Develop Reference

maven-compiler-plugin not found

I am learning Selenium and I would like to try add the maven-compiler-plugin to pom.xml and reimport maven settings. So I found this example to do it http://maven.apache.org/plugins/maven-compiler-plugin/examples/set-compiler-source-and-target.html and tried to add the code to the pom.xml. But the vrsion from the example 3.8.1 is red like on the screenshot. What it means? It is a copy from example.
Here is the whole 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>camaj.vladimir</groupId>
<artifactId>selenium-maven</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.seleniumhq.selenium</groupId>
<artifactId>selenium-java</artifactId>
<version>3.141.59</version>
</dependency>
<dependency>
<groupId>org.seleniumhq.selenium</groupId>
<artifactId>selenium-server</artifactId>
<version>3.141.59</version>
</dependency>
<dependency>
<groupId>org.seleniumhq.selenium</groupId>
<artifactId>selenium-chrome-driver</artifactId>
<version>3.141.59</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>4.1.1</version>
</dependency>
<dependency>
<groupId>com.google.code.tempus-fugit</groupId>
<artifactId>tempus-fugit</artifactId>
<version>1.1</version>
</dependency>
<dependency>
<groupId>com.codeborne</groupId>
<artifactId>phantomjsdriver</artifactId>
<version>1.4.4</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
</project>

In my case, I have changed the tags from plugin to dependency like it is in the Maven Repository.
<dependency>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
</dependency>

In my case the groupId for the plugin was missing:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
...

In my case, Spring Boot code works fine without changing anything, however, it gives the same error when I tried to commit in Git.
To solve this, I add the version info as follows and it worked.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>${maven-compiler-plugin.version}</version>
...

I've faced this issue with my old project (which was 100% working on my old ItelliJ IDEA) and newly installed ItelliJ IDEA:
in the pom.xml I had this:
<build>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.2</version>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
</configuration>
</plugin>
</plugins>
</build>
And IDEA throwed an error maven-compiler-plugin not found. I've added
<groupId>org.apache.maven.plugins</groupId>
and IDEA found the plugin, and after that I was free to remove org.apache.maven.plugins without breaking IDEA

I got this error with IntelliJ. tried many ways, the below worked for me:
Close your IDE.
Delete "*.iml" and ".idea" -directories(present in the root folder of project)
Run "mvn clean install" from the command-line
Re-import your project into IDEA

In IntelliJ you can right click on 3.8.1 scroll down to Maven and select "Reimport". This solved the issue for me.

In my case, invalidating cache and restarting solved the issue.

Add the Following code in your pom the issue will resolve
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
<configuration>
<source>8</source>
<target>8</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>3.0.0-M1</version>
<configuration>
<useSystemClassLoader>false</useSystemClassLoader>
<forkCount>1</forkCount>
<useFile>false</useFile>
<skipTests>false</skipTests>
<testFailureIgnore>true</testFailureIgnore>
<forkMode>once</forkMode>
<suiteXmlFiles>
<suiteXmlFile>testing.xml</suiteXmlFile>
</suiteXmlFiles>
</configuration>
</plugin>
</plugins>
</build>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
Make sure you are reimporting your dependency after adding plugins

I went to
.m2\repository\org\apache\maven\plugins\maven-compiler-plugin
and removed older version. It worked

You need to update your project so that the dependencies are updated from Maven side.
To update:
Change the file structure to project view.
Right click on project name -> Maven -> Reload project
And it will download all the necessary dependencies.

One reason could be due to proxy setup on your system in Maven settings.
You can remove/backup the previous maven settings.xml file and this should work.
mv ~/.m2/settings.xml ~/.m2/settings.xml.bak

