I have checked multiple posts about why my i'm getting a error saying that there is a NullPointerException at this line
JLabel label = new JLabel(new ImageIcon(getClass().getResource("image.png")));
Every posts saying that its because it can't find the image. I have tried changing the code to absolute which does not change anything. I have moved the image into the src folder and the package for the program but nothing seems to work. Right now the image is in the src folder if that helps with someone solving why it does not work
Here is the Error.
Exception in thread "main" java.lang.NullPointerException
at javax.swing.ImageIcon.<init>(Unknown Source)
Then it points to that line of code.
The getResource() call is returning null (which you're not checking) and you're then getting the NullPointerException.
When you use getResource() it looks for the file in the same directory as the class -- including the package. So if this is in a com.example package, it'll need to be in com/example/image.png.
If the file is at the root of the classes directory or jar file, then you need to prefix it with /:
JLabel label = new JLabel(new ImageIcon(getClass().getResource("/image.png")));
Related
I've got following maven project structure as also seen in here (ProjectStructure) :
-maws20.algorithm
|-src/main/resources
|-images
|-menuBanner
|-linearSearchMenuBannerUnsorted.png
|-src/main/java
|-linearSearch.menu
|-LinearSearchMenuBanner.java
I am trying to load that .png image inside of the LinearSearchMenuBanner.java-File with the following Line:
#Override
public Image loadBackgroundImage() {
return new Image(LinearSearchMenuBanner.class.
getResource("/images/menuBanner/linearSearchMenuBannerUnsorted.png").toString());
}
Is this not the correct relative path? Because I get the following error:
...
Caused by: java.lang.NullPointerException: Cannot invoke "java.net.URL.toString()" because the return value of "java.lang.Class.getResource(String)" is null
at linearSearch.menu.LinearSearchMenuBanner.loadBackgroundImage(LinearSearchMenuBanner.java:20)
...
(Line 20 is the line shown above)
I thought I understood the relative paths in Java. ^^'
Thank you for any help.
Remove the first back slash /, which actually means absolute path not the relative path.
Try this:
#Override
public Image loadBackgroundImage() {
File resource = new ClassPathResource("images/menuBanner/linearSearchMenuBannerUnsorted.png").getFile();
return new Image(new String(Files.readAllBytes(resource.toPath()));
}
To know more, you can visit this link: spring-classpath-file-access
Thanks for all your help. I don't know what went wrong, but when i create a completly new Workspace after that create all files new and copy the source code to the new files. Then it works fine.
I dont know why...
But thank you very much :)
I guess this is related to your packaging. The image needs to be on the servers file system, the JAR resources will not work!
ClassPathResource
Supports resolution as java.io.File if the class path resource resides in the file system, but not for resources in a JAR. Always supports resolution as URL.
You are in package search.menu and you need to access the file resource in images/menuBanner So you need to load a resource:
new ClassPathResource(“../../images/menuBanner/linearSearchMenuBannerUnsorted.png
“, LinearSearchMenuBanner
.class).getFile();
Hava a look into other options here:
https://www.baeldung.com/spring-classpath-file-access
We're writing an Java application using JavaFX. At this time we have 3 different forms:
Login
Game window
Registration
For our next iteration, we want to implement the Registration form, but we get the IOException error Unknown Path
It's about this piece of code:
FXMLLoader registrationLoader = new FXMLLoader();
try{
mainroot = (Parent)registrationLoader.load(this.getClass().getResource("FXMLRegistration.fxml").openStream());
Stage registrationStage = new Stage();
Scene scene = new Scene(mainroot);
registrationStage.setScene(scene);
registrationStage.setTitle("Register your account");
registrationStage.show();
} catch(IOException ex)
{
System.out.print(ex.getMessage());
}
The above code is working when I change FXMLRegistration.fxml to FXMLDocument.fxml or FXMLLoader.fxml.
When I change
mainroot = (Parent)registrationLoader.load(this.getClass().getResource("FXMLRegistration.fxml").openStream());
to
mainroot = (Parent)registrationLoader.load(Paths.get("src/hackattackfx/FXMLRegistration.fxml").toUri().toURL());
source
I get the absolute path in the debugger output, which is correct when I use it with the file command in terminal.
I hope someone could help us with this error.
Thanks in advance!
EDIT
I Changed some code to the following:
FXMLLoader registrationLoader = new FXMLLoader(getClass().getResource("/FXMLRegistration.fxml"));
mainroot = (Parent)registrationLoader.load();
but this will return an IllegalStateException: Location is not set.
