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Failed to parse plugin descriptor for org.web3j:core:5.0.0

I'm trying to add the web3j library ( version 5.0.0 ) into the generated .jar of a java project, but for some reason I keep getting the error :
Failed to parse plugin descriptor for org.web3j:core:5.0.0 (C:\Users\...\.m2\repository\org\web3j\core\5.0.0\core-5.0.0.jar): No plugin descriptor found at META-INF/maven/plugin.xml -> [Help 1]
( Tried different versions , same error )
The pom.xml file content is the following :
<?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>org.example</groupId>
<artifactId>BMarketMC-v2</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<properties>
<maven.compiler.source>8</maven.compiler.source>
<maven.compiler.target>8</maven.compiler.target>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
</properties>
<dependencies>
<dependency>
<groupId>org.spigotmc</groupId>
<artifactId>spigot-api</artifactId>
<version>1.16.4-R0.1-SNAPSHOT</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.web3j</groupId>
<artifactId>core</artifactId>
<version>4.8.4</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.web3j</groupId>
<artifactId>core</artifactId>
<version>5.0.0</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.spigotmc</groupId>
<artifactId>spigot-api</artifactId>
<version>1.16.4-R0.1-SNAPSHOT</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
This error occurs when I run the package operation of the lifecycle , e.g :
Where exactly should be this META-INF folder? Because it's not in the project directory.
Please some help, any idea how can I fix this?

I'm not sure how much is this gonna help but I've solved my problem by giving up on using maven and add it as jar to project modules.

How to run my maven project (angular+springboot) on tomcat?

I have created a web application based on angular 8 and spring boot. I implemented the codebase locally and it is working fine.
My Angular code(client) is running on localhost:4200 and spring boot(server) is running on localhost:8080.
Till here everything is working as expected.
Now I want to deploy this whole web application as a single bundle so that I can deploy it as a single war on tomcat.
I am creating the war file using maven.
But when I deploy this war file on tomcat and start the tomcat I am not able to see the expected login page on the browser.
Basically, I don't have much understanding of maven and was following resource available in below link on the internet to generate the war file.
https://dzone.com/articles/building-a-web-app-using-spring-boot-angular-6-and
So I am not able to figure out whether the issue is with my build or the URL through which I am trying to access the resources.
if I deploy only the UI build, then if I hit localhost:8080, I am able to see the login page.
I am having three pom files as mentioned in the tutorial.
1. parent-pom
2. server-pom
3. ui-pom
Below are my pom files
parent-pom.xml:
<?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>com.dzs.licenseGenerator</groupId>
<artifactId>lg-parent</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>pom</packaging>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.6.RELEASE</version>
<relativePath />
</parent>
<modules>
<module>LicenseGenerator_Backend</module>
<module>LicenseGenerator_UI</module>
</modules>
</project>
server-pom.xml
<?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>
<parent>
<groupId>com.dzs.licenseGenerator</groupId>
<artifactId>lg-parent</artifactId>
<version>0.0.1-SNAPSHOT</version>
<!-- lookup parent from repository -->
</parent>
<artifactId>LicenseGenerator_Backend</artifactId>
<packaging>war</packaging>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.dzs.licenseGenerator</groupId>
<artifactId>LicenseGenerator_UI</artifactId>
<version>${project.version}</version>
<scope>runtime</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<executions>
<execution>
<id>copy-resources</id>
<phase>validate</phase>
<goals><goal>copy-resources</goal></goals>
<configuration>
<tasks>
<echo>Displaying value of pom.xml element</echo>
<echo>[project.build.directory] ${project.build.directory}</echo>
<echo>[project.parent.basedir] ${project.parent.basedir}</echo>
</tasks>
<outputDirectory>${project.build.directory}/classes/resources/</outputDirectory >
<resources>
<resource>
<directory>${project.parent.basedir}/LicenseGenerator_UI/dist/lg-app/</directory >
</resource>
</resources>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-failsafe-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<configuration>
<packagingExcludes>WEB-INF/lib/tomcat-*.jar</packagingExcludes>
<warName>lg-app</warName>
</configuration>
</plugin>
</plugins>
</build>
</project>
UI-pom.xml
<?xml version="1.0"?>
<project
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.dzs.licenseGenerator</groupId>
<artifactId>lg-parent</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<artifactId>LicenseGenerator_UI</artifactId>
<name>LicenseGenerator_UI</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<build>
<plugins>
<plugin>
<groupId>com.github.eirslett</groupId>
<artifactId>frontend-maven-plugin</artifactId>
<version>1.4</version>
<configuration>
<nodeVersion>v10.16.0</nodeVersion>
<npmVersion>6.9.0</npmVersion>
<workingDirectory>src/main/web/</workingDirectory>
</configuration>
<executions>
<execution>
<id>install node and npm</id>
<goals>
<goal>install-node-and-npm</goal>
</goals>
</execution>
<execution>
<id>npm install</id>
<goals>
<goal>npm</goal>
</goals>
</execution>
<execution>
<id>npm run build</id>
<goals>
<goal>npm</goal>
</goals>
<configuration>
<arguments>run build</arguments>
</configuration>
</execution>
<execution>
<id>prod</id>
<goals>
<goal>npm</goal>
</goals>
<configuration>
<arguments>run-script build</arguments>
</configuration>
<phase>generate-resources</phase>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
Just to ensure whether my code structure is correct or not I am posting a screenshot of my Project Explorer in Eclipse.

