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maven dependency not properly compile into war

I am using the Eclipse IDE and in the past, I have been developing a maven project depending on local sources (from github (sap-olingo)) as well as maven dependencies loaded as jar. I have now updated the github source and also all the dependencies which seems to break standard eclipse export functionalities (right click porject -> export -> war)
The webproject is working fine when using the maven install functionality and is loading all sources into the META-INF/lib classes, but when using the export as war from eclipse (which I did previously) it is missing to compile a proper dependency. Missing in the sense of that the jar is still present in the META-INF/lib directory of the war, but the content is empty and the size is only 1kb
When comparing the mvn clean install to the exported, there are rarely any differences. Except for the projects that are to be compiled during the runtime. Sizes of the libs in the mvn created war and the exported war roughly matches except for that one jar.
Is there a way to root cause that issue? I am using solely the maven integrated into the IDE which is why I doubt differences in the maven versions and or jdk.
Unfortunately I have no idea in where to start and what info you require
Thanks for your input
EDIT:
My projects pom:
<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>com.test</groupId>
<artifactId>odata</artifactId>
<packaging>war</packaging>
<version>4.0.0</version>
<name>odataMaven Webapp</name>
<url></url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.sap.olingo</groupId>
<artifactId>odata-jpa-processor</artifactId>
<version>0.3.7-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>com.microsoft.sqlserver</groupId>
<artifactId>mssql-jdbc</artifactId>
<version>6.1.0.jre8</version>
</dependency>
<dependency>
<groupId>org.eclipse.persistence</groupId>
<artifactId>javax.persistence</artifactId>
<version>2.1.0</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.eclipse.persistence</groupId>
<artifactId>eclipselink</artifactId>
<version>2.6.2</version>
</dependency>
</dependencies>
<build>
<finalName>odata</finalName>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.17</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>${project.build.source}</source>
<target>${project.build.source}</target>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.build.source>1.8</project.build.source>
</properties>
</project>
The odata-jpa-processor source/project is pulled from here. The problem exists solely with the olingo-jpa-metadata jar which is empty. All other maven dependencies are exported correctly.

Maven pom file, what is it doing?

I have just started using Maven, in a newbie capacity, just want to understand something around dependencies.
I am trying to build a micro web service using iText and the pdf output functionality.
So my very first steps is seeing if I can get a pdf output from a very simple Java program.
In my pom file i have the following dependencies:
<!-- iText Core -->
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>itext7-core</artifactId>
<version>${itext.version}</version>
<type>pom</type>
</dependency>
<!-- iText pdfHTML add-on -->
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>html2pdf</artifactId>
<version>2.1.6</version>
</dependency>
After reading the information on the Maven site, the pom file should do all of the heavy lifting in getting the dependencies, this is the bit i'm a little confused on.
Will the pom file physically download the files to the the app location on application start so that he app can utilize these files?
if that's the case it doesn't seem to be doing this and so am I missing something in the pom file to enable this?
The full pom file is:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.mycompany.app</groupId>
<artifactId>my-app</artifactId>
<version>1.0-SNAPSHOT</version>
<name>my-app</name>
<!-- FIXME change it to the project's website -->
<url>http://www.example.com</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
<itext.version>RELEASE</itext.version>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
<!-- iText Core -->
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>itext7-core</artifactId>
<version>${itext.version}</version>
<type>pom</type>
</dependency>
<!-- iText pdfHTML add-on -->
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>html2pdf</artifactId>
<version>2.1.6</version>
</dependency>
</dependencies>
<build>
<pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
<plugins>
<!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
<plugin>
<artifactId>maven-clean-plugin</artifactId>
<version>3.1.0</version>
</plugin>
<!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.22.1</version>
</plugin>
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-install-plugin</artifactId>
<version>2.5.2</version>
</plugin>
<plugin>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.8.2</version>
</plugin>
<!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
<plugin>
<artifactId>maven-site-plugin</artifactId>
<version>3.7.1</version>
</plugin>
<plugin>
<artifactId>maven-project-info-reports-plugin</artifactId>
<version>3.0.0</version>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
Any help appreciated.
Thanks

