Develop Reference

how can import ms.security package

I am beginner in java.
I want run native application from applet.
I found Run App In Every Browser
Java Code
import com.ms.security.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.io.* ;
import java.util.*;
import netscape.security.PrivilegeManager;
public class RunApp extends Applet implements ActionListener {
TextArea ta = new TextArea (25, 80);
Button startbutton = new Button("Start Application") ;
private static String execommand = "C:\\windows\\notepad.exe" ;
private String osname;
public void init() {
try {
if (Class.forName("com.ms.security.PolicyEngine") != null) { // required for IE
PolicyEngine.assertPermission(PermissionID.SYSTEM);
}
}
catch (Throwable cnfe) {
}
this.setBackground(Color.white) ;
startbutton.addActionListener(this) ;
add(startbutton) ;
startbutton.setBackground(Color.red) ;
try{
PrivilegeManager.enablePrivilege("UniversalExecAccess") ; // required for NN
}
catch(Exception cnfe) {
System.out.println("netscape.security.PrivilegeManager class not found") ;
}
osname = System.getProperty("os.name"); // if NT, Win2000 or WinXP, adjust path
if(osname.equals("Windows NT") || osname.equals("Windows 2000")|| osname.equals("Windows XP"))
execommand = "C:\\winnt\\notepad.exe" ;
}
public void actionPerformed(ActionEvent e) {
if( (e.getActionCommand()).equals("Start Application")) {
try{
PrivilegeManager.enablePrivilege("UniversalExecAccess") ; // required for NN
}
catch(Exception cnfe) {
System.out.println("netscape.security.PrivilegeManager class not found") ;
}
try {
Process proc = Runtime.getRuntime().exec(execommand) ;
}
catch(IOException ieo) {
System.out.println("Problem starting " + execommand) ;
}
// System.out.println("execommand: " + execommand) ;
}
}
}
But when run it say error:package com.ms.security does not exit!
I does not any folder with ms or security name .
I should create folder with ms and then security in root file or should import library ms.security .
where is com.ms.security or netscape.security.PrivilegeManager?
how can download it?i search for download this package but i does not found anythings
I use eclipse for write code.

This package does not exist any more. The tutorial you point to dates from 2002. You can look at this javaranch post: http://www.coderanch.com/t/375470/java/java/Location-Jar-ms-security, and at the Microsoft documentation (https://msdn.microsoft.com/en-us/library/aa242534(v=vs.60).aspx). So basically your code would have worked 13 years ago, but with Microsoft not supporting their own JVM any more it's obsolete. Sorry!

You need to download that jar having this package ,com.ms.security. And b4 compiling your java class set that jar in your classpath from command prompt.
set classpath=%classpath%;path_of_your_jar;

This package is not existed anymore. Microsoft is not supporting their own JVM anymore. You should try to learn java applet in the new way, such as http://www.tutorialspoint.com/java/java_applet_basics.htm.

The import statement import com.ms.security.*; requires you to have a folder com, with a subfolder ms, with a subfolder security, which contains the needed files.
I think you are missing some files for your application.
I recommend reading this post, for the use of imports: https://stackoverflow.com/a/12620773/3234981

Please check your jar file which contain the respective package are present in the classpath or not. If not, push them to classpath and re-compile the same class on a new command line.
Happy Learning.

Java program runs fine in Eclipse but not as a .jar file

I've got an issue with my .jar file. It runs fine in Eclipse but as soon as I export it, it won't open. I've checked the manifest file and it looks like it's okay.
I've tried exporting it as a runnable jar, as well as just using the jar builder. Nothing worked.
I've tried to run it in command prompt and it says it can't access the jar file... I've searched around a while on here and haven't found an answer yet.
I'm not sure what I'm doing wrong. The only thing I can think of is I'm not getting my images correctly.
I'm using .png files for the program's sprites and here's an example of how I get them for my program.
This code begins the building of a level from a .png file.
public class SpawnLevel extends Level{
public SpawnLevel(String path) {
super(path);
}
protected void loadLevel(String path){
try{
System.out.println("classpath is: " + System.getProperty("java.class.path"));
BufferedImage image = ImageIO.read(SpawnLevel.class.getResource(path));
int w = width = image.getWidth();
int h = height= image.getHeight();
tiles = new int[w*h];
image.getRGB(0,0,w,h,tiles,0,w);
}catch(IOException e){
e.printStackTrace();
System.out.println("EXEPTION FOUND!!! Could not load the level file!");
}
}
protected void generateLevel(){
System.out.println("Tiles: " + tiles[0]);
}
}
I've made one other .jar before for another program and didn't have a problem. Any help would be greatly appreciated.
If it helps, I used this code to display the resource folder path information.
System.out.println("classpath is: " + System.getProperty("java.class.path"));
Here's what my current path for my resources folder looks like. Before I export it from eclipse.
classpath is: C:\Users\name\workspace\Rpg_Game\bin;C:\Users\name\workspace\Rpg_Game\res
After I export to .jar
classpath is: 2ndGameTest.jar