Use ng build –prod command for generating production build artifacts.
Run this command in your UI project folder.
Post generation of production build you should see new folder named ‘dist’.
You have to use Maven resource plugin to package as single jar. As i can see you already have the plugin in you pom, just verify the directory folder to pint to dist folder.
After this just run maven clean install . After running this you should see jar with both Angular 6 & Spring Boot application on the target folder.
Execute with Java –jar command to launch the application, you should see the Angular application served from static folder.

You can use frontend-maven-plugin for kicking off your frontend build. Once the frontend build is completed, it will generate the resource files in dist directory.
After that you can use the maven-resources-plugin to copy the files from dist to the required location in the target directory.

java.lang.NoClassDefFoundError while finding class in package

I have project (TeamCity plugin), written in Scala, packaged by maven and running on TeamCity(which uses Spring).
There is the dependency com.ullink.slack.simpleslackapi in my project. Now I try to update it (from 0.5.2 to 1.2.0) and become an error at runtime.
Error java.lang.NoClassDefFoundError: Could not initialize class
com.ullink.slack.simpleslackapi.impl.SlackWebSocketSessionImpl
The code that caused this exception is pretty simple:
val session = SlackSessionFactory.createWebSocketSlackSession(config.oauthKey)
My build/pom.xml file looks like
<?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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<artifactId>***</artifactId>
<groupId>***</groupId>
<version>1.0.0</version>
</parent>
<artifactId>build</artifactId>
<packaging>pom</packaging>
<dependencies>
<dependency>
<groupId>***</groupId>
<artifactId>***-server</artifactId>
<version>1.0.0</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.1.0</version>
<executions>
<execution>
<id>make-assembly</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
<configuration>
<finalName>***</finalName>
<outputDirectory>${project.parent.build.directory}</outputDirectory>
<appendAssemblyId>false</appendAssemblyId>
<descriptors>
<descriptor>plugin-assembly.xml</descriptor>
</descriptors>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
I've tried to append this dependency to this file and tried maven-shade-plugin — it does not help.
Could you advice what else can I try?

maven assembly plugin does not include my classes inside built jar

Any code referenced below is from the project here
For the AWS Lambda, I have been trying to create a jar file based on the maven configuration defined here.
<?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>be.quodlibet</groupId>
<artifactId>HelloLambda</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>com.amazonaws</groupId>
<artifactId>aws-lambda-java-core</artifactId>
<version>1.1.0</version>
</dependency>
<dependency>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.1.0</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.1.0</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>assemble-all</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
When I try and build the fat JAR, upload it to AWS Lambda console, I see the error
The following package be.quodlibet.hellolambda was not added to the jar resulting in a
"errorMessage": "Class not found: be.quodlibet.hellolambda.helloHandler",
"errorType": "java.lang.ClassNotFoundException"

As #khmarbaise said in the comments, make sure you run "mvn clean package" and not "mvn clean assembly:single".

How to tell the maven-shade-plugin to preserve signatures?

I am using the maven-shade-plugin to combine two seperate jars into a single combined jar.
One of the jars is signed, while the other is not.
If I use the default configuration of the plugin, it will build a broken jar as the new manifest is missing the digest needed by the signature.
I could "fix" the jar by excluding the signature files, but this will of course result in a completely unsigned jar.
I am looking for a way to create a combined jar with all the signed classes remaining signed and valid. - The jar format allows those kind of jars but I could not find an easy way to tell the shade plugin to do so.
Should I write my own transformer to do a proper merging of manifest files or is there already a suitable option in the shade-plugin I did not find, yet?
Example:
pom.xml (defining two modules "foo" and "bar")
<?xml version="1.0"?>
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>mygroup</groupId>
<artifactId>myparent</artifactId>
<packaging>pom</packaging>
<version>1.0</version>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<modules>
<module>foo</module>
<module>bar</module>
</modules>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.4</version>
<configuration>
<archive>
<addMavenDescriptor>false</addMavenDescriptor>
</archive>
</configuration>
</plugin>
</plugins>
</build>
</project>
foo/pom.xml: (combine signed bar into unsigned foo)
<?xml version="1.0"?>
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>mygroup</groupId>
<artifactId>myparent</artifactId>
<version>1.0</version>
</parent>
<artifactId>foo</artifactId>
<dependencies>
<dependency>
<groupId>mygroup</groupId>
<artifactId>bar</artifactId>
<version>1.0</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>2.3</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<transformers>
<transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
<manifestEntries>
<Main-Class>Foo</Main-Class>
</manifestEntries>
</transformer>
</transformers>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
bar/pom.xml: (create signed bar)
<?xml version="1.0"?>
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>mygroup</groupId>
<artifactId>myparent</artifactId>
<version>1.0</version>
</parent>
<artifactId>bar</artifactId>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jarsigner-plugin</artifactId>
<version>1.3.2</version>
<configuration>
<keystore>${user.home}/keystore-name</keystore>
<alias>alias-name</alias>
<storepass>123456</storepass>
</configuration>
<executions>
<execution>
<id>sign</id>
<goals>
<goal>sign</goal>
</goals>
</execution>
<execution>
<id>verify</id>
<goals>
<goal>verify</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
If both modules contain a single hello-word class, I would expect java -jar foo/target/foo-1.0.jar to work and jarsigner -verify foo/target/foo-1.0.jar to tell about the presence of signed classes.

The maven shade plugin does not play nicely with signed jars. I would recommend you take a look at Capsule that is way better to do this kind of job.