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rt.jar / Key.Adapter.class

Googling a lot, I found nothing about the problem with this specific class (Key.Adapter.class), but there are a lot of topics about rt.jar of course, and I tried so many things to correct it, I tried to set the location of rt.jar and installed the plugin Java Source Attacher (didn't work). I reinstalled Eclipse as well, but the error still occurs:
What's strange about this is that I didn't make any change at anything related to the library (if I did, that was not intentional). I was just moving some things but nothing related to the libraries. The console returns NullPointerException at line 190:
name2.addKeyListener(new KeyAdapter() {
#Override
public void keyPressed(KeyEvent arg0) {
int key = arg0.getKeyCode();
if (key == KeyEvent.VK_ESCAPE) {
//Custom button text
Object[] options = {"Sim",
"Não"};
int choice = JOptionPane.showOptionDialog(frame1,
"Deseja sair do jogo?",
"Mensagem",
JOptionPane.YES_NO_CANCEL_OPTION,
JOptionPane.QUESTION_MESSAGE,
null,
options,
options[1]);
if (choice == 0) {
System.exit(0);
}
}
}
}
);
To make a new project will be that way as well. And the Window Designer / Run doesn't work as well.
Is there another possibility to make rt.jar useful again?
java.lang.NullPointerException
at view.Main.<init>(Main.java:191)
at view.Main$1.run(Main.java:49)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

Problems with NumberFormatException

I have noticed a strange problem with my program that I just can not figure out. I have included the method that has been flagged up, and the Error that was given. What's confusing me is that I have duplicated this method about 40 times on other buttons, changing only the 'engtf4' to another source where needed. They work perfectly with no errors, yet are written exactly the same. Adding further confusion, the method is executed exactly as intended(even though the error message below is given)?
I have looked around the net for similar problems using keywords - java.lang.NumberFormatException: For input string: "", I did however notice that all the example sites I saw had reference to a particular value in qoute marks. For example, -java.lang.NumberFormatException: For input string: "2345". I would appreciate any help I could get, thanks.
METHOD SOURCE CODE:
if (a.getSource() == engBuy4){
getItems();
q = engtf4.getText();
qq = Long.parseLong(q); //////////// LINE 13086
if (qq > 1000000 || total > 1000000){
Error.setText("You can ship a maximum of 1 million items.");
engtf4.setText("");
}
if (qq <= 1000000 && total <= 1000000){
if (qq > rem){
Error.setText("You can ship " + rem + " more items");
engtf4.setText("");
}
if (qq <= rem){
buyShrEng();
engtf4.setText("");
}
}
ERROR MESSAGE:
Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: ""
at java.lang.NumberFormatException.forInputString(Unknown Source)
at java.lang.Long.parseLong(Unknown Source)
at java.lang.Long.parseLong(Unknown Source)
at DopeWars.DopeWars.mouseReleased(DopeWars.java:13086)
at java.awt.AWTEventMulticaster.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

Long.parseLong() throws a NumberFormatException if the passed string is not a parsable long value. In your case, you are passing an empty string (probably because the user did not enter anything in the input field). You can verify this easily:
...
Long.parseLong("");
...
java.lang.NumberFormatException: For input string: ""
You should always be prepared to catch this exception (besides empty strings, the exception is thrown if the user enters anything which is not a Long), and show an appropriate error message to the user, something like
try {
qq = Long.parseLong(q);
} catch(NumberFormatException nfe) {
// show error message like "The string ... you entered is not a number."
...
}
If you want to treat an empty string as 0 (if that is reasonable for your use case), you can do something like (still requires the try/catch block to catch any other invalid inputs):
try {
long qq = 0;
if (q != null && !q.isEmpty()) {
qq = Long.parseLong(q);
}
...
} catch(NumberFormatException nfe) {
// show error message like "The string ... you entered is not a number."
...
}
In addition to that, instead of duplicating code dozens of times, you should check which are the variable parts of your code and replace them with variables, so that you can reuse the code instead of duplicating it.

