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I'm getting this error

Exception in thread "main" java.lang.NoClassDefFoundError: javafx/application/Ap plication at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(Unknown Source) at java.security.SecureClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.access$100(Unknown Source) at java.net.URLClassLoader$1.run(Unknown Source) at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source) Caused by: java.lang.ClassNotFoundException: javafx.application.Application at java.net.URLClassLoader$1.run(Unknown Source) at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) ... 13 more

When trying to run my class file, this is the source

import javafx.application.Application; import javafx.fxml.FXMLLoader; import javafx.scene.Parent; import javafx.scene.Scene; import javafx.stage.Stage; import java.util.concurrent.Executor; public class TestApplication extends Application{ @Override public void start(Stage stage) throws Exception { new TestApplication(); } public TestApplication() { try{ final Parent root = FXMLLoader.load(Executor.class.getResource("test.fxml")); final Stage stage = new Stage(){{ setScene(new Scene(root, 300, 250)); setTitle("Test"); setResizable(false); show(); }}; }catch(Exception e){ e.printStackTrace(); } } }

The fxml file contains a simple gui.

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  • 1
    possible duplicate of jdk1.7's javac can't find javafx jar without -cp option Commented Jun 1, 2013 at 3:45
  • I declared my classpath to the directory of jfxrt.jar and I'm getting this error now: Error: Could not find or load main class Commented Jun 1, 2013 at 5:44
  • 1
    You need to have your current directory on the classpath => for details see: Compile JavaFX 2.0 Manually Commented Jun 1, 2013 at 5:54

12 Answers 12

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15

I've worked on this very same issue for the past few hours. Even though I haven't seen it written explicitly, it appears that you MUST use one of the JavaFX packaging tools, which is either an Ant task or the javafxpackager executable. (See http://docs.oracle.com/javafx/2/deployment/packaging.htm, section 5.3.1). The NetBeans IDE uses Ant to package the code. (I'm using IntelliJ)

When you use one of those packaging methods, in addition to all of your application's code and resources, it also adds the following to your output JAR file:

/com/javafx/main/Main$1.class /com/javafx/main/Main$2.class /com/javafx/main/Main.class /com/javafx/main/NoJavaFXFallback.class

With these in place, you can run the app from the command line:

java -jar outjar.jar

and all works fine. If I remove the extra com.javafx.main files, the app does not run.

To double-check this, I looked at all four JAR files in the JavaFX samples (BrickBreaker, Ensemble, FXML-LoginDemo, and SwingInterop). They all have the "extra" files, too.

For my small test app, I used this command line to build an "executable" JAR file:

javafxpackager -createjar -appclass sample.Main -outfile outjar -v -nocss2bin -srcdir C:\workspaces\garoup1\out\production\javafx1

Hope this helps!

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2 Comments

I am using Intellij and I got this problem. But I saw that it uses ant to build and javafxpacker to deploy. Still it does not have this fallback class. Are you sure there is no workaround this from within Intellij?
You see this error message even you have Java 1.8 installed and have the CLASSPATH point to javafx purposely. This happened to the DbSchema 7.6.5 where it hard-coded the classpath to excluded javafx. After I edited the shell script, this problem disappeared.
8

I had the same problem and below steps helped me to solve it,

Adding the vm arguments while running the application,

--module-path /home/user/Java-libraries/openjfx-11.0.2_linux-x64_bin-sdk/javafx-sdk-11.0.2/lib/ --add-modules javafx.controls,javafx.fxml

Note:

  • The --module-path will contain the jars of Java fx
  • I used open-jdk 13

Configure this in your eclipse (If you are using so) or you can just compile and run like,

Compile

javac --module-path /path/to/java-fx-libs/ --add-modules javafx.controls,javafx.fxml *.java

Run

java --module-path /path/to/java-fx-libs/ --add-modules javafx.controls,javafx.fxml MyMainClass
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7

I believe that my example will help someone. I had not succeeded with building REALLY executable jar file, that can be run by click from any place/directory with Java 8. Moving to Java 11 and few other twicks did the business.

  1. Move to Java 11. Specify SDK, other staff in IDE, add this to pom.xml

     <maven.compiler.source>11</maven.compiler.source> <maven.compiler.target>11</maven.compiler.target>

  2. Add JavaFX dependencies

     <!--JavaFX--> <dependency> <groupId>org.openjfx</groupId> <artifactId>javafx</artifactId> <version>15.0.1</version> <type>pom</type> </dependency> <!--JavaFX-controls--> <dependency> <groupId>org.openjfx</groupId> <artifactId>javafx-controls</artifactId> <version>15.0.1</version> </dependency>

  3. Build application

  4. Create wrapper class for your Main class, which extends Application

     public class Launcher { public static void main(String[] args) { Main.main(args); } }

  5. Add the following to pom.xml

     <build> <resources> <resource> <directory>src/main/resources</directory> </resource> </resources> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-jar-plugin</artifactId> <version>3.2.0</version> <configuration> <archive> <manifest> <addClasspath>true</addClasspath> <mainClass>path-to-launcher.Launcher</mainClass> </manifest> <manifestEntries> <Class-Path>.</Class-Path> </manifestEntries> </archive> </configuration> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-assembly-plugin</artifactId> <version>3.3.0</version> <configuration> <finalName>final-jar-file-name</finalName> <archive> <manifest> <mainClass>path-to-launcher.Launcher</mainClass> </manifest> </archive> <descriptorRefs> <descriptorRef>jar-with-dependencies</descriptorRef> </descriptorRefs> <appendAssemblyId>false</appendAssemblyId> </configuration> <executions> <execution> <id>make-assembly</id> <phase>package</phase> <goals> <goal>single</goal> </goals> </execution> </executions> </plugin> </plugins> </build>

  6. Run this maven command

     mvn clean -Dmaven.clean.failOnError=false compile assembly:single -DskipTests=true

The jar file with specified name will appear in target directory. It will be executable independent from where you are running it.

