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GUI Program freezes once inside action performed method in java [duplicate]

This question already has answers here:
GUI Freezes During While Loop in Java
(1 answer)
The program freezes when i put a while loop in a action listener
(1 answer)
Closed 2 years ago.
I am attempting to redirect my system.out.println to dislpay to the JTextArea element of the GUI (hence it being public and static so that the methods that print something can print to it.
But once it gets to the line:
System.out.println("sdsdsdsdsa");
the program just does not go any further. The next two lines are:
System.setOut(printStream);
System.setErr(printStream);
which it does not seem to print out and when I exit the program this error appears:
"Exception: java.lang.NullPointerException thrown from the UncaughtExceptionHandler in thread "main""
and I am unable to verify whether printStream is null or not because the debugger does not seem to following into the action performed method once the start button (JButton1) is pressed.
Below is the main class in the GUI:
public class TrainingProgramme {
static PrintStream printStream = new PrintStream(new GUITextOutputStream(TrainingProgrammeGUI.jTextArea1));
public static void main(String[] args) {
TrainingProgrammeGUI gui = new TrainingProgrammeGUI();
gui.setVisible(true);
System.setOut(printStream);
System.setErr(printStream);
System.out.println("==================================\n"+
"* WELCOME TO CATCH ME IF YOU CAN *\n"+
"==================================\n");
}
GUI class:
package javaapplication2;
import java.awt.event.ActionEvent;
import java.io.PrintStream;
import java.util.Scanner;
/*
* 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.
*/
/**
*
* #author viljo
*/
public class TrainingProgrammeGUI extends javax.swing.JFrame {
static PrintStream printStream = new PrintStream(new GUITextOutputStream(TrainingProgrammeGUI.jTextArea1));
double startTimer = System.nanoTime();
double stopTimer = 0;
Scanner scan = new Scanner(System.in);
Player gameCharacter = null;
Teacher teacher = null;
int finishedProgram = 0;
int userChoice = -1;
/**
* Creates new form TrainingProgrammeGUI
*/
public TrainingProgrammeGUI() {
initComponents();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
filler1 = new javax.swing.Box.Filler(new java.awt.Dimension(0, 0), new java.awt.Dimension(0, 0), new java.awt.Dimension(32767, 32767));
jLabel1 = new javax.swing.JLabel();
jScrollPane1 = new javax.swing.JScrollPane();
jTextArea1 = new javax.swing.JTextArea();
jTextField1 = new javax.swing.JTextField();
jLabel2 = new javax.swing.JLabel();
jButton1 = new javax.swing.JButton();
jButton3 = new javax.swing.JButton();
jLabel3 = new javax.swing.JLabel();
jButton4 = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel1.setFont(new java.awt.Font("Arial", 1, 24)); // NOI18N
jLabel1.setText("CIA Training Programme");
jTextArea1.setColumns(20);
jTextArea1.setRows(5);
jScrollPane1.setViewportView(jTextArea1);
jTextField1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jTextField1ActionPerformed(evt);
}
});
jLabel2.setFont(new java.awt.Font("Tahoma", 1, 11)); // NOI18N
jLabel2.setText("Game: ");
jButton1.setText("Start Game");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jButton3.setText("What is this game?");
jButton3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton3ActionPerformed(evt);
}
});
jLabel3.setFont(new java.awt.Font("Tahoma", 1, 11)); // NOI18N
jLabel3.setText("Type Here: ");
jButton4.setText("Exit");
jButton4.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton4ActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(filler1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(159, 159, 159))
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(261, 261, 261)
.addComponent(jLabel1))
.addGroup(layout.createSequentialGroup()
.addGap(94, 94, 94)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jLabel2)
.addComponent(jLabel3))
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 456, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 131, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGroup(layout.createSequentialGroup()
.addGap(170, 170, 170)
.addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 132, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(33, 33, 33)
.addComponent(jButton3, javax.swing.GroupLayout.PREFERRED_SIZE, 132, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(33, 33, 33)