It is raising the NumberFormatException, Since the argument passed to the parse() Method, is not parsable. What i mean to say is, input is invalid here.
Checkout the following link :)
http://docs.oracle.com/javase/7/docs/api/java/lang/Long.html

It seems that the value entered is an empty string :java.lang.NumberFormatException: For input string: ""
So before parsing to long you should test if the string value is empty or not.
In any ways you should catch the java.lang.NumberFormatException to put a default value if the parse doesn't succeed

We cannot parse empty space or null to long.If we try that,the number format exception arise.
so before parsing add the if statement to check the value is present or not.
if(q!=null && !"".equals(q))
qq=Long.parse(q);
It's good to use exception handling in these situations

MATLAB reports "Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException"

I wonder about a Java error that is repeatedly occurs in MATLAB. It typically occurs when MATLAB is doing some heavy stuff with Java. This can for example be holding Ctrl + Z or Ctrl + Y.
I did by mistake erase the error message before I copied it, but I think that I can pass the core of the problem anyway.
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
...
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Why did this error occur? I have found some information about this from MATLAB r2007, this due to that Java Swing is thread unsafe and MATLAB lacked support to ensure thread safety. However, that is supposed to have been fixed in MATLAB r2008b. So why do I get it now?
Here is the full stack trace:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at org.netbeans.editor.BaseDocument.notifyUnmodify(BaseDocument.java:1465)
at org.netbeans.editor.BaseDocument.notifyModifyCheckEnd(BaseDocument.java:816)
at org.netbeans.editor.BaseDocumentEvent.redo(BaseDocumentEvent.java:336)
at javax.swing.undo.UndoManager.redoTo(Unknown Source)
at javax.swing.undo.UndoManager.redo(Unknown Source)
at com.mathworks.mwswing.undo.MUndoManager.redo(MUndoManager.java:255)
at org.netbeans.editor.ActionFactory$RedoAction.actionPerformed(ActionFactory.java:767)
at org.netbeans.editor.BaseAction.actionPerformed(BaseAction.java:259)
at javax.swing.SwingUtilities.notifyAction(Unknown Source)
at javax.swing.JComponent.processKeyBinding(Unknown Source)
at javax.swing.JComponent.processKeyBindings(Unknown Source)
at javax.swing.JComponent.processKeyEvent(Unknown Source)
at com.mathworks.widgets.SyntaxTextPaneBase.processKeyEvent(SyntaxTextPaneBase.java:1187)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.KeyboardFocusManager.redispatchEvent(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(Unknown Source)
at java.awt.DefaultKeyboardFocusManager.dispatchEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

Well, based on your stack trace, probably there isn’t any definitive answer to your question, as you have already seen in MATLAB's forum, but given this line, I think there's a possible explanation:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
...
at javax.swing.undo.UndoManager.redoTo(Unknown Source) // <-- here!
at javax.swing.undo.UndoManager.redo(Unknown Source)
at com.mathworks.mwswing.undo.MUndoManager.redo(MUndoManager.java:255)
...
UndoManager class keeps an internal collection of UndoableEdit objects. This collection is actually inherithed from its superclass: CompoundEdit.
The internal implementation of UndoManager#redo() and UndoManager#redoTo(UndoableEdit edit) looks like this:
public class UndoManager extends CompoundEdit implements UndoableEditListener {
...
public synchronized void redo() throws CannotRedoException {
if (inProgress) {
UndoableEdit edit = editToBeRedone();
if (edit == null) {
throw new CannotRedoException();
}
redoTo(edit);
} else {
super.redo();
}
}
...
protected void redoTo(UndoableEdit edit) throws CannotRedoException {
boolean done = false;
while (!done) {
UndoableEdit next = edits.elementAt(indexOfNextAdd++);
next.redo(); // NPE here?
done = next == edit;
}
}
...
}
Considering this implementation and given that Swing's Event Dispatch Thread (EDT) is prone to cause troubles, I think it's probably a threading issue between MATLAB threads and the EDT. Specifically speaking this MATLAB-invoked method could be the source of the problem:
at com.mathworks.mwswing.undo.MUndoManager.redo(MUndoManager.java:255)
Since you say MATLAB needs to do heavy work, it's not unreasonable to think this method is trying to redo some edit that might well not be available anymore or might not be available yet, due to synchronization problems with the EDT.