When I remove / before /FXMLRegistration.fxml, I get to my catch block printing the full path of the file:
file:/Users/juleskreutzer/Documents/github/PTS3/HackAttackFX/dist/run1793658053/HackAttackFX.jar!/hackattackfx/FXMLRegistration.fxml
Also changing the path to src/hackattackfx/FXMLRegistration.fxml will give the IllegalStateException: Location not set.
Project Structure
We use different packages in our application. all these packages are within the default package: hackattackfx
The packages in the default package are:
Default Package
Exceptions
Interfaces
enums
Resources
Templates
JSON Package
My FXML documents are located in the default package (hackattackfx). If it's not 100% clear how I arranged my files, please take a look at my Github repo
So, I got all curious to find out the root cause, I cloned the repo and found that the actual issue was the following error and the one that was posted by the OP in the question
Caused by: java.lang.NullPointerException
at hackattackfx.FXMLRegistrationController.initialize(FXMLRegistrationController.java:67)
Which means that in the controller pane was null.
This was because the fxml was missing a declaration of fx:id .
Add fx:id="pane" to the AnchorPane declaration of FXMLRegistration.fxml and things should just work fine.
You need to start your Path with /
this is working for me:
final String fxmlPath = "/fxml/Main.fxml";
final FXMLLoader loader = new FXMLLoader(this.getClass().getResource(fxmlPath));
Main.fxml is located in the resource folder (for me: /src/main/resources/fxml/)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at javax.swing.ImageIcon.(ImageIcon.java:205)
JLabel background = new JLabel(new ImageIcon(getClass().getResource("/resources/splashscreen.jpeg")));
The above line is the exact line throwing the exception, and it makes me believe that the location of the file is not correct, but I have tried numerous things but to no success.
The folder structure seems to be correct, the image is within the resources folder which is within the project folder, and the folder(with the image) is next to the src folder not within. This application has to have the ability of being used offline otherwise I would just use the URL. Is there a known bug with this in the Eclipse IDE?
Figured it out. It seems that I was putting the file in the wrong location, putting it with the .class files solved the problem. Not sure if this was a proper solution or just a work around unfortunately. I had to go back to the basics .java files are compiled and the .class files are actually running, and I need to backtrack from the current working directory.
try this,put your image in an external folder outside source folder called Images
and after try:
public class Test{
public Test()
{
JFrame frame= new JFrame();
JLabel label = new JLabel(new ImageIcon("Images/image.jpeg"));
frame.getContentPane().add(label);
Container log = login.getContentPane();
log.setBackground(Color.WHITE);
frame.setVisible(true);
frame.setSize(400,400);
frame.setLocationRelativeTo(null);
}
public static void main(String[] args)
{
new Test();
}
try to launch this app.
Actually, you have to put "resource" folder into source folder in this case.
Seems like "/resources/splashscreen.jpeg" is an absolute path. Try without the leading slash or give the "real" absolute path.
Edit: I'm pretty sure the file is not found and getResource() returns null.
Why not try to get the file size? Fiddle around with this:
File f = new File("/resources/splashscreen.jpeg");
long length = f.length();
until length != 0
:-)
I just fiddled with the same problem and #OiRC answer helped me ALOT. I followed youtube tutorials to get code as follows:
ImageIcon helpIcon = new ImageIcon(getClass().getResource("helpIcon.png"));
lbl_helpIcon = new JLabel(new ImageIcon("helpIcon.png"));
lbl_helpIcon.setBounds(178, 11, 139, 62);
lbl_helpIcon.setIcon(helpIcon);
I kept getting a NullPointerException on
ImageIcon helpIcon = new ImageIcon(getClass().getResource("helpIcon.png"));
Until I tried this
lbl_helpIcon = new JLabel(new ImageIcon("helpIcon.png"));
lbl_helpIcon.setBounds(178, 11, 139, 62);
Worked like a charm! btw I stored my icon image like so
I am relatively new to Java, so bear with me.