.addComponent(jButton4, javax.swing.GroupLayout.PREFERRED_SIZE, 132, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(175, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel1)
.addGap(70, 70, 70)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 47, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton3, javax.swing.GroupLayout.PREFERRED_SIZE, 47, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton4, javax.swing.GroupLayout.PREFERRED_SIZE, 45, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 60, Short.MAX_VALUE)
.addComponent(filler1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel3))
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 226, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel2))
.addGap(20, 20, 20))
);
pack();
}// </editor-fold>
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
TrainingProgrammeGUI programme = new TrainingProgrammeGUI();
programme.setVisible(true);
}
private void jTextField1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {
System.out.print("\nThank you for using our training programme!");
System.exit(0);
}
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
System.out.println("sdsdsdsdsa");
System.setOut(printStream);
System.setErr(printStream);
System.out.println("==================================\n"+
"* WELCOME TO CATCH ME IF YOU CAN *\n"+
"==================================\n");
userChoice = TrainingProgramme.checkInputWithPhrase("1.) Start Game\n2.) What is this game?\n3.) Quit", 1, 3);
teacher = new Teacher("John Doe", "Teacher");
gameCharacter = teacher.introductionLines(); // teacher reads a few lines and asks questions then returns Player class
boolean userFinished = false;
gameCharacter.getHotelRoom().setPlayerHere(true);
do { // Checks which room player is in then reads instructions for room. Loop finishes when player wants to chooses suspect
if (gameCharacter.getHotelKitchen().isPlayerHere()) {
if ("HotelRoom".equals((gameCharacter.getHotelKitchen().instructions(teacher)))) {
System.out.println("\nRoom chosen!\n");
gameCharacter.getHotelKitchen().setPlayerHere(false); // Takes player out of current room
gameCharacter.getHotelRoom().setPlayerHere(true); // Puts players into chosen room
}
} else {
if ("Choose".equals((gameCharacter.getHotelRoom().instructions(teacher)))) {
stopTimer = System.nanoTime();
Player.timeTaken = (stopTimer - startTimer) / 10000000; //time taken to finish inspecting items (in seconds)
teacher.chooseWhoDidIt(gameCharacter);
finishedProgram = 1; //Stop the curret loop
userFinished = true; //Stop the main menu loop
} else {
System.out.println("\nKitchen chosen!\n");
gameCharacter.getHotelRoom().setPlayerHere(false);// Takes player out of current room
gameCharacter.getHotelKitchen().setPlayerHere(true);// Puts players into chosen room
}
}
} while (userFinished == false);
}
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
System.out.println("\n+===========================================================+");
System.out.println("|This game was created to help train our new junior recruits|");
System.out.println("+===========================================================+\n\n");
System.out.println("Objective: Gather evidence by looking for clues\n"+
"and once you are done go back to the room to guess \n"+
"which suspect did it. Suspects are provided once you have\n"+
"went back to the room and decided to guess who did the crime!\n");
}
// Variables declaration - do not modify
private javax.swing.Box.Filler filler1;
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton3;
private javax.swing.JButton jButton4;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JScrollPane jScrollPane1;
public static javax.swing.JTextArea jTextArea1;
private javax.swing.JTextField jTextField1;
// End of variables declaration
}
PrintStream class:
package net.codejava.swing;
import java.io.IOException;
import java.io.OutputStream;
import javax.swing.JTextArea;
/**
* This class extends from OutputStream to redirect output to a JTextArrea
* #author www.codejava.net
*
*/
public class CustomOutputStream extends OutputStream {
private JTextArea textArea;
public CustomOutputStream(JTextArea textArea) {
this.textArea = textArea;
}
#Override
public void write(int b) throws IOException {
// redirects data to the text area
textArea.append(String.valueOf((char)b));
// scrolls the text area to the end of data
textArea.setCaretPosition(textArea.getDocument().getLength());
}
}

