");
               System.exit(0);
          }catch(ClassNotFoundException e){
               System.out.println("clase no encontrada");
               System.exit(0);
          */}catch(IOException e){
               System.out.println("error e/s");
               System.exit(0);
          return text2;
     class ButtonHandler implements ActionListener{
     public void actionPerformed(ActionEvent e){
          try{
          if (e.getActionCommand().equals(encriptar.getLabel()))
               //     area2.setText(t1)
               area2.setText(encriptar(area1.getText()));
               //area2.setText("escribe algo");
               else if (e.getActionCommand().equals(decriptar.getLabel()))
                    System.out.println("esto es decriptar");
                    //area2.setText("hola");
     }catch(Exception ex){
          System.out.println("error en motor de encriptacion");
               //else System.out.println("no coge el boton encriptado/decript");

Answer 1

If you don't require your code to run as an applet, you will probably get more mileage from refactoring it to run as an application.
As sudha_mp implied, an unsigned applet will fail on the line
FileInputStream fe=new FileInputStream("c:/javasoft/t.txt");
due to security restrictions. (Which, incidentally, are there for a very good reason)