JavaFX Location is not set error message

问题:

I have problem when trying to close current scene and open up another scene when menuItem is selected. My main stage is coded as below:

public void start(Stage primaryStage) throws Exception {
    primaryStage.setTitle("Shop Management");
    FXMLLoader myLoader = new FXMLLoader(getClass().getResource("cartHomePage.fxml"));

    Pane myPane = (Pane) myLoader.load();

    CartHomePageUI controller = (CartHomePageUI) myLoader.getController();

    controller.setPrevStage(primaryStage);
    Scene myScene = new Scene(myPane);
    primaryStage.setScene(myScene);
    primaryStage.show();
}

When the program is executed, it will go to the cartHomePage.fxml. From there, I can select to go to create product or create category when the menu item is selected. Here is my action event:

Stage prevStage;

public void setPrevStage(Stage stage){
     this.prevStage = stage;
}

 public void gotoCreateCategory(ActionEvent event) throws IOException {
  Stage stage = new Stage();
    stage.setTitle("Shop Management");
    FXMLLoader myLoader = new FXMLLoader(getClass().getResource("createCategory.fxml"));
    Pane myPane = (Pane) myLoader.load();            
    Scene scene = new Scene(myPane);
    stage.setScene(scene);
    prevStage.close();
    setPrevStage(stage);
    stage.show();       
}

//Method to change scene when menu item create product is on click
@FXML
public void gotoCreateProduct(ActionEvent event) throws IOException {
   Stage stage = new Stage();
    stage.setTitle("Shop Management");
    FXMLLoader myLoader = new FXMLLoader(getClass().getResource("creatProduct.fxml"));
    Pane myPane = (Pane) myLoader.load();            
    Scene scene = new Scene(myPane);
    stage.setScene(scene);
    prevStage.close();
    setPrevStage(stage);
    stage.show();      
}

However, I can only switch the stage once. For example, my default page is cartHomePage.fxml. When I run the program, first I go to create product stage. After that, I cannot go to anywhere any more. The error message is:

java.lang.IllegalStateException: Location is not set.
and Null Pointer Exception

I did set the stage after I close it and pass it around. I wonder which part went wrong.

Thanks in advance.

回答1:

I had this problem and found this post. My issue was just a file name issue.

FXMLLoader(getClass().getResource("/com/companyname/reports/" +
report.getClass().getCanonicalName().substring(18).replaceAll("Controller", "") +
".fxml"));

Parent root = (Parent) loader.load();

I have an xml that this is all coming from and I have made sure that my class is the same as the fxml file less the word controller.

I messed up the substring so the path was wrong...sure enough after I fixed the file name it worked.

To make a long story short I think that the problem is either the filename is named improperly or the path is wrong.

ADDITION: I have since moved to a Maven Project. The non Maven way is to have everything inside of your project path. The Maven way which was listed in the answer below was a bit frustrating at the start but I made a change to my code as follows:

FXMLLoader loader = new FXMLLoader(ReportMenu.this.getClass().getResource("/fxml/" + report.getClass().getCanonicalName().substring(18).replaceAll("Controller", "") + ".fxml"));

回答2:

I was getting this exception and the "solution" I found was through Netbeans IDE, simply:

1. Right-click -> "Clean and Build"
   
2. Run project again

I don't know WHY this worked, but it did!

回答3:

I converted a simple NetBeans 8 Java FXML application to the Maven-driven one. Then I got problems, because the getResource() methods weren't able to find the .fxml files. In mine original application the fxmls were scattered through the package tree - each beside its controller class file. After I made Clean and build in NetBeans, I checked the result .jar in the target folder - the .jar didn't contain any fxml at all. All the fxmls were strangely disappeared.

Then I put all fxmls into the resources/fxml folder and set the getResource method parameters accordingly, for example: FXMLLoader(App.class.getClassLoader().getResource("fxml/ObjOverview.fxml")); In this case everything went OK. The fxml folder appeared int the .jar's root and it contained all my fxmls. The program was working as expected.

回答4:

I know this is a late answer, but I hope to help anyone else who has this problem. I was getting the same error, and found that I had to insert a / in front of my file path. The corrected function call would then be:

FXMLLoader myLoader = new FXMLLoader(getClass().getResource("/createCategory.fxml"));
//                                                           ^

回答5:

I tried a fast and simple thing:

I have two packages -> app.gui and app.login

In my login class I use the mainview.fxml from app.gui so I did this in the login.fxml

FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("../gui/MainView.fxml"));

And it works :)

回答6:

This is often not getting the location path correct. It is important to realize that the path starts from the current package which the code resides in and not the root of the project. As long as you get this relative path correct, you should be able to steer clear of this error in this case.

回答7:

I think problem is either incorrect layout name or invalid layout file path.

for IntelliJ, you can create resource directory and place layout files there.

FXMLLoader loader = new FXMLLoader();
loader.setLocation(getClass().getResource("/sample.fxml"));
rootLayout = loader.load();

回答8:

I've had the same issue in my JavaFX Application. Even more weird: In my Windows developement environment everything worked fine with the fxml loader. But when I executed the exact same code on my Debian maschine, I got similar errors with "location not set".

I read all answers here, but none seemed to really "solve" the problem. My solution was easy and I hope it helps some of you:

Maybe Java gets confused, by the getClass() method. If something runs in different threads or your class implements any interfaces, it may come to the point, that a different class than yours is returned by the getClass() method. In this case, your relative path to creatProduct.fxml will be wrong, because your "are" not in the path you think you are...

