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java maven class not found exception

I built a server template in java and now i need to compile and run it using MAVEN.
this is my POM:
<?xml version="1.0" encoding="UTF-8"?>
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0">
<modelVersion>4.0.0</modelVersion>
<groupId>bgu.spl</groupId>
<artifactId>spl-net</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
-<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<name>spl-net</name>
</project
When I run mvn compile it all works. but then i go to test it with: mvn exec:java - Dexec.mainClass=”bgu.spl.net.impl.BGRSServer.ReactorMain” - Dexec.args=”<port> <No of threads>” and it gives me a class not found exception. I looked in the target directory and this exact main was indeed there, it just refuses to run.

Turns out there was nothing wrong with my code. I failed to realize that in ubuntu, the command: mvn exec:java - Dexec.mainClass=”bgu.spl.net.impl.BGRSServer.ReactorMain” - Dexec.args=”<port> <No of threads>” simply doesn't work. the correct command would be: mvn exec:java - Dexec.mainClass=bgu.spl.net.impl.BGRSServer.ReactorMain - Dexec.args=<port> <No of threads>

JavaFX11 and Intellij

I followed the instruction in this link
https://openjfx.io/openjfx-docs/#install-javafx
and when i run javafx sample i get this error
Error:(3, 26) java: cannot access javafx.application.Application
bad class file: C:\Program Files\Java\OpenJDK\javafx-sdk-11.0.1\lib\javafx.graphics.jar(javafx/application/Application.class)
class file has wrong version 54.0, should be 52.0
Please remove or make sure it appears in the correct subdirectory of the classpath.
and when i go to Project Structure > Project/Modules the JDK is set to JDK11
VM option:
--module-path C:\Program Files\Java\OpenJDK\javafx-sdk-11.0.1\lib --add-modules=javafx.controls,javafx.fxml
I tried to go to Settings > Build, Execution, Deployment > Compiler > Java Compiler
Project bytecode version was set to 8 and i changed it to 11 and the first error was gone but i got new error
Error:java: invalid target release: 11
I was searching on the internet and somebody said go to .idea\compiler.xml and set target to 11 but it's already set to 11 for me but i get the error

Go To File > Project Structure > Modules > Source
Set Language Level to 11 (if 11 not Available set to "X-Experimental Features")
Image

I have just encountered the error, could not find proper solution either, so I figured out myself.
Problem location: pom.xml - maven file
Sometimes issue can happen with different JavaFX entity, for instance with FXMLLoader or EventHandler:
java: cannot access javafx.fxml.FXMLLoader bad class file: ... class file has wrong version 55.0, should be 53.0
java: cannot access javafx.event.EventHandler bad class file: /Users/john/.m2/repository/org/openjfx/javafx-base/12/javafx-base-12-mac.jar!/javafx/event/EventHandler.class class file has wrong version 55.0, should be 53.0
Fixed version of pom.xml file:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>hkr</groupId>
<artifactId>CommunicationTest</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<maven.compiler.source>9</maven.compiler.source>
<maven.compiler.target>9</maven.compiler.target>
</properties>
Incorrect (previous verison):
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>hkr</groupId>
<artifactId>CommunicationTest</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
The issue is in properties tag, the target version was below JDK version (9.0.1), which was causing in my case a problem of "class file has wrong version 55.0, should be 53.0".
I simply changed to target 9 instead of 1.8 and it got fixed.

Dependency error in eclipse project making use of Maven

I am using Eclipse Mars to run my Java project. I am making use of Maven in it. But while trying to compile my package I am getting the following error.
Failed to execute goal on project apex-check: Could not resolve dependencies for project org.fundacionjala.enforce.sonarqube:apex-check:jar:1.0: Failed to collect dependencies at org.fundacionjala.enforce.sonarqube:apex-squid:jar:1.0: Failed to read artifact descriptor for org.fundacionjala.enforce.sonarqube:apex-squid:jar:1.0: Could not transfer artifact org.fundacionjala.enforce.sonarqube:apex-squid:pom:1.0 from/to central (https://repo.maven.apache.org/maven2): Failed to authenticate with proxy -> [Help 1].
I am able to find that my pom.xml has a bug in its dependency. But don't know how to resolve it. I have given below my pom.xml file
<?xml version="1.0" encoding="UTF-8"?>
<!-- ~ Copyright (c) Fundacion Jala. All rights reserved. ~ Licensed under the MIT license. See LICENSE file in the project root for full license information. -->
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.fundacionjala.enforce.sonarqube</groupId>
<artifactId>apex</artifactId>
<version>1.0b${build.number}</version>
</parent>
<artifactId>apex-check</artifactId>
<name>Apex :: Checks</name>
<dependencies>
<dependency>
<groupId>${project.groupId}</groupId>
<artifactId>apex-squid</artifactId>
<version>${project.version}</version>
</dependency>
</dependencies>
</project>
I have written 'apex-check' and 'apex-squid' as two separate projects.
Can anyone explain how to correct my pom.xml?