If your images are in your resources package in the src The path you should be using for getResource() is something like
class.getResource("/resources/levels/level1.png")
UPDATE with test program
import java.awt.Image;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
public class TestImage {
public static void main(String[] args) throws IOException {
Image image = ImageIO.read(TestImage.class.getResource("/resources/images/image.png"));
ImageIcon icon = new ImageIcon(image);
JLabel label = new JLabel(icon);
JOptionPane.showMessageDialog(null, label);
}
}

Java applet can't find resources in jar if run locally

Problem: Java applet can't load resources located inside its jar when run locally on windows platforms. The same applet can load the resources if it is launched from a web server instead of launched locally or if it's launched locally on a linux system. In all cases the applet is launched using an applet tag.
Steps to reproduce
1) Build applet class code below and create a jar containing the following:
TestApplet.class
iconimg.png
test.html
META-INF folder (standard manifest with one line: "Manifest-Version: 1.0")
Here's a link to the image png file I used:
http://flexibleretirementplanner.com/java/java-test/iconimg.png
The file test.html has one line:
<h1>Text from test.html file</h1>
2) create launch.html in same folder as test.jar as follows:
<html><center><title>Test Applet</title><applet
archive = "test.jar"
code = "TestApplet.class"
name = "Test Applet"
width = "250"
height = "150"
hspace = "0"
vspace = "0"
align = "middle"
mayscript = "true"
></applet></center></html>
3) With test.jar in the same local folder as launch.html, click on launch.html
4) Notice that getResource() calls for imgicon.png and test.html both return null.
5) Upload launch.html and test.jar to a web server and load launch.html and notice that the resources are found.
TestApplet.java
import java.applet.AppletContext;
import java.io.IOException;
import java.net.URL;
import javax.swing.ImageIcon;
import javax.swing.JApplet;
import javax.swing.JEditorPane;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class TestApplet extends JApplet {
public TestApplet() {
try {
jbInit();
} catch (Exception ex) {
ex.printStackTrace();
}
}
public void init() {
JPanel topPanel = new JPanel();
JLabel iconLabel;
URL url = TestApplet.class.getClassLoader().getResource("iconimg.png");
if (url != null)
iconLabel = new JLabel(new ImageIcon(url));
else
iconLabel = new JLabel("getResource(iconimg.png)==null");
topPanel.add(iconLabel);
URL url2;
url2 = TestApplet.class.getClassLoader().getResource("test.html");
if (url2 == null) {
JLabel errorLabel = new JLabel("getResource(test.html) == null");
topPanel.add(errorLabel);
} else {
try {
JEditorPane htmlPane = new JEditorPane(url2);
topPanel.add(htmlPane);
} catch (IOException ioe) {
System.err.println("Error displaying " + url2);
}
}
getContentPane().add(topPanel);
}
private void jbInit() throws Exception { }
}

Oracle has decided to modify the behavior of getDocumentBase(), getCodeBase() and getResource() because security reasons since 1.7.0_25 on Windows: http://www.duckware.com/tech/java-security-clusterfuck.html
It seems there is a lot of discussion about this change because it breaks some important valid and secure use cases.

After further research and discovering that this is a windows-only problem, I'm calling this one answered.
It's almost certainly a java 1.7.0.25 bug. The applet runs fine from a web server and also runs fine locally on a virtual Ubuntu system (using VirtualBox on windows). Hopefully the bug report i submitted will be helpful to the java folks.
Thanks for the responses. Btw, it was Joop's comment about case sensitivity that spurred me to test a linux system just for kicks. Thanks for that!

