I have a Java Project with Spring Boot and JavaFX added through maven. The code compiles and even i can execute the fat jar without the JavaFX SDK in the computer. But when I try to execute it in IntelliJ it results in
Error: JavaFX runtime components are missing, and are required to run this application
I have seen this output in many questions and in most of those cases the jar wasn't built at all or code compilation failed.
But in this scenario the mvn package works with no errors and I can execute the JAR with java -jar <jar_name> to cross out the fact that I might have the javafx sdk installed somewhere I tried it in a VM with only the JRE installed.
pom.xml
<dependency>
<groupId>org.openjfx</groupId>
<artifactId>javafx-controls</artifactId>
<version>11.0.2</version>
</dependency>
<dependency>
<groupId>org.openjfx</groupId>
<artifactId>javafx-fxml</artifactId>
<version>11.0.2</version>
</dependency>
As for plugins spring-boot-maven-plugin and maven-compiler-plugin.
Attempted Solutions
--1--
I tried the solution which said to add the
<plugin>
<groupId>org.openjfx</groupId>
<artifactId>javafx-maven-plugin</artifactId>
<version>0.0.6</version>
<executions>
<execution>
<id>default-cli</id>
<configuration>
<mainClass>com.example.demofx.Starter</mainClass>
</configuration>
</execution>
</executions>
</plugin>
But what it does is add the ability to run with: mvn clean javafx:run
The need to execute with IntelliJ is to debug the code because Debugging with souts isn't efficient.
--2--
Trying to module build with a module-info.jar with following
module com.example.demofx {
requires javafx.controls;
requires javafx.fxml;
// all other required modules including spring
opens com.example.demofx to javafx.fxml;
exports com.example.demofx;
}
This might have worked but due to some of old dependencies not working properly with modularized build this results in lots of breaking changes to the codebase.
Edit:
Missed to mention the environment
JDK - 11.0.8
IntelliJ IDEA - 2021.2.2
Added second solution tried.
This is more a troubleshooting and research guide than an actual fix. Fixes for environmental issues are difficult to provide in a StackOverflow context. However, if you study the information here, it might help you fix your project.
Recommended troubleshooting approach
Use the Intellij new JavaFX project wizard. Ensure that it works in your environment, then gradually add components from your current project into the working project, checking that everything still works after each small addition.
Debugging when executing via the JavaFX maven plugin
I think the above recommendation is the preferred approach, however, you can alternately get the following to work:
run with: mvn clean javafx:run
The need to execute with IntelliJ is to debug the code"
See:
intellij idea : how to debug a java:fx maven project?
I also think you can just right-click on the maven target for javafx:run and select Debug. I am not sure, I don't make use of the JavaFX maven plugin.
Creating fat jars for JavaFX applications
the fat jar
This is not a recommended configuration, but if you really must do it, you can review:
Maven Shade JavaFX runtime components are missing
That answer doesn't discuss getting such a configuration to work in conjunction with an Idea run/debug configuration, so it may not assist you.
If you do continue with a fat jar, I would not advise using a module-info, as you will be running code off the classpath anyway.
Modular versus non-modular JavaFX applications
If you don't use a fat jar, getting all the module dependencies correct for Spring is tricky anyway because Spring is not currently architected to directly support modules well. Spring 6 will be designed to work well with modules, though I think you should be able to get Spring 5 to work if you try hard enough (I have got it to work in the past for some applications).
Alternately you can just have the JavaFX components as modules and run the rest off the classpath. For example, the "Non-modular with Maven" approach at openjfx.io. Note that in that approach, the JDK and JavaFX modules are still loaded as modules off of the module path, it is only Spring your application that is not providing a module-info.java file and running off the classpath.
Creating runtime images for JavaFX applications
I also advise studying:
these resources for the creation of an appropriate runtime image.
I have troubles with importing classes from an existing Spring-Boot application into my new application after they changed the structure of the build jar file.
They changed the jar-file so that the applications own classes now are located in BOOT-INF/classes and not on the root of the jar-file.
But when I have a normal maven dependency to this Spring-boot application I can not import the existing classes from this application and into my new classes in my new application.
It worked just fine before they changed the structure...
The solution here is to refactor your code, so that the classes you're depending on in both your applications are available in a separate project.
Now you can use these classes by importing the dependency in both your projects:
<dependency>
<groupId>org.example</groupId>
<artifactId>example-shared</artifactId>
</dependency>
Make sure that you're not using the Spring boot maven plugin in this newly made shared project and you should probably not use any Spring boot starters either, since they load a lot of dependencies you may not need.
I found out that it is actually possible to use a Spring Boot application as a dependency. Even though it most likely is not recommended. But in some cases it just makes it easier.
This solution means that you can not use the executable archive.
"The executable archive cannot be used as a dependency as the executable jar format packages application classes in BOOT-INF/classes. This means that they cannot be found when the executable jar is used as a dependency."