You need to have:
org.fundacionjala.enforce.sonarqube:apex-check:jar:1.0
org.fundacionjala.enforce.sonarqube:apex-squid:jar:1.0
jar files available in your local .m2/repository folder. If they are not present maven will try to download from central repository and as an expected result it will fail on firewall or it will not find the artifact. i.e. if:
apex-check requires apex-squid project as dependency first you need to install squid project files by using mvn install on squid project folder.
But it seems more like you want to create a multi module maven project, take a look at this question. Create a parent project similar to this project, add check and squid as module and run mvn clean install on parent.
**edit: I just see you already have parent, so make sure parent has your projects as modules, which helps reactive build order and eclipse imports

Exception in thread "main" java.lang.UnsatisfiedLinkError: Cannot find TensorFlow native library for OS: linux, architecture: x86_64

I am trying setup TensorFlow Java application in Eclipse Oxygen (OS: Ubuntu Linux 16.x). I installed Tensorflow and followed the process mentioned in official documentation for Java (Maven Project) installation. I downloaded libtensorflow-1.3.0.jar, jni files and included in the build path. When I execute the program I get this following error
Exception in thread "main" java.lang.UnsatisfiedLinkError: Cannot find TensorFlow native library for OS: linux, architecture: x86_64. See https://github.com/tensorflow/tensorflow/tree/master/tensorflow/java/README.md for possible solutions (such as building the library from source). Additional information on attempts to find the native library can be obtained by adding org.tensorflow.NativeLibrary.DEBUG=1 to the system properties of the JVM.
at org.tensorflow.NativeLibrary.load(NativeLibrary.java:66)
at org.tensorflow.TensorFlow.init(TensorFlow.java:36)
at org.tensorflow.TensorFlow.<clinit>(TensorFlow.java:40)
at com.tensorflow.malwaredetection.App.main(App.java:13)
App.java
package com.tensorflow.malwaredetection;
import org.tensorflow.TensorFlow;
/**
* Hello world!
*
*/
public class App
{
public static void main( String[] args )
{
System.out.println( "Hello World!"+ TensorFlow.version() );
}
}
POM.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>TensorFlow</groupId>
<artifactId>MalwareDetection</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>MalwareDetection</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<exec.mainClass>App</exec.mainClass>
<!-- The sample code requires at least JDK 1.7. -->
<!-- The maven compiler plugin defaults to a lower version -->
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.tensorflow</groupId>
<artifactId>libtensorflow</artifactId>
<version>1.3.0</version>
</dependency>
</dependencies>
</project>
I got tired of this error and tried to do this in an old-fashioned way. Created App.java in a separate folder and included jar, jni files in the same directory. When I execute this from command line, I get different error
dev#ubuntu:~/Downloads$ javac -cp libtensorflow-1.3.0.jar Test1.java
dev#ubuntu:~/Downloads$ java -cp libtensorflow-1.3.0.jar:. -Djava.library.path=./jni Test1
Error: Could not find or load main class Test1
dev#ubuntu:~/Downloads$

I think you need to include jni library dependency in your pom.
<dependency>
<groupId>org.tensorflow</groupId>
<artifactId>libtensorflow_jni</artifactId>
<version>1.1.0</version>
</dependency>

When you have tensor flow dependency in your pom.xml file as below
<dependencies>
<dependency>
<groupId>org.tensorflow</groupId>
<artifactId>tensorflow</artifactId>
<version>1.14.0</version>
</dependency>
It will download required 3 libraries
tensorflow-1.14.0.jar
libtensorflow-1.14.0.jar
libtensorflow_jni-1.14.0.jar
So you have to manually extract the 3rd jar(libtensorflow_jni) and get your OS compatible file like for windows you have to copy the tensorflow_jni.dll file and paste in your project root directory
that will solve your problem.

For Linking error the JNI library which you have downloaded is
not compatible with OS you are running,
is not in PATH () or
with lesser probability TensorFlow bu which you should be able to confirm from TF triage.
For second could not find class
your PATH must be appended with "." so that it can find class in current folder from where it is running
Less probability is if class name/package is not same.
If you can post code for class will check

How to download source code from Maven Central for a project

I want to download the source code for the project XBee-api v9.3 from Maven Central so that I can modify the code for my application. I am using Netbeans and I have managed to produce a POM that validates and compiles successfully.
I have then run the command
mvn dependency:resources
from the same directory as the POM to force download of the source code.
I have a few problems:
When I look inside the project with Netbeans, I see the class files (which I think may actually be jars). When I open up any class, I only get the method headers, but not the source code.
When I open a class file, there is the option in the top right of the window to "Attach Sources...". When I select "Download", I get a message in the lower left of the window saying "Downloading source jar from known Maven Repositories for local repository file" but nothing seems to be happening.
When I open up the folder either with explorer or Netbeans files view, the folder is empty except for the POM. If I use Projects view in Netbeans, I can see a project structure and what appears to be the generated source files, but no source code.
I can't find answers on Google.
My questions are:
What am I doing wrong?
How do I download the source code?
Any help would be much appreciated.
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.rapplogic</groupId>
<artifactId>xbee-api</artifactId>
<packaging>jar</packaging>
<version>0.9.3</version>
<name>${project.groupId}:${project.artifactId}</name>
<description>A java library for communicating with XBee radios</description>
<url>https://github.com/andrewrapp/xbee-api/</url>
<licenses>
<license>
<name>GPL license, Version 3.0</name>
<url>https://www.gnu.org/licenses/gpl-3.0.html</url>
</license>
</licenses>
<developers>
<developer>
<name>Andrew Rapp</name>
<email>andrew.rapp+github.com#gmail.com</email>
</developer>
</developers>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.6</maven.compiler.source>
<maven.compiler.target>1.6</maven.compiler.target>
</properties>
<!-- https://mvnrepository.com/artifact/com.rapplogic/xbee-api -->
<dependencies>
<dependency>
<groupId>com.rapplogic</groupId>
<artifactId>xbee-api</artifactId>
<version>0.9.3</version>
</dependency>
</dependencies>
</project>

The GitHub project page is here:
https://github.com/andrewrapp/xbee-api
(referenced in the POM under the url element)
...so you can just download the source from the Github page: https://github.com/andrewrapp/xbee-api/archive/master.zip