When maven build is executed, Maven automatically downloads all the dependency jars into the local repository.
the local repository of Maven is a folder location on the developer's machine, where all the project artifacts are stored locally.
Usually this folder is named .m2.
Here's where the default path to this folder is – based on OS:
Windows: C:\Users\User_Name\ .m2
Linux: /home/User_Name/.m2
Mac: /Users/user_name/.m2
https://www.baeldung.com/maven-local-repository

Maven does download the dependencies to the local m2 repository. But this is more meant for building the application, not for running.
What you want (copy the dependencies next to the output jar) can be achieved with the goal dependency:copy-dependencies
See this blog post:
https://technology.amis.nl/2017/02/09/download-all-directly-and-indirectly-required-jar-files-using-maven-install-dependencycopy-dependencies/

Managing dependencies is one of the key features of Maven.
Dependency management: It is possible to define dependencies to other
projects. During the build, the Maven build system resolves the
dependencies and it also builds the dependent projects if needed.
Resolving dependencies does mean it downloads all the specified jars in the local system.
The Maven tooling reads the pom file and resolves the dependencies of
the project. Maven validates if required components are available in a
local repository. The local repository is found in the .m2/repository
folder of the users home directory.
Note that .m2/ is a hidden folder. If you are using Linux, would be this path /home/someuser/.m2
Read this
If however its not downloading the jars or creating the .m2 directory at all, then either you are not building the project right or you are not connected to the internet.

Why does "WEB-INF/lib" folder appear to be empty after a Maven project is built within Eclipse?

i followed this spring-mvc-tutorial using eclipse, but after i call Maven / Update Projects my WEB-INF/lib directory remains empty.
this is how my project explorer looks:
i also see no mistake in my Deployment Assembly settings:
this is the pom.xml file i use:
<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>CrunchifySpringMVCTutorial</groupId>
<artifactId>CrunchifySpringMVCTutorial</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.2</version>
</dependency>
</dependencies>
<build>
<sourceDirectory>src</sourceDirectory>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>2.4</version>
<configuration>
<warSourceDirectory>WebContent</warSourceDirectory>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
</plugins>
</build>
i even switched to a new workspace as suggested in this link, but nothing helped
EDIT:
when i start the server i get the error:
java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet

Eclipse virtually hides the files from the view that displays the WEB-INF/lib folder in a Maven-managed Dynamic Web-Project project. As your first screenshot indicates, the "Maven Dependencies" library entry has been successfully added to your classpath in the background by Eclipse - it contains every dependency referenced in your pom.xml.
The intention behind this behavior for that is/might be: You - as a developer - are not supposed to copy any .jar files manually to WEB-INF/lib, cause that way you would kind of cheat around the idea behind a (Maven-) managed project.
In a certain way, this makes sense as Maven performs any dependency management for you and thus resolves and "bundles" any third-party (or your own) artifacts.
If you run a mvn with the goals clean package (or even: clean install) it will produce a .war file for you in the "target" folder of your project. If you extract that .war file you should find a WEB-INF/lib folder that contains all dependencies bundled into your deployable artifact.

I think it is correct.
Libraries are copied into target after build, not into project itself.
Also Step 8 in the tutorial you pasted shows the same (empty lib folder)

Tomcat Jersey Eclipse ClassNotFound org.glassfish.jersey.servlet.ServletContainer