The solution to my question is to include a configuration classifier to the spring-boot-maven-plugin. Like this for Maven:
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<classifier>exec</classifier>
</configuration>
</plugin>
or like this for Gradle:
bootRepackage {
classifier = 'exec'
}
I have a program which runs as a Spring boot App in eclipse. The program was running fine. Then i did the following:
Right click on project -> Run As -> Maven Test .
This was accidental. When i then tried to run the program as a spring boot app again, it threw the following error below.
Error: Could not find or load main class com.bt.collab.alu.api.webapp.Application
How do i point the application back to my main class?
Thanks
I had the same problem. Try this :
Right Click the project -> Maven -> Update Project
Then Re-run the project. Hope it work for you too.
Main class is configurable in pom.xml
<properties>
<start-class>com.bt.collab.alu.api.webapp.Application</start-class>
</properties>
Have a look under "Run -> Run Configurations..." in Eclipse. You should delete the new one which you created by mistake, you should still have the existing one.
I suspect it has created a new run configuration for the "Run as Maven Test" and you are now always starting this one.
If you're using Spring Boot and the above suggestions don't work, you might want to look at the Eclipse Problems view (available at Window -> Show View -> Problems).
For example, you can get the same error (Error: Could not find or load main class groupId.Application) if one of your jar files is corrupted. Eclipse will complain that it can't find the Applications class, even though the bad jar is the root cause.
The Problems view, however, will identify the bad jar for you.
At any rate, I had to manually go to my local mvn repo (in .m2) and manually delete the corrupted jar, and update it (right click on the project in the Package Explorer), Maven --> Update Project... -> OK (assuming that the correct project is check-marked).
I tried all the above solution, but didn't worked for me.
Finally was able to resolve it with a simple fix.
on STS,
Run Configuration > open your Spring Boot App > Open your configuration,
Follow the steps,
In Spring boot Tab, check your Main class and profile.
Then go to classpath tab, In the bottom you will see two checkboxes,one is "Exclude Test Code"(Check this if you do not want to run test classes) and other, "Use Temporary Jar file to specify classpath" (this is necessary).
Save your configuration and run.
This happened to me after i updated the pom (Added some dependencies).
The following step helped me to avoid this error
right click on the project > maven > update project
Intellij
close Intellij
remove all files related to Intellij (.idea folder and *.iml files)
open the project in Intellij as if it was the first time (using open recent won't work, id needs to be done via file -> open)
Use spring-boot:run command to start spring boot application:
Precondition:
1. Add following property to pom.xml
<property>
<start-class>com.package.name.YourApplicationMainClass</start-class>
</property>
2. Build your project
Then configure maven command with spring-boot:run.
Navigation:
Right Click Project | Run As | Run Configuration... | Add new Maven Configuration with command spring-boot:run
In case if someone is using Gradle for the build then fix will be by adding the following lines in build.gradle file
apply plugin: 'application'
mainClassName = "com.example.demo.DemoApplication"
The solution for me was:
Boot Dashboard, right click on your Instance.
Open Config
Tab Spring Boot
Main Type, there was the path to the application file missing...
I know this is pretty late answer. But it might still help some new learners.
The Following example is only for springboot with NETBEANS.
I had to do the following steps:
Step 1. Follow #Mariuszs answer .
Step 2. Right click on project -> Properties -> RUN.
Make sure the Main Class field is has the correct starter class else Click browse and select from the available classes .
Step 3. Click OK-> OK. Thant is all. Thank you.
I have used spring 1.5.3.RELEASE version and given pom dependencies like
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.3.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
And my main class was
#SpringBootApplication
public class SpringAppStarter {
public static void main(String[] args) {
SpringApplication.run(SpringAppStarter.class, args);
}
}
But still while execution of main class I was getting:
Could not find or load main class ... with my class name.
I could see that class was available in the class path and I was using STS IDE.
I was not getting reason for the issue then I tried manual build through maven with
mvn clean install
Still problem was there then i realize that my project has two libraries
Reference Library
Maven Library
What I did:
I have created another mavenRepo folder and build it again and refresh my project. After that it worked and I saw that Maven Library was deleted from project class path.
Issues was while execution it was getting multiple version so it was not able to find proper class to execute my application.
Other Solution listed in this page also resolves the issue but if you are doing mistake in
Annotating class
pom entry
jar version etc.
Hope this may resolve problem if somebody get this issue
deleting old jars from .m2 and updating maven project should be primary step.
In most of the cases it resolves the issue.The reason for this issue is mostly corrupted old jars
Encountered the same issue and was able to fix it by the following the steps listed below:
File -> Invalidate Cache and Restart
File -> New -> Project from existing source
Select the pom.xml file just (not the whole project directory) to load the project. Project will be setup automatically.
Error:Could not load or find main class
Project:Spring Boot
Tool:STS
Resolve Steps:
Run the project
See in problems tab, it will show the corrupted error
Delete that particular jar(corrupted jar) in .m2 folder
Update project
Run successfully
I was having the same problem just delete .m2 folder folder from your local repositry
Hope it will work.
start-class doesn't work for me, I fixed it by adding build plugins to pom.xml, and executions is necessary.