How do I make a program that I have already created run after I press a button in a different program that I have made?

I'm doing a project where I need 4 buttons and each button will perform a different mathematical function of some sort. I have all of the functions written in programs separate from the program with the buttons.
I'm going to just use a sample program that I made in NetBeans instead of posting the whole code on my actual project.
public class NewJPanel extends javax.swing.JPanel {
/**
* Creates new form NewJPanel
*/
public NewJPanel() {
initComponents();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jTextField1 = new javax.swing.JTextField();
jButton1 = new javax.swing.JButton();
jButton2 = new javax.swing.JButton();
jButton3 = new javax.swing.JButton();
jTextField1.setText("jTextField1");
jButton1.setText("jButton1");
jButton2.setText("jButton2");
jButton3.setText("jButton3");
jButton3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton3ActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
this.setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(27, 27, 27)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jButton1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton3))
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap(79, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(29, 29, 29)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 149, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton1)
.addComponent(jButton2)
.addComponent(jButton3))
.addGap(78, 78, 78))
);
}// </editor-fold>
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JButton jButton3;
private javax.swing.JTextField jTextField1;
// End of variables declaration
}
So that is the program with the buttons. Now how would I execute a program called Celsius after pressing one of the JButtons?

You must not reason in terms of programs starting other programs, but in terms of classes using other classes.
So let's say your Celsius program has a Celsius class with the method
int convertToFahrenheit(int celsiusDegrees)
Your program will make sure to have the jar file of the celsius program, containing the Celsius class, in its classpath, and will simply use, when a button is clicked
Celsius celsius = new Celsius();
int fahrenheit = celsius.convertToFehrenheit(someCelsiusDegrees);
So, to be short, the celsius program will become a library used by your new Swing program.

import java.io.*;
public class CallHelloPgm
{
public static void main(String args[])
{
Process theProcess = null;
BufferedReader inStream = null;
// call the Hello class
try
{
theProcess = Runtime.getRuntime().exec("java someProgram"); // Your magic line
}
catch(IOException e)
{
System.err.println("Error on exec() method");
e.printStackTrace();
}
// read from the called program's standard output stream
try
{
inStream = new BufferedReader(
new InputStreamReader( theProcess.getInputStream() ));
System.out.println(inStream.readLine());
}
catch(IOException e)
{
System.err.println("Error on inStream.readLine()");
e.printStackTrace();
}
} // end method
} // end class

Java, select text Exactly in JEditorPane

I'm using jEditorPane to act kinda as some editor, the one who asked for this of me, also needed a find replace search... so I wanted to let him select in find and then do replace on need.
so I provide this simple code:
private void jButton5ActionPerformed(java.awt.event.ActionEvent evt) {
int start = (jEditorPane1.getSelectionStart()>jEditorPane1.getSelectionEnd())?jEditorPane1.getSelectionEnd():jEditorPane1.getSelectionStart();
int max = (start>jEditorPane1.getSelectionStart())?start:jEditorPane1.getSelectionStart();
String searchWord = jTextField3.getText();
int searchIndex = jEditorPane1.getText().indexOf(searchWord, max);
if(searchIndex != -1){
jEditorPane1.select(searchIndex, searchIndex+searchWord.length());
}
else{
jEditorPane1.setSelectionStart(-1);
jEditorPane1.setSelectionEnd(-1);
}
}
fortunatelly the application return good indexes, but unfortunatelly on view windows I see no selection.
I'm also new to java, please help
PS. buttons action are provided by netbeans itself
THe sample you requested
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
/*
* test.java
*
* Created on Jun 12, 2013, 8:23:19 PM
*/
package wordchecker;
/**
*
* #author Hassan
*/
public class test extends javax.swing.JFrame {
/** Creates new form test */
public test() {
initComponents();
}
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jScrollPane1 = new javax.swing.JScrollPane();
jTextPane1 = new javax.swing.JTextPane();
jTextField1 = new javax.swing.JTextField();
jButton1 = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jScrollPane1.setViewportView(jTextPane1);
jTextField1.setText("jTextField1");
jButton1.setText("jButton1");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(24, 24, 24)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jButton1))
.addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 366, Short.MAX_VALUE))
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 234, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton1))
.addContainerGap(14, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
int startFrom = jTextPane1.getSelectionStart();
if(jTextPane1.getSelectionStart() == jTextPane1.getSelectionEnd()){
startFrom = -1;
}
String searchWord = jTextField1.getText();
int searchIndex = jTextPane1.getText().indexOf(searchWord, startFrom);
if(searchIndex != -1){
jTextPane1.select(searchIndex, searchIndex+searchWord.length());
}
else{
jTextPane1.setSelectionStart(0);
jTextPane1.setSelectionEnd(0);
}
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new test().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTextField jTextField1;
private javax.swing.JTextPane jTextPane1;
// End of variables declaration
}