I am running the hello world example.
However, I am using version 2.7.
on maven pom.xml I have
<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.mydomain.restful</groupId>
<artifactId>AdvertServer</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>Advert Server</name>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.glassfish.jersey</groupId>
<artifactId>jersey-bom</artifactId>
<version>2.7</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.2.4</version>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-web-api</artifactId>
<version>6.0</version>
</dependency>
<dependency>
<groupId>javax.ws.rs</groupId>
<artifactId>javax.ws.rs-api</artifactId>
<version>2.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.core</groupId>
<artifactId>jersey-client</artifactId>
<version>2.7</version>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.containers</groupId>
<artifactId>jersey-container-servlet-core</artifactId>
<version>2.7</version>
<!-- use the following artifactId if you don't need servlet 2.x compatibility -->
<!-- artifactId>jersey-container-servlet</artifactId -->
</dependency>
</dependencies>
<build>
<sourceDirectory>src</sourceDirectory>
<resources>
<resource>
<directory>src</directory>
<excludes>
<exclude>**/*.java</exclude>
</excludes>
</resource>
</resources>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.0</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
I tried running the servlet from command line and from withing the Server plugin on Eclipse. I get the same error:
java.lang.ClassNotFoundException: org.glassfish.jersey.servlet.ServletContainer
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1678)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1523)
at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:525)
at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:507)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:126)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1099)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1043)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4957)
at org.apache.catalina.core.StandardContext$3.call(StandardContext.java:5284)
at org.apache.catalina.core.StandardContext$3.call(StandardContext.java:5279)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:722)
The weird thing is that I can see the class among the .jar files. The class is there.
I have even tried adding the jar skipping maven, but Tomcat won't see the class.

From
Eclipse + tomcat - ClassNotFound exception on deploy
If you have installed both the Maven Eclipse Plugin and the Maven WTP Plugin this is automatic. If you don't have these installed, go ahead and install them and then once Eclipse restarts right-click on the project and do a Maven > Update project.... This will internally change the project configuration so the Maven dependencies are copied to the /WEB-INF/lib folder on your deployment target.
If you don't want to use any of these plug-ins, then you have to go to the Project properties > Deployment Assembly configuration and add your dependencies manually, but again, this is done automatically by these plug-ins.

Just a hint...
At the end, what you are creating are good old war files... which should have your libraries under WEB-INF/lib. Have you checked if it is happening? I mean, you can create your war (Export/WAR file right clicking on the project in the project explorer), and then, through your zip application, go to that WEB-INF/lib folder in the war file, and checking that your jar files are there.
If they are not there, Eclipse is not exporting your libraries into the war file correctly.
Have you added them to your build path(java build path / Libraries and java build path / Order and export)?

Add
<packaging>war</packaging>
in your pom.xml, I experienced this problem when I momentarily change the packing to jar when by using the library via
mvn clean install
which compile it to jar and can be referenced by your other projects, which is not possible to do when your packaging is war.
When you forgot to change the packing back to war I see that exact error stacktrace comes up

Maven JAR - class not found exception

I created a maven war project and added javaEE API and openCSV.
in eclipse I can see both jars, import classes and use them without any compilation errors.
but when I run the app using tomcat and trying to save a CSV file I get this exception:
java.lang.NoClassDefFoundError: au/com/bytecode/opencsv/CSVWriter
JavaEE api works fine.
I tryed to add compile but it didn't do any good.
this is my pom:
<modelVersion>4.0.0</modelVersion>
<groupId>com.training</groupId>
<artifactId>DevProject</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<dependencies>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>7.0</version>
</dependency>
<dependency>
<groupId>net.sf.opencsv</groupId>
<artifactId>opencsv</artifactId>
<version>2.3</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.6</source>
<target>1.6</target>
</configuration>
</plugin>
</plugins>
</build>
This is the code that throws the exception:
CSVWriter writer = new CSVWriter(new FileWriter("file.csv"));
Any ideas?

The default java ee api's are um...messed up.
They are not meant to actually run stuff but only to compile stuff, they don't actually have any content because of some copyright or whatever issue that I forgot about.
So when you define the dependency you should state:
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>7.0</version>
<scope>provided</scope>
</dependency>
Note that additional "scope" and add an actual implementation to your runtime.
Alternatively (what I often do to allow for testcases) you could include an actual implementation like that of jboss.

Try this:
Right click on the eclipse project containing your pom
Click on Properties
Click on Deployment Assembly
Then check that your Maven Dependencies are in the list and that the deploy path in front of them is WEB-INF/lib
Click the Add... button if necessary then Click Apply and OK buttons.