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
There are good answers here, but maybe this one will also help somebody.
For me it happened just after i deleted .idea (with IntelliJ), and reimported the project.
then this issue started, i tried to run mvn compile (just via IDE Maven toolbar), once i fixed few compilation errors, issue disappeared
If you came across the
error:could not find or load main class in maven project
do this it worked for me:
Reason for the error: The reason for this error is the jar file or dependency to run a maven project is not installed correctly.
Solution for the error: Go to the project folder (eg: D:\office\OIA-service-app)
in the address bar of computer type command cmd and press enter.
In the command prompt type command mvn clean install make sure you have the internet connection.
If your project packaging type war you could not start. I was using maven assembly plugin with this configuration;
<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.0.0</version><!--$NO-MVN-MAN-VER$ -->
<configuration>
<descriptors>
<descriptor>assembly.xml</descriptor>
</descriptors>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<mainClass>com.ttech.VideoUploaderApplication</mainClass>
</manifest>
</archive>
</configuration>
<executions>
<execution>
<id>make-assembly</id> <!-- this is used for inheritance merges -->
<phase>package</phase> <!-- bind to the packaging phase -->
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
and my packaging tpe was war i got cannot find main class exception bu i changed packaging to jar it worked;
<groupId>com.ttect</groupId>
<artifactId>VideoUploadListener</artifactId>
<version>1.0.0</version>
<packaging>**jar**</packaging>
In my case the following helped:
Added the following section in pom
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<executable>true</executable>
</configuration>
</plugin>
</plugins>
Ran it using maven3 and it worked
I also got this error, was not having any clue. I could see the class and jars in Target folder. I later installed Maven 3.5, switched my local repo from C drive to other drive through conf/settings.xml of Maven. It worked perfectly fine after that. I think having local repo in C drive was main issue. Even though repo was having full access.
I was facing the same problem. I have deleted the target folder and run maven install, it worked.
I had similar kind of problem while I was adding spring security dependency to my project ,
then I deleted my target folder and used maven update again .
It's worked for me.
Even I faced the same issue, later I found that it happened because the maven build operation was not happening properly in my environment. Please check it in your case also.
I ran into same error, although i was using gradle build. Delegating IDE build/run actions to Gradle is solved my problem.
Intellij:
Settings -> Build, Execution, Deployment -> Build Tools -> Gradle -> Runner
I got the same error in the "Spring Tool Suite" software.
In my case, I have Java 8 installed and I created a project of Java 11. And when I run the project I got the same error, like " can not find main class ".
Then I created a project in Java 8 and the problem resolved.
(Eclipse) Updating maven project was not working for me. What I had to do was to go in Run configurations, and in "Main" tab, in "Project" field, write the whole package name com.bla.blabla.MyMainClass (instead of just the Main class name).
The error happened because I have several projects with the same name, but in different packages.
if none of above solutions work, try to replace build tag with this inside pom file :
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins></pluginManagement>
</build>
I am new in spring boot and using STS with maven build. I did all the things mentioned above but won't work for me. I noticed two problems in problem window of STS. There was a missing jar file on the path (C:\Users\UserName.m2\repository\com\jayway\jsonpath\json-path\2.2.0). I did following, the way is not strongly suggested but worked for me.
1) I deleted .m2 folder from the path location
2) Restarted STS
3) Right Click on project folder -> maven -> update project -> checked "Force update of snapshots/releases" -> Click Ok.
Maven updated its dependencies and the problem is solved.
I know that typically maven structure is like this:
pom.xml
src
- main
- web
- WEB-INF
However, I have a project which has the following structure
src
- main
web
- WEB-INF
The latter of the two above currently does not use maven. I've started using maven for this project locally by making the structure conform to the maven standard. However, I now want to automatically build this project from jenkins by getting it out of the source control (svn). So I would like to just add a pom.xml which is aware of the fact that web isn't inside src
Is this possible to do with maven?
You can configure the maven-war-plugin to use another warSourceDirectory but as Jeff Storey explains in his answer it is really not recommended.
This is how you would do it:
<project>
...
<build>
<plugins>
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>2.3</version>
<configuration>
<warSourceDirectory>web</warSourceDirectory>
</configuration>
</plugin>
</plugins>
</build>
...
</project>
One of several problems is for example that the maven-jetty-plugin will not run out-of-the-box. It will by default look in src/main/webapp so that has to be configured.
You might not use the maven-jetty-plugin but you get the idea.
Using the maven war plugin properties, you can set the warSourceDirectory property http://maven.apache.org/plugins/maven-war-plugin/war-mojo.html (I'm not sure exactly what problems you're having, so this may or may not solve your specific problem).
However, maven is very opinionated and I would strongly recommend using the expected maven structure. Other plugins may give you unexpected problems down the road, and maven life is generally a lot easier when you follow their conventions.