You can find the ~/.matlab folder which contains MATLAB settings, etc. Use ls -la to show all hidden files and folders.
Open a terminal and execute sudo chmod 757 -R ~/.matlab.
Similarly there is a folder, MATLAB, in Documents.
Execute sudo chmod 757 -R ~/Documents/MATLAB.
Now restart MATLAB without root privileges. It worked for me on Ubuntu 14.04 (Trusty Tahr) and MATLAB 2015a.

What's the difference between http://localhost:8000/ and http://127.0.0.1:8000/ for Java Applets

I have a question/problem related to Java Applet security...
I use the Applet that has to take files from server (ASP.NET) and represent the information from it. Applet take files using the code:
URL u = new URL(getCodeBase(), filename);
BufferedReader d = new BufferedReader(new InputStreamReader(u.openStream()));
This code appears in two places:
Init() method
Some another method Test() that called manually from JavaScript
So, when I try to load the page with Applet using the URL http://127.0.0.1:8000/Test.aspx, everything works fine and I can read file content from both methods. But if I change the URL on http://localhost:8000/, only the first method works properly and I can get files content and for the second one I get the next error message in JavaConsole:
java.security.AccessControlException: access denied (java.net.SocketPermission 127.0.0.1:8000 connect,resolve)
What it the difference in this case? Why 'localhost' is impossible in this case? Is there any way how to grant access to 'localhost' the same as 127.0.0.1?
here is simplest applet's example:
public class TestApplet extends Applet {
public void init()
{
System.out.println( "init...");
readDocument();
}
public void readDocument()
{
System.out.println( "read test.txt file...");
URL base = getCodeBase();
String filename = "test.txt";
try {
URL u = new URL(base, filename);
BufferedReader d = new BufferedReader(new InputStreamReader(u.openStream()));
System.out.println(d.readLine());
System.out.println("Done!");
} catch (Exception e) {
e.printStackTrace();
}
}
}
and next code used on the client side:
<applet archive="/Content/test.jar" code="test.TestApplet.class" name="testApplet" mayscript></applet>
<script language="javascript" type="text/javascript">
$(document).ready(function () {
var testApplet = document.testApplet;
testApplet.readDocument();
});
</script>
this code works perfectly when I try to use http://127.0.0.1:8000/Test.aspx
and doesn't work when I user http://localhost:8000/Test.aspx. I java console I see the next:
init...
read test.txt file...
some text...
Done!
read test.txt file...
java.security.AccessControlException: access denied (java.net.SocketPermission 127.0.0.1:8000 connect,resolve)
at java.security.AccessControlContext.checkPermission(Unknown Source)
at java.security.AccessController.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkConnect(Unknown Source)
at sun.plugin2.applet.Applet2SecurityManager.checkConnect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at sun.net.NetworkClient.doConnect(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.<init>(Unknown Source)
at sun.net.www.http.HttpClient.New(Unknown Source)
at sun.net.www.http.HttpClient.New(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at java.net.URL.openStream(Unknown Source)
at test.TestApplet.readDocument(TestApplet.java:30)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.plugin.javascript.JSInvoke.invoke(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.plugin.javascript.JSClassLoader.invoke(Unknown Source)
at sun.plugin2.liveconnect.JavaClass$MethodInfo.invoke(Unknown Source)
at sun.plugin2.liveconnect.JavaClass$MemberBundle.invoke(Unknown Source)
at sun.plugin2.liveconnect.JavaClass.invoke0(Unknown Source)
at sun.plugin2.liveconnect.JavaClass.invoke(Unknown Source)
at sun.plugin2.main.client.LiveConnectSupport$PerAppletInfo$DefaultInvocationDelegate.invoke(Unknown Source)
at sun.plugin2.main.client.LiveConnectSupport$PerAppletInfo$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.plugin2.main.client.LiveConnectSupport$PerAppletInfo.doObjectOp(Unknown Source)
at sun.plugin2.main.client.LiveConnectSupport$PerAppletInfo$LiveConnectWorker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
P.S.: Applet is signed.