How to play a background music when the program run? in java

I am making a card game, and it's almost done. The last thing I want to do is play some background music. Now if I copy the file into the default package and make a single jar file of the game, will the music play on all computers? Currently, on my PC it's running without any problem by giving a specific path for the file like "C:\\samp.wav";. But I am worried that if I make a jar file and run it on another PC it won't work properly. I think there will be a FileNotFoundException. Am I right or wrong?
For the card's image I am using this line:
jLabel1.setIcon(new javax.swing.ImageIcon(getClass().getResource("/1.jpg")));
Those pictures I have inserted into my default package. I want to do the same for the music file, but how? I am using NetBeans.

You should include the wav file inside your application jar. This way you won't have to manage the copy of the file in the user's file system (keep in mind that, for example, in UNIX, Mac, etc. you can't access to the hard drive through C:/...).
For example, if you place the wav file in the root of the app jar (app.jar/samp.wav):
InputStream is = getClass().getClassLoader().getResourceAsStream("samp.wav");
or, if you had a "sounds" directory in the app jar root (app.jar/sounds/samp.wav):
InputStream is = getClass().getClassLoader().getResourceAsStream("sounds/samp.wav");
Check this post for extra information about playing wav files with Java (though for your question, I think you have already solved this problem). Consider as well playing it in a separate thread. Check also this web for examples about managing media files in Java.

import javax.swing.*;
import sun.audio.*;
import java.awt.event.*;
import java.io.*;
public class Sound {
public static void main(String[] args)
{
JFrame frame = new JFrame();
frame.setSize(200,200);
JButton button = new JButton("Click me");
frame.add(button);
button.addActionListener(new AL());
frame.setVisible(true);
}
public static class AL implements ActionListener{
public final void actionPerformed(ActionEvent e){
music();
}
}
public static void music(){
AudioPlayer MGP = AudioPlayer.player;
AudioStream BGM;
AudioData MD;
ContinuousAudioDataStream loop = null;
try{
BGM = new AudioStream(new FileInputStream("C:\\test\\ha.wav"));
MD = BGM.getData();
loop = new ContinuousAudioDataStream(MD);
}catch(IOException error){
System.out.print("file not found");
}
MGP.start(loop);
}
}

How to run the Linux "cd" command from Java?

I want to write a Java program to delete ~12 directories or files which are under my home directory. I am able to do this by using
Process proc = Runtime.getRuntime().exec("rm -rf *path*")
But I have to run this command 12 times or I can keep it in loop. What I really want is to have a file in my home directory that contains the names of all the directories and files to delete in it. My Java program should go to the home directory, read the file, and delete all the specified files.
I am stuck at the very first step – I am not able to cd to the home directory. Please let me know how can I achieve this.
Thanks for all of your replies.
But, here I don't really want to use the Java util classes rather I want to learn a way using which I can run Linux commands in my Java class. Being a deployment Intern, I have to reset the environment every time before deploying a new environment for the customer. For this, I repeatedly use some basic Linux commands. I can write a shell script to do this but for this time, I want to write a Java class in which I can put all these Linux commands and run from one class.
The commands which I use are:
kill all java processes which are started by the admin ONLY – for this I need to use multiple Linux commands with “pipe”
Remove all 12-directories/files from home directory
stop some services (like siebel, etc.) – for this I need to go under the particular directories and run ./shutdown.sh or ./stop_ns, etc.
run some database scripts – to reset the database schemas
again start the services – same as step 2 except this time I need to run ./start_ns, etc.
I really appreciate if you can let me know
a. How can I navigate into a directory using Java code
b. How can I run multiple Linux commands using pipe using Java code

Why do you need to "go" to the home directory? Just read the file wherever you are:
String homeDirectory = System.getProperty("user.home");
File file = new File(homeDirectory, "filenames.txt"); // Or whatever
// Now load the file using "file" in the constructor call to FileInputStream etc
It's very rarely a good idea to require that a process changes working directory just to do the right thing.

You dont need to change directory. You can just read file using absolute path using FileReader(String fileName).