So to be on the save side: Be more specific and try use the static class field on your Class (Note the YourClassHere.class).

@FXML
public void gotoCreateProduct(ActionEvent event) throws IOException {
   Stage stage = new Stage();
    stage.setTitle("Shop Management");
    FXMLLoader myLoader = new FXMLLoader(YourClassHere.class.getResource("creatProduct.fxml"));
    Pane myPane = (Pane) myLoader.load();            
    Scene scene = new Scene(myPane);
    stage.setScene(scene);
    prevStage.close();
    setPrevStage(stage);
    stage.show();      
}

After realizing this, I will ALWAYS do it like this. Hope that helps!

回答9:

The answer below by CsPeitch and others is on the right track. Just make sure that the fxml file is being copied over to your class output target, or the runtime will not see it. Check the generated class file directory and see if the fxml is there

回答10:

I mean something like this:

FXMLLoader myLoader = null; Scene myScene = null; Stage prevStage = null;

public void start(Stage primaryStage) throws Exception {
  primaryStage.setTitle("Shop Management");
  myLoader = new FXMLLoader(getClass().getResource("cartHomePage.fxml"));
  Pane myPane = (Pane) myLoader.load();
  CartHomePageUI controller = (CartHomePageUI) myLoader.getController();
  controller.setPrevStage(primaryStage);
  myScene = new Scene(myPane);
  primaryStage.setScene(myScene);
  primaryStage.show();
}

After that

public void setPrevStage(Stage stage){
    this.prevStage = stage;
}

public void gotoCreateCategory(ActionEvent event) throws IOException {
    Stage stage = new Stage();
    stage.setTitle("Shop Management");
    myLoader = new FXMLLoader(getClass().getResource("createCategory.fxml"));
    Pane myPane = (Pane) myLoader.load();            
    Scene scene = new Scene(myPane);
    stage.setScene(scene);
// prevStage.close(); I don't think you need this, closing it will set preStage to null   put a breakpoint after this to confirm it
    setPrevStage(stage);
    stage.show();       
}

//Method to change scene when menu item create product is on click
@FXML
public void gotoCreateProduct(ActionEvent event) throws IOException {
    Stage stage = new Stage();
    stage.setTitle("Shop Management");
    myLoader = new FXMLLoader(getClass().getResource("creatProduct.fxml"));
    Pane myPane = (Pane) myLoader.load();            
    Scene scene = new Scene(myPane);
    stage.setScene(scene);
// prevStage.close(); I don't think you need this, closing it will set preStage to null put a breakpoint after this to confirm it
    setPrevStage(stage);
    stage.show();      
}

Try it and let me know please.

回答11:

That happened to me an i found the solution. If u build your project with your .fxml files in different packages from the class that has the launch line (Parent root = FXMLLoader.load(getClass().getResource("filenamehere.fxml"));) and use a relative path your windows except from the first one wont launch when your run the jar. To keep it short place the .fxml file in the same package with the class that launches it and set the path like this ("filenamehere.fxml") and it should work fine.

回答12:

I had the same problem.

after a few minutes, i figured it that i was trying the load the file.fxml from wrong location.

FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("/[wrong-path]/abc.fxml"));
fxmlLoader.setClassLoader(getClass().getClassLoader());
fxmlLoader.setRoot(this);
fxmlLoader.setController(this);
fxmlLoader.load();

回答13:

I've stumbled upon the same problem. Program was running great from Eclipse via "Run" button, but NOT from runnable JAR which I'd exported before. My solution was:

1) Move Main class to default package

2) Set other path for Eclipse, and other while running from the JAR file (paste this into Main.java)

public static final String sourcePath = isProgramRunnedFromJar() ? "src/" : "";
public static boolean isProgramRunnedFromJar() {
    File x = getCurrentJarFileLocation();
    if(x.getAbsolutePath().contains("target"+File.separator+"classes")){
        return false;
    } else {
        return true;
    }
}
public static File getCurrentJarFileLocation() {
        try {
            return new File(Main.class.getProtectionDomain().getCodeSource().getLocation().toURI().getPath());
        } catch(URISyntaxException e){
            e.printStackTrace();
            return null;
        }
}

And after that in start method you have to load files like this:

FXMLLoader loader = new FXMLLoader(getClass().getResource(sourcePath +"MainScene.fxml"));

It works for me in Eclipse Mars with e(fx)clipse plugin.

回答14:

For Intellij users, my issue was that the directory where I had my fxml files (src/main/resources), was not marked as a "Resources" directory.

Open up the module/project settings go to the sources tab and ensure that Intellij knows that the directory contains project resource files.

回答15:

mine was strange... IntelliJ specific quirk.

I looked at my output classes and there was a folder:

x.y.z

instead of

x/y/z

but if you have certain options set in IntelliJ, in the navigator they will both look like x.y.z

so check your output folder if you're scratching your head

回答16:

I had the same problem. It's a simple problem of not specifying the right path.

Right click on the on your .fxml file and select properties (for those using eclipse won't differ that much for another IDE) and then copy the copy the location starting from /packagename till the end and that should solve the problem

回答17:

FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("../view/Main.fxml")); 

in my case i just remove ..

FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("/view/Main.fxml"));