CODEWITHSUNDEEP
javamavenopencsv
user7269729
user7269729

Reputation:

Can't locate resource file under Maven

I am writing simple application and I got kinda lost - here is the deal:

Project structure is as follows:

ProjectApp
|-- pom.xml
`-- .idea
`-- src
    -- main
       |-- java
       |   `-- myapp
       |       |-- components
       |       |   <some files>
       |       |-- controllers
       |       |   <some files>
       |       |-- repositories
       |       |   <some files>
       |       |-- Main.java
       `-- resources
           |-- database
           |    -- Data.csv
           `-- fxml
                -- Scene.fxml

As you can see in the resources folder I have 2 subfolders, one of them is for data another one for fxmls (this app is simple JavaFX application). Now, here is the problem:

Code I use for loading scene

String SCENE_PATH = "/fxml/Scene.fxml";
Parent root = FXMLLoader.load(getClass().getResource(SCENE_PATH));

Code I use for loading data (I am using opencsv library)

String DATA_PATH = "database/ClientData.csv";
ClassLoader classLoader = getClass().getClassLoader();
File dataFile = new File(classLoader.getResource(DATA_PATH).getFile());
CSVReader reader = new CSVReader(new FileReader(clientDataFile));

I hope I am providing enough context here, if not, please let me know and I will edit (pom.xml is very basic, nothing fancy there). Now, this WORKS under IntelliJ, but when I try to run it with maven, like:

mvn clean package
java -cp ./target/ProjectApp.jar myapp.Main

from ProjectApp directory, application runs, but I get FileNotFoundException (it loads fxml files, but no csv files - i get working application, but without access to data). Also, why when accessing fxml files I must provide (NullPointerException if not) "/" at the beginning of the path, but when I am accessing csv files I must not do that (so path "/database/ClientData.csv" results in NullPointerException)?

@EDIT

Actually problem seemed to be with a packaging - when I package application to jar file, it adds exclamation mark to the path, so the path is incorrect (or at least I think so).

Upvotes: 0

Views: 957

Answers (1)

mhasan
mhasan

Reputation: 3709

accessing csv files I must not do that (so path "/database/ClientData.csv" results in NullPointerException)

Because when you try to load resource from getClass().getClassLoader() it doesn't take path starting with /

why when accessing fxml files I must provide (NullPointerException if not) "/" at the beginning of the path

Because if you do not provide the / at the start of your file [fxml/Scene.fxml] it will tried to be located from the package of the class on which the method is called, which will be like myapp/controller/ClassName... or so on, hence it will fail to load the resource.

But when you provide the / at the start of your file [fxml/Scene.fxml] it will tried to be located from the root of the classpath, hence it is located succesfully

Upvotes: 1

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