your class is not implementing actionPerformed() method
Remove 'A' with 'a' in actionperformed of DEcBtnAl and EncBtnAl.you are not
implementing that ,it is treat that class as an abstract
Thanks
kavitha
>From: RVASUDEV <[EMAIL PROTECTED]>
>Reply-To: "A mailing list for discussion about Sun Microsystem's Java
> Servlet API Technology." <[EMAIL PROTECTED]>
>To: [EMAIL PROTECTED]
>Subject: Partly off-topic: Q on inner classes/ActionListener
>Date: Tue, 26 Oct 1999 06:20:01 -0700
>
>Hi
>
>[Platform: Win NT 4.0 SP3, Sun JDK 1.2.2]
>
>While compiling a java application, I get some
>errors. App and err details below. Any suggestions
>appreciated. [The program is a simple one to
>encode/decode a file, the encode/decode logic
>hasn't been added yet]
>
>TIA
>Vasudev
>
>The application :
>
>-------------------------------------------------
>// Codec1.java
>
>import java.awt.*;
>import java.awt.event.*;
>import java.io.*;
>
>public class Codec1 extends Frame {
>
> /** initialize fields */
> Label inFileLabel = new Label("Input file name");
> TextField inFileName = new TextField(64);
> Label outFileLabel = new Label("Output file name");
> TextField outFileName = new TextField(64);
> Button encodeBtn = new Button("Encode");
> Button decodeBtn = new Button("Decode");
> Button exitBtn = new Button("Exit");
> TextField status = new TextField(64);
> FileInputStream fis;
> BufferedInputStream bis;
> DataInputStream dis;
> FileOutputStream fos;
> BufferedOutputStream bos;
> DataOutputStream dos;
>
> /** main - just creates a new Codec1 object */
> public static void main(String[] args) {
> new Codec1();
> }
>
> /* no-arg constructor */
> public Codec1() {
>
> super("Codec1");
>
> // setup GUI
> setLayout(new FlowLayout());
> add(inFileLabel);
> add(inFileName);
> add(outFileLabel);
> add(outFileName);
> add(encodeBtn);
> add(decodeBtn);
> add(exitBtn);
> add(status);
>
> // add listeners
> encodeBtn.addActionListener(new EncBtnAL());
> decodeBtn.addActionListener(new DecBtnAL());
> exitBtn.addActionListener(new ExiBtnAL());
>
> enableButtons();
> this.setSize(400, 500);
> this.setVisible(true);
> this.show();
>
> }
>
> /** listener for Encode Button */
> public class EncBtnAL implements ActionListener {
> public void ActionPerformed(ActionEvent ae) {
> disableButtons();
> status.setText("Encoding...please wait");
> encode( inFileName.getText().trim(),
> outFileName.getText().trim() );
> enableButtons();
> }
> }
>
> /** listener for Decode Button */
> public class DecBtnAL implements ActionListener {
> public void ActionPerformed(ActionEvent ae) {
> //disableButtons();
> status.setText("Not implemented yet");
> // decode(inFileName.getText(),
> //outFileName.getText());
> //enableButtons();
> }
> }
>
> /** listener for Encode Button */
> public class ExiBtnAL implements ActionListener {
> public void actionPerformed(ActionEvent ae) {
> System.out.println("Exiting...");
> sleep(1);
> System.exit(0);
> }
> }
>
> public void encode(String inFileName, String outFileName) {
> try {
> fis = new FileInputStream(inFileName);
> bis = new BufferedInputStream(fis);
> dis = new DataInputStream(bis);
> fos = new FileOutputStream(outFileName);
> bos = new BufferedOutputStream(fos);
> dos = new DataOutputStream(bos);
> char c;
> while ((c = dis.readChar()) != -1) {
> //c = c ^ c;
> dos.writeChar((int) c);
> }
> status.setText("Encoding complete");
> sleep(1);
> }
> catch(IOException ioe) {
> System.out.println("IO error: " + ioe);
> status.setText("Encode failed");
> sleep(1);
> }
> finally {
> try {
> dis.close(); bis.close(); fis.close();
> dos.close(); bos.close(); fos.close();
> }
> catch(IOException ioe) {
> System.out.println("IO error: " + ioe);
> status.setText("Close(s) failed");
> sleep(1);
> }
> }
> }
>
> public void disableButtons() {
> encodeBtn.setEnabled(false);
> decodeBtn.setEnabled(false);
> exitBtn.setEnabled(false);
> }
>
> public void enableButtons() {
> encodeBtn.setEnabled(true);
> decodeBtn.setEnabled(true);
> exitBtn.setEnabled(true);
> }
>
> public void sleep(int seconds) {
> try {
> Thread.sleep(seconds * 1000);
> }
> catch(InterruptedException ie)
> {
> }
> }
>}
>-------------------------------------------------
>
>
>The errors :
>
>C:> javac Codec1.java 2>e
>C:> type e
>
>Codec1.java:47: inner class Codec1. EncBtnAL is an abstract class. It can't
>be instantiated.
> encodeBtn.addActionListener(new EncBtnAL());
> ^
>Codec1.java:48: inner class Codec1. DecBtnAL is an abstract class. It can't
>be instantiated.
> decodeBtn.addActionListener(new DecBtnAL());
> ^
>Codec1.java:59: inner class Codec1. EncBtnAL must be declared abstract. It
>does not define void actionPerformed(java.awt.event.ActionEvent) from
>interface java.awt.event.ActionListener.
> public class EncBtnAL implements ActionListener {
> ^
>Codec1.java:70: inner class Codec1. DecBtnAL must be declared abstract. It
>does not define void actionPerformed(java.awt.event.ActionEvent) from
>interface java.awt.event.ActionListener.
> public class DecBtnAL implements ActionListener {
> ^
>4 errors
>
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