The selection of a text component is only displayed when the text component has focus. When you click on the button it gains focus so you don't see the text selection. You could make the button non-focusable or you can add the following to the bottom of your actionPerformed() method:
jTextPane1.requestFocusInWindow();
Also, don't use the getText() method. This will cause problems with offsets.
int searchIndex = jTextPane1.getText().indexOf(searchWord, startFrom);
See Text and New Lines for more information and a solution. The basics of this link is to use:
int length = textPane.getDocument().getLength();
String text = textPane.getDocument().getText(0, length);
The above will only return "\n" as the EOL string so the offsets will match when you do a search and then select the text.
Edit:
I generally use code like the following:
int startFrom = jTextPane1.getCaretPosition();

How can I read a wav file and replace bits in it?

I've just started learning Java and I'm working on an audio steganography project in Java (i.e. hiding a text file in a wav file).
For that I store a text and wav file in two files. Now I want to read them in bytes and replace random bits of the wav file with text file bits.
How can i read the files in bytes? (I've tried using InputStream). Is it possible to replace random bits in wav file with bits of text file? Are there any functions for it?
Once I've read the files (both text and wav file), how can I edit (and replace) the bytes of wav file?
This is the the First screen, when user hits on HIDE button, the next screen opens up.
public class OptionScreen extends javax.swing.JFrame {
/** Creates new form OptionScreen */
public OptionScreen() {
initComponents();
}
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
hide = new javax.swing.JButton();
unhide = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
hide.setText("Hide");
hide.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
hideActionPerformed(evt);
}
});
unhide.setText("UnHide");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(55, 55, 55)
.addComponent(hide, javax.swing.GroupLayout.PREFERRED_SIZE, 88, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(94, 94, 94)
.addComponent(unhide, javax.swing.GroupLayout.PREFERRED_SIZE, 82, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(81, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(109, 109, 109)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(hide, javax.swing.GroupLayout.PREFERRED_SIZE, 88, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(unhide, javax.swing.GroupLayout.PREFERRED_SIZE, 90, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap(101, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void hideActionPerformed(java.awt.event.ActionEvent evt) {
second s=new second();
s.setVisible(true);
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new OptionScreen().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton hide;
private javax.swing.JButton unhide;
// End of variables declaration
}
import java.io.DataInputStream;
import java.io.File;
import java.io.File.*;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JFileChooser;
public class second extends javax.swing.JFrame {
private File afile; // put at bottom of class
private File tfile;
/** Creates new form second */
public second() {
initComponents();
}
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
text = new javax.swing.JButton();
audio = new javax.swing.JButton();
tname = new javax.swing.JLabel();
aname = new javax.swing.JLabel();
begin = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
text.setText("TEXT FILE");
text.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
textActionPerformed(evt);
}
});
audio.setText("AUDIO FILE");
audio.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
audioActionPerformed(evt);
}
});
begin.setFont(new java.awt.Font("Tahoma", 1, 11)); // NOI18N
begin.setText("BEGIN");
begin.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
beginActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(87, 87, 87)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addComponent(text, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(audio, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addGroup(layout.createSequentialGroup()
.addGap(18, 18, 18)
.addComponent(tname, javax.swing.GroupLayout.PREFERRED_SIZE, 57, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(26, 26, 26)
.addComponent(aname, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))))
.addGroup(layout.createSequentialGroup()
.addGap(270, 270, 270)
.addComponent(begin, javax.swing.GroupLayout.PREFERRED_SIZE, 99, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(31, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(101, 101, 101)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(text)
.addComponent(tname, javax.swing.GroupLayout.PREFERRED_SIZE, 19, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(32, 32, 32)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(audio)
.addComponent(aname, javax.swing.GroupLayout.PREFERRED_SIZE, 19, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(begin, javax.swing.GroupLayout.PREFERRED_SIZE, 96, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(19, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void textActionPerformed(java.awt.event.ActionEvent evt) {
JFileChooser opentext=new JFileChooser();
opentext.showOpenDialog(this);
int returnVal = opentext.showOpenDialog(this);
if (returnVal == JFileChooser.APPROVE_OPTION) {
tfile = opentext.getSelectedFile();
String tfname=tfile.getName();
tname.setText(tfname);
// ... code that loads the contents of the file in the text area
}
}
private void audioActionPerformed(java.awt.event.ActionEvent evt) {
JFileChooser openaudio=new JFileChooser();
openaudio.showOpenDialog(this);
int returnVal = openaudio.showOpenDialog(this);
if (returnVal == JFileChooser.APPROVE_OPTION) {
afile = openaudio.getSelectedFile();
aname.setText(afile.getName());
// ... code that loads the contents of the file in the text area
}
}
private void beginActionPerformed(java.awt.event.ActionEvent evt) {
try {
InputStream fint = new FileInputStream(tfile);
byte []bt=new byte[(int)afile.length()];
InputStream fina = new FileInputStream(afile);
int offset = 0;
int numRead = 0;
//
try {
System.out.println(new DataInputStream(fint).readByte());
} catch (IOException ex) {
Logger.getLogger(second.class.getName()).log(Level.SEVERE, null, ex);
}
//
System.out.println(bt);
//////////////////////////////////////////////////////////////////
FileOutputStream outs=new FileOutputStream(new File("C:\\Documents and Settings\\Administrator\\My Documents\\My Music\\Secret.wav"));
} catch (FileNotFoundException ex) {
}
//end of try catch
}
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new second().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JLabel aname;
private javax.swing.JButton audio;
private javax.swing.JButton begin;
private javax.swing.JButton text;
private javax.swing.JLabel tname;
// End of variables declaration
}