For deleting entire directories, try Apache Commons IO's class FileUtils:
FileUtils.deleteDirectory(new File(System.getProperty("user.home")));
Or use cleanDirectory to delete everything in home but not home itself:
FileUtils.cleanDirectory(new File(System.getProperty("user.home")));
If you want to delete specific files only (e.g. those matching a name pattern), list the files first, then delete them:
File startDir = new File(System.getProperty("user.home"));
//this should return the leaf files first, then the inner nodes of the directory tree
Collection<File> files = FileUtils.listFiles(startDir , someFileFiler, someDirFilter);
for(File f : files) {
f.delete();
}

"cd" is a shell internal command, not a executable program.
Even you can change dir in java program by whatever means like JNA, when it exit, the current dir in shell is not changed, because the java program runs in another process than the shell.
But we still can do something about it.
eg. I want to make a new shell command called xcd, it popup a GUI shows a list let you select directories existed in bash history, and change current dir to it for you.
in ~/.bashrc add a line:
xcd(){
XCDRES=`xcd.sh`
if [ "$XCDRES" ]; then
cd "$XCDRES"
fi
}
2.xcd.sh is
#!/bin/bash
java -cp $PATH1/xcd.jar neoe.xcd.Main
and add xcd.sh to PATH
the java program is
package neoe.xcd;
import java.awt.Toolkit;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.StringSelection;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import javax.swing.JComponent;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.ListSelectionModel;
public class Main {
public static String getUserHomeDir() {
return System.getProperty("user.home");
}
public static void main(String[] args) throws Exception {
new Main().run();
}
public static String readString(InputStream ins, String enc) throws IOException {
if (enc == null)
enc = "UTF-8";
BufferedReader in = new BufferedReader(new InputStreamReader(ins, enc));
char[] buf = new char[1000];
int len;
StringBuffer sb = new StringBuffer();
while ((len = in.read(buf)) > 0) {
sb.append(buf, 0, len);
}
in.close();
return sb.toString();
}
private String[] selection = new String[1];
private void run() throws Exception {
File hisfile = new File(getUserHomeDir(), ".bash_history");
if (!hisfile.exists()) {
System.err.println(".bash_history not exists, quit");
return;
}
String[] ss = readString(new FileInputStream(hisfile), null).split("\n");
List<String> res = new ArrayList<String>();
Set uniq = new HashSet();
for (String s : ss) {
s = s.trim();
if (!s.startsWith("cd /")) {
continue;
}
s = s.substring(3);
File f = new File(s);
if (f.isDirectory()) {
s = f.getAbsolutePath();
if (uniq.contains(s)) {
continue;
}
uniq.add(s);
res.add(s);
}
}
if (res.isEmpty()) {
System.err.println("no cd entry, quit");
return;
}
Collections.sort(res);
String cd1 = selectFromList(res);
if (cd1 == null) {
System.err.println("not selected, quit");
return;
}
doCd(cd1);
}
private void doCd(String cd1) throws Exception {
System.out.println(cd1);
}
private String selectFromList(List<String> res) {
final JList list = new JList(res.toArray());
list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
final JDialog frame = wrapFrame(new JScrollPane(list), "select dir to cd");
list.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
if (e.getClickCount() > 1) {
String s = (String) list.getSelectedValue();
selection[0] = s;
frame.dispose();
}
}
});
list.addKeyListener(new KeyAdapter() {
#Override
public void keyPressed(KeyEvent e) {
int kc = e.getKeyCode();
if (kc == KeyEvent.VK_ESCAPE) {
frame.dispose();
} else if (kc == KeyEvent.VK_ENTER) {
String s = (String) list.getSelectedValue();
selection[0] = s;
frame.dispose();
}
}
});
frame.setVisible(true);
frame.requestFocus();
return selection[0];
}
private JDialog wrapFrame(JComponent comp, String title) {
JDialog frame = new JDialog();
frame.setTitle("select dir to cd");
frame.setModal(true);
frame.add(comp);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setSize(400, 600);
frame.setLocationRelativeTo(null);
return frame;
}
}
use xcd in shell.

You can't really do that. Java programs don't really allow you to change the "current working directory" as most people understand it (not without using native code, anyway). The normal Java approach is to open a File instance on the directory you want to manipulate, and then use operations on that instance to manipulate the files/directories in question.
For details on how to delete directories programatically in Java, see: Delete directories recursively in Java