I am completing a tutorial on LWUIT, and just want to load a simple theme, created using the editor. Here is the code in question:
try
{
Container container = c.getContainer();
container.setVisible(true);
Display.init(container);
Display.getInstance().setPureTouch(true);
//Resources r = Resources.open(getClass().getResourceAsStream("/res/Theme.res"));
Resources r = Resources.open("/res/Theme.res");
UIManager.getInstance().setThemeProps(r.getTheme("Simple"));
}
When I use the first (commented out) statement, I get
*** Signal: alarm { "name":"XletException", "domain":"ams", "appId":"com.thomasdge.xlet.hellojamaica.HelloJamaica", "msg":"XletAction['initXlet'] resulted in exception com.aicas.xlet.manager.AMSError: running xlet code caused java exception: initXlet() resulted in exception: java.lang.NullPointerException: <null>.read()I", "data":{ } }
When I use the other, I get
java.io.IOException: /res/Theme.res not found
I have my Theme.res file in /res/Theme. I have also tried it directly in the root, as well as /src. Same results for each.
Any ideas?
If you put the res file in that folder, you will need to go down one level. I recommend you to put the res in the src folder. So, /src/Theme.res. In the code you will only need to write Resources r = Resources.open("/Theme.res");
If resource file placed in res folder, you need to add res folder in project properties. Also you mentioned, the problem even in /src folder, I feel you didn't change the path. Just use Resources.open("/Theme.res") when you use /src folder. Also check the theme name. This should work.
I have added an image for my button,but when I run that frame this exception will be thrown .why?please help me.
init:
deps-jar:
compile-single:
run-single:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at javax.swing.ImageIcon.<init>(ImageIcon.java:138)
at ClientGUI.IdAndPasswordFrame.initComponents(IdAndPasswordFrame.java:91)
at ClientGUI.IdAndPasswordFrame.<init>(IdAndPasswordFrame.java:22)
at ClientGUI.IdAndPasswordFrame$4.run(IdAndPasswordFrame.java:200)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)
BUILD SUCCESSFUL (total time: 1 second)
line 138:
public ImageIcon (URL location) {
this(location, location.toExternalForm());
}
line91:
jButton1.setIcon(new javax.swing.ImageIcon(getClass().getResource("/Images/yahoo_1.gif"))); // NOI18N
I use this poor checking (Peter Lang recommended)which is:System.out.println(getClass().getResource("/Images/yahoo_1.gif")); and it returns null,why? please help me.
This means, that getClass().getResource("/Images/yahoo_1.gif") returns null.
JavaDoc states that this happens if
the resource could not be found or the invoker doesn't have adequate privileges to get the resource.
Check if getResource really returns null:
System.out.println(getClass().getResource("/Images/yahoo_1.gif"));
Make sure that your path is correct and that it is in your classpath.
EDIT:
I just tried it with NetBeans. I created the following structure
Source Packages
Images
yahoo_1.gif
and your code worked fine. Is this your structure?
Try to right-click on your application and select Clean and Build.
In order to fix this, the images need to be copied in the bin directory - not in src directory.
Otherwise you will get null all the time on getClass().getResource("image.png").
The path is not null and you can set it as the above - only if you copy the images that you need inside the binary directory, where .class files for your project are located.
This fixed the problem. Let me know if I helped in this.
Ioana
I had the same problem. What worked for me was:
Look into the jar file or in the bin folder(the one with .class files) and see the path of image.
List item
It looks like getClass().getResource("/Images/yahoo_1.gif") returns null i.e. the .gif cannot be found on your classpath. (Images versus images maybe?)
The URL being passed in is null from this line:
getClass().getResource("/Images/yahoo_1.gif")
From the JDK documentation:
[getResource(..) returns] A URL object for reading the resource,
or null if the resource could not be
found or the invoker doesn't have
adequate privileges to get the
resource
Maybe you meant ("Images/yahoo_1.gif") - i.e. relative path not absolute?
private class HandlerClass implements ActionListener{
public void actionperformed(ActionEvent event){
JOptionPane.showMessageDialog(null, String.format("%s", event.getActionCommand()));
}
}
After reviewing some things when trying to add an image I was presented with the same problem that usually occurs in project with maven.
I found a solution that uses the full path to be able to access the image. Also, create a function that returns an icon with the image and automatically scaled according to the dimensions that are sent to it.
Path -> directory where the image is located, width -> width of the icon, heigth-> height of the icon I hope it serves you, this is my first contribution in the community
public Icon getIcon(String ruta, int width, int heigth) {
Image image = (new ImageIcon(ruta)).getImage().getScaledInstance(width, heigth, 0);
Icon mIcono = new javax.swing.ImageIcon(image);
return mIcono;
}