Develop Reference

IntelliJ - Module xx is imported From Maven. Any changes made in its configuration might be lost after reimporting mean?

IntelliJ displays these warning messages at Modules
enter image description here " Module xx is imported From Maven. Any changes made in its configuration might be lost after reimporting." (Note, this happens only when I press the Apply button on the Module)
I want to know what this means in detail and the solution...
For information Here:
<?xml version="1.0" encoding="UTF-8"?>
4.0.0
<groupId>me.codingtime</groupId>
<artifactId>NetworkPlugin</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<name>NetworkPlugin</name>
<properties>
<java.version>1.8</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>3.2.4</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<createDependencyReducedPom>false</createDependencyReducedPom>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
<repositories>
<repository>
<id>spigotmc-repo</id>
<url>https://hub.spigotmc.org/nexus/content/repositories/snapshots/</url>
</repository>
<repository>
<id>sonatype</id>
<url>https://oss.sonatype.org/content/groups/public/</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>org.spigotmc</groupId>
<artifactId>spigot-api</artifactId>
<version>1.17.1-R0.1-SNAPSHOT</version>
<scope>provided</scope>
</dependency>
</dependencies>

This error means that you must not modify the project structure and build configuration like project dependencies, compiler settings, sources/resources directories etc using IDE UI dialogs. Instead, you must do corresponding changes in the Maven pom.xml file.
Because otherwise you will loose all such changes made in IDE UI after the project fill be Reloaded by the IDE from the maven build files (pom.xml).

Incompatible class versions when submitting Flink a job

I'm trying to submit a streaming job using Beam 2.27/Flink 1.12, using the following Maven command-line:
mvn exec:java -Dexec.mainClass=org.example.MyPipelineClass -Pflink-runner -Dexec.args="--runner=FlinkRunner --flinkMaster=flink-host:8081 --filesToStage=target/pipelines-bundled-1.0.0.jar"
Things were working smoothly for a bit, but I recently made some edits and wanted to run