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In my case, I only needed to compile with JDK 11 and understand that my problem was the javafx.util.Pair, add only the javafx-controls redeploy dependency and the issue was fixed.
4

Using java 8 shouldn't give this problem but it did for me

I created my jar initially from Eclipse Export -> Runnable Jar and it was fine. When I moved to Maven it failed with the above.

Comparing the two jars showed that nothing fx related was packaged with the jar (as I'd expect) but that the Eclipse generated manifest had Class-Path: . in it. Getting maven to package the jar with the following worked for me (with Java 8)

 <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-jar-plugin</artifactId> <configuration> <archive> <manifest> <addClasspath>true</addClasspath> <mainClass>com.pg.fxapplication.Main</mainClass> </manifest> <manifestEntries> <Class-Path>.</Class-Path> </manifestEntries> </archive> </configuration> </plugin> </plugins> </build>
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3

I know it may not be the "proper" way of launching an javafx application but i have struggled with this problem for some time and came up with a workaround that does not require to use any external packaging applications, force you to use ant or maven plugin (which conflicts with the shade plugin) etc...

The solution uses Utils4j to load jfxrt dynamically at runtime. You cannot load it in a class extending javafx.application.Application, do it in a separate class and name it for example: Launcher

import org.fuin.utils4j.Utils4J public class Launcher { public static void main(String[] args) { Utils4J.addToClasspath("file:///"+System.getProperty("java.home")+ File.separator+"lib"+File.separator+"jfxrt.jar"); // CODE TO RUN YOUR CLASS THAT EXTENDS javafx.application.Application goes here. } }

you can include Utils4j with your project (if using maven):

 <dependency> <groupId>org.fuin</groupId> <artifactId>utils4j</artifactId> <version>0.7.0</version> </dependency>
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1

I use maven and I just run this mvn install:install-file -Dfile="/Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home/jre/lib/jfxrt.jar" -DgroupId=com.oracle.javafx -DartifactId=javafx -Dversion=2.2 -Dpackaging=jar in terminal(Maybe a little difference in Windows.). Then maven will install jfxrt.jar then you can simply reference it as 

<dependency> <groupId>com.oracle.javafx</groupId> <artifactId>javafx</artifactId> <version>2.2</version> </dependency>
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1

If you are using netbeans like me and you have two versions of JDK installed, then you should change the classpath to the appropriate java installation in the config file. This is also a bug in Netbeans: There are two ways to do it:
Either start NetBeans with --jdkhome by executing this:

"C:\Program Files\NetBeans Dev 201402160001\bin\netbeans.exe" --jdkhome "C:\Program Files\Java\jdk1.7.0_51"

Or set the "netbeans_jdkhome" property in /etc/netbeans.conf e.g.

# Default location of JDK, can be overridden by using --jdkhome <dir>: netbeans_jdkhome="C:\Program Files\Java\jdk1.7.0_51"
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1

IntelliJ and maybe other IDE's do not refactor your Run/Debug configuration. You must manually change your package name preceding the name of your Main class. For instance, change 'sample.Main' to 'com.company.package.ui.Main' so it will launch correctly next time you try to run it. The IDE might have already marked the Run/Debug button with a red cross because it couldn't find the main class. It also gives a warning when you open the Run/Debug configuration.

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1

I already answered it on "Ask ubntu". I recommend you to go with https://openjfx.io/openjfx-docs/ .i am using Eclipse IDE but it works for all IDE

Then you can refer to this global variable when setting the VM options as:

In IDE Right-click on project->Run As -> Run Configuration ->Arguments->VM Arguments

For Windows,

--module-path "\path to javafx\lib" --add-modules javafx.controls,javafx.fxml

For Linux,

--module-path /path to javafx/lib --add-modules javafx.controls,javafx.fxml

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0

I'm developing on Linux a simple WebApp i got the same error, but is really easy to fix it (assuming you are developing on the command line as myself).

cat compile.sh #!/bin/bash /usr/lib/jvm/jdk1.7.0_25/bin/javac WebViewSample.java -cp /usr/lib/jvm/jdk1.7.0_25 /jre/lib/jfxrt.jar $ cat run.sh #!/bin/sh JAVA_HOME=/usr/lib/jvm/jdk1.7.0_25/bin/ CLASSPATH=/usr/lib/jvm/jre1.7.0_25/lib/jfxrt.jar:. $JAVA_HOME/java -cp $CLASSPATH WebViewSample $* 2>&1 /dev/null | awk -F\| '{ print $2"|"$3 ; exit $1 }' exit $?
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0

I had a problem of not finding the Pair class from javafx.

It seems that vanilla eclipse (without the e(fx)clipse extension) doesn't search the javaFX runtime jar included with java.

I just added to my eclipse project build path this external jar (or if you are in a debug configuration, add the external jar in the JRE tab of the debug configuration):

$JAVA_HOME/jre/lib/ext/jfxrt.jar

(replace JAVA_HOME with your jdk folder)

For me it was in /installs/jdk1.8.0_211/jre/lib/ext/jfxrt.jar

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in eclipse environment: add jfxrt.jar to Bundle-ClassPath in MANIFEST.MF file.

Bundle-ClassPath: ., jfxrt.jar
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More detail. C-

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