Maven Deploying Project as Jar - Missing Class definition

I am trying to create a runnable jar from a maven project created in Intellij Idea.
I tried building the Artifact through Intellij, but that did not work out. It could not find the main file.
After that I tried it through maven with:
- mvn compile
- mvn package
This creates a runnable jar which executes, but later when parsing a csv it throws an Exception:
Exception in thread "JavaFX Application Thread"
java.lang.NoClassDefFoundError: org/apache/commons/csv/CSVParser
But it is added in my pom.xml... I downloaded everything even the docs. I can see the org.apache.commons:commons-csv package in the external libraries, but it seems to be missing when creating the jar.
<?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>
<packaging>jar</packaging>
<groupId>sceosa</groupId>
<artifactId>CEO_SA_ReportingLine</artifactId>
<version>1.0-SNAPSHOT</version>
<build>
<finalName>CEOSA</finalName>
<plugins>
<!-- download source code in Eclipse, best practice -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<version>2.9</version>
<configuration>
<downloadSources>true</downloadSources>
<downloadJavadocs>false</downloadJavadocs>
</configuration>
</plugin>
<!-- Set a compiler level -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<!-- Make this jar executable -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.1.0</version>
<configuration>
<archive>
<manifest>
<mainClass>de.Main</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.hsqldb/hsqldb -->
<!-- https://mvnrepository.com/artifact/org.apache.maven.plugins/maven-compiler-plugin -->
<dependency>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.7.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.google.guava/guava -->
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>25.1-jre</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-csv</artifactId>
<version>1.3</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
Can anybody see what is wrong with the pom file or intellij?

By default maven does not include dependencies when building jars. The jar will only work if you have the dependency in some other way.
You can use the maven-assembly-plugin to build a jar-with-dependencies.

I have used the maven-shade-plugin and it works great if you want to bundle all your dependencies into one jar. All you need is the plugin and provide the Main class from your project and it should have a main method. It will look something like this:
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <executions>
        <execution>
            <goals>
                <goal>shade</goal>
            </goals>
            <configuration>
                <shadedArtifactAttached>true</shadedArtifactAttached>
                <transformers>
                    <transformer implementation=
                      "org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                        <mainClass>com.test.MainClass</mainClass>
                </transformer>
            </transformers>
        </configuration>
        </execution>
    </executions>
</plugin>
And just build your project using mvn clean install and you should find the the jar in your target directory and it will be suffixed with -shaded.jar. Hope this helps

Maven classifier empty jars

Assume we have multimodule maven project:
parent
|-module-a-jar
|-module-b-jar
|-web-module-c-war
There is common classified specified for parent pom.xml:
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.6</version>
<configuration>
<classifier>${my.project.classifier}</classifier>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.6</version>
<configuration>
<classifier>${my.project.classifier}</classifier>
</configuration>
</plugin>
</plugins>
</pluginManagement>
Assume that I build project using
mvn clean package -Dmy.project.classifier=NIGHTLY
After building web-module-c-war contains empty folders instead of jar files:
web-module-c-war
|-WEB-INF
|-lib
|-module-a-jar
|-module-a-jar
Can you please advise how to fix this? Why this is happening?
If I remove classifier from maven-jar-plugin configuration it seems to be working fine.
Thanks

why not just make this?
pom web-module-c-war :
<groupId>xxxxx</groupId>
<artifactId>xxxx</artifactId>
<version>1.0.0-SNAPSHOT</version>
<classifier>${my.project.classifier}</classifier>
..
..
<dependency>
<groupId>${project.groupId}</groupId>
<artifactId>module-a-jar</artifactId>
<version>${project.version}</version>
<classifier>${my.project.classifier}</classifier>
</dependency>
<dependency>
<groupId>${project.groupId}</groupId>
<artifactId>module-b-jar</artifactId>
<version>${project.version}</version>
<classifier>${my.project.classifier}</classifier>
</dependency>