The problem is the call from JavaScript. If you are using JavaScript to call your method, the permissions of the call get down to the intersection of the JavaScript bridge's permissions (i.e. nothing) and the permissions of your own code - even if your own code is signed.
To avoid this, and use the full privileges of your applet's code, put the security-relevant parts inside a AccessController.doPrivileged(...) call. (Of course, your applet should first check that this can't do anything malicious.)
I have no idea why it works if you are using the IP address directly instead of localhost, though.

localhost is an alias for 127.0.0.1 so you may have to set/fix it in your enviroment. Under Windows you have to edit the file C:\Windows\System32\drivers\etc\hosts.

localhost is typically resolved to both ::1 and 127.0.0.1 and the OS/libc is usually set up so that IPv6 is preferred in these circumstances.
Therefore, it's likely you're allowing only 127.0.0.1 and not IPv6 connections from ::1.

Access Denied Java FileWriter / FileInputStream

My program downloads a websites source code, modifies it, creates the file, and then reuploads it through the FTP. However, I receive the following error when trying to open the created file:
java.io.FileNotFoundException: misc.html (Access is denied)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(Unknown Source)
at Manipulator.uploadSource(Manipulator.java:63)
at Start.addPicture(Start.java:130)
at Start$2.actionPerformed(Start.java:83)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
When I navigate to the folder directory and attempt to open "misc.html" with Notepad I receive Access is Denied. My code is fairly simple:
File f = new File(page.sourceFileName);
try {
FileWriter out = new FileWriter(f);
out.write(page.source);
out.close();
} catch (IOException e) {
e.printStackTrace();
} InputStream input = new FileInputStream(f);
This is the vital excerpt from my program. I have copied this into a different test program and it works fine, I create a misc.html file and reopen it with both FileInputStream and manually.
I would be worried about Administrator rights but the Test program works fine when I run it RIGHT after the problem program. I also have checked if the file exists and is a file with File methods and it is as well. Is this a result of me not closing a previous Input/Output properly? I've tried to check everything and I am fairly positive I close all streams as soon as they finish...
Help! :)
UPDATE:
If I comment out the FileInputStream code and just leave the FileWriter the File still is Access Denied. If I remove the FileWriter code, no File is made (so it's certainly not overwriting anything). The FileWriter code is the first time the file is made and no exception is thrown - but I still cannot manually open the file.

If you really have sufficient permissions to read that file, then the thing I can notice is that you are not using streams properly:
out.write(page.source); // if this throws an exception
out.close(); //this is not called, and the file remains open
You must close the streams in a finally block.
FileWriter fw = null;
try {
fw = new FileWriter(f);
fw.write(page.source);
} catch (IOException ex) {
ex.printStackTrace(); //consider a logger
} finally {
IOUtils.closeQuietly(fw);
}
The same goes for the InputStreams
Now, the IOUtils.closeQuietly(fw) is a bit controversial, since it will not report an exception that happens during the closing of a file. And it is from apache commons-io (external dependency). You can replace it with another try-catch inside the finally and then a null check, before calling close(). Luckily this will be a lot easier in Java 7.

This kind of error seems to happen when trying to work on a directory. Sure you don't?
Make some extra log output what you open and close, and return here....

Does your program run in as an Applet or WebStart application? If so, it is likely that the JVM sandbox is preventing your (untrusted) code from accessing the local filesystem.