You have 2 ways: (1) read your file into byte array, than manipulate it in memory and then write it back to disk. (2) use RandomAccessFile that allows you manipulating file directly on disk.

Cannot display image on Jpanel

I'm using the Netbeans GUI builder, but it's a little confusing now. How can I add an image to a panel? I think i'm doing it correct, but it's not showing up. I think it should be in the init() method, but netbeans does not allow me to change that part of the code. This is the code I added for the image:
//these four lines I added to add the image
imageIcon = new ImageIcon("login_icon.png");
image = new JLabel(imageIcon);
image.setToolTipText("SGS Security");
topPanel.add(image);
My Class starts here:
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
/*
* Login.java
*
* Created on Oct 27, 2009, 8:34:15 PM
*/
package sgs;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
public class Login extends javax.swing.JFrame {
JLabel image;
ImageIcon imageIcon;
/** Creates new form Login */
public Login() {
initComponents();
//these four lines I added to add the image
imageIcon = new ImageIcon("login_icon.png");
image = new JLabel(imageIcon);
image.setToolTipText("SGS Security");
topPanel.add(image);
}
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
topPanel = new javax.swing.JPanel();
userLabel = new javax.swing.JLabel();
passwordLabel = new javax.swing.JLabel();
connectLabel = new javax.swing.JLabel();
forgotPassLabel = new javax.swing.JLabel();
forgotPassCheckBox = new javax.swing.JCheckBox();
cancelButton = new javax.swing.JButton();
okButton = new javax.swing.JButton();
passwordTextField = new javax.swing.JTextField();
userTextField = new javax.swing.JTextField();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setBackground(new java.awt.Color(216, 156, 60));
topPanel.setBackground(new java.awt.Color(28, 90, 198));
javax.swing.GroupLayout topPanelLayout = new javax.swing.GroupLayout(topPanel);
topPanel.setLayout(topPanelLayout);
topPanelLayout.setHorizontalGroup(
topPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 406, Short.MAX_VALUE)
);
topPanelLayout.setVerticalGroup(
topPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 71, Short.MAX_VALUE)
);
userLabel.setText("User name:");
passwordLabel.setText("Password:");
connectLabel.setText("Connect to SGS");
forgotPassLabel.setText("Forgot password");
forgotPassCheckBox.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
forgotPassCheckBoxActionPerformed(evt);
}
});
cancelButton.setText("Cancel");
okButton.setText("OK");
okButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
okButtonActionPerformed(evt);
}
});
userTextField.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
userTextFieldActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(connectLabel)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(passwordLabel)
.addComponent(userLabel)))
.addGap(30, 30, 30)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(userTextField)
.addComponent(passwordTextField)
.addGroup(layout.createSequentialGroup()
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(forgotPassCheckBox)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(forgotPassLabel))
.addGroup(layout.createSequentialGroup()
.addGap(32, 32, 32)
.addComponent(okButton, javax.swing.GroupLayout.PREFERRED_SIZE, 101, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(28, 28, 28)
.addComponent(cancelButton, javax.swing.GroupLayout.PREFERRED_SIZE, 101, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap())
.addComponent(topPanel, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(topPanel, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(27, 27, 27)
.addComponent(connectLabel)
.addGap(34, 34, 34)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(userLabel)
.addComponent(userTextField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(passwordLabel)
.addComponent(passwordTextField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(forgotPassLabel)
.addComponent(forgotPassCheckBox))
.addGap(23, 23, 23)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(okButton, javax.swing.GroupLayout.PREFERRED_SIZE, 31, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(cancelButton, javax.swing.GroupLayout.DEFAULT_SIZE, 31, Short.MAX_VALUE))
.addContainerGap())
);
pack();
}// </editor-fold>
private void forgotPassCheckBoxActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
private void userTextFieldActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
private void okButtonActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Login().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton cancelButton;
private javax.swing.JLabel connectLabel;
private javax.swing.JCheckBox forgotPassCheckBox;
private javax.swing.JLabel forgotPassLabel;
private javax.swing.JButton okButton;
private javax.swing.JLabel passwordLabel;
private javax.swing.JTextField passwordTextField;
private javax.swing.JPanel topPanel;
private javax.swing.JLabel userLabel;
private javax.swing.JTextField userTextField;
// End of variables declaration
}

Ditch the GUI builder and learn how to create GUIs on your own. That way you spend time learning Java instead of learning an IDE. There is probably some GroupLayout property that is not properly set and since GroupLayout was designed to be used by IDEs and not humans I have no idea what the problem might be.
The other possibility is that the IDE can't find your image. Did you add a System.out.println to diplay the image and make sure its not null.
I suggest you read the section from the Swing tutorial on How to Use Icons for a working example that you can download and test to see if it works. Just replace the icons in the tutorial with your icons to make sure they are found.
Edit:
After having a second look at the code I believe my original suggestion is correct. You attempt to add the label to the panel using a single line of code:
topPanel.add(image);
Look at the code generated by the IDE. The add statements are NOT that simple. If you want to manually add a component after the fact then you need read the section from the tutorial on "How to Use Group Layout" to understand the various constraints and methods used.
Or you need to figure out how to do it in the IDE. Thats why I prefer the do it yourself approach. Then you are responsible for the code, not the IDE.

This is one of the weird behaviors in Java (GUIs). You can manually paint the image on a panel.
Here is what I use:
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2= (Graphics2D) g;
if (currentImage != null) {
g2.drawImage(currentImage, null, 0, 0);
}
}
Also you should create a "ImagePanel" component, which is an JPanel that encapsolates the Image.
The middle arguement for drawImage is null, because I do not intend on performing an image operation on it.