Maven Not Copying Dependencies to WEB-INF/lib in Eclipse

I realize anywhere from very similar to identical questions have been asked numerous times on StackOverflow, but most if not all seem to end up having different solutions.
I have tried almost everything that I have found from similar questions posted here and elsewhere, yet I still can't get Maven to put the dependency JARs in WEB-INF/lib.
The oddest thing is that every time I run Maven -> Update Project, Maven seems to reconfigure the class output folder to be /target/classes instead of /war/WEB-INF/classes which is required by the Google web app plugin.
Everything shows up correctly under Maven Dependencies in the build path, but nothing shows up in WEB-INF/lib, so the app fails with ClassNotFoundExceptions at runtime.
Here is the relevant part of the pom.xml:
<packaging>war</packaging>
<build>
<sourceDirectory>src</sourceDirectory>
<resources>
<resource>
<directory>src</directory>
<excludes>
<exclude>**/*.java</exclude>
</excludes>
</resource>
</resources>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.5</version>
<configuration>
<webXml>war/WEB-INF/web.xml</webXml>
<archive>
<manifest>
<addClasspath>true</addClasspath>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>com.google.appengine.tools</groupId>
<artifactId>appengine-gcs-client</artifactId>
</dependency>
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.google.appengine.tools</groupId>
<artifactId>appengine-gcs-client</artifactId>
<version>RELEASE</version>
<scope>import</scope>
</dependency>
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.3.1</version>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
Is there something I have to configure in the M2E settings? Do I need to use a maven terminal command? I am really at a loss for what to do other than manually manage all dependencies (please... no).

<build>
<outputDirectory>war/WEB-INF/classes</outputDirectory>
</build>
Add that to your pom. It will stop the output directory changing everytime you do a Maven Update.

Cobertura doesn't work with Java 7

I am using maven 3.0.4, JRE 1.7.0_09.
When I use mvn clean install all my tests passes and everything looks good - here is my surefire plugin configuration:
<plugin>
<version>2.12.4</version>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<configuration>
<!-- -XX:-UseSplitVerifier is for java 7 -->
<argLine>-XX:-UseSplitVerifier</argLine>
</configuration>
</plugin>
Now, when I mvn cobertura:cobertura some of my tests have errors like this one:
Expecting a stackmap frame at branch target ....
And some more errors that made me understand that it is not running using JRE7 (for example, Encountered " "|" "| "" at line...)
Here is my cobertura plugin configuration:
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>cobertura-maven-plugin</artifactId>
<version>2.5.1</version>
<configuration>
<formats>
<format>html</format>
<format>xml</format>
</formats>
</configuration>
</plugin>
And the reporting is:
<reporting>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>cobertura-maven-plugin</artifactId>
<version>2.5.1</version>
<configuration>
<formats>
<format>html</format>
<format>xml</format>
</formats>
</configuration>
</plugin>
</plugins>
</reporting>
I saw a lot of threads that talk about this issue and the solution is to add this line <argLine>-XX:-UseSplitVerifier</argLine> but it does not help.
What am I doing wrong here?

We are using Cobertura plugin version 2.6 with Java 7 with no problems. This includes some files with Java 7 syntax (multi-catch, e.g.) which used to fail with the earlier plugin version. Nor do I need to use -XX:-UseSplitVerifier in the SureFire plugin any longer.
<properties>
<coberturaMavenPlugin>2.6</coberturaMavenPlugin>
<mavenSurefirePlugin>2.12</mavenSurefirePlugin>
</properties>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>${mavenSurefirePlugin}</version>
</plugin>
</plugins>
</pluginManagement>
</build>
<reporting>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>cobertura-maven-plugin</artifactId>
<version>${coberturaMavenPlugin}</version>
<configuration>
<aggregate>true</aggregate>
</configuration>
</plugin>
</plugins>
</reporting>

Further to this, the issue we had was to do with Cobertura and the version of Xalan/Xerces.
Looking at http://mojo.codehaus.org/cobertura-maven-plugin/dependencies.html, it can be seen that the cobertura plugin has Transitive Dependencies on Xalan 2.6.0 & Xerces at 2.6.2.
To combat this, I added:
<dependency>
<groupId>xalan</groupId>
<artifactId>xalan</artifactId>
<version>2.7.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>xerces</groupId>
<artifactId>xercesImpl</artifactId>
<version>2.11.0</version>
<scope>test</scope>
</dependency>
And the tests passed, both during the initial test phase with surefire and the cobertura phase.

Perhaps you can set the compiler source and target version options to version "1.6" Different versions of build tools may choose different defaults for this setting. (Buildr 1.4 defaults to source and target 1.7 these days; Maven 2.x still uses 1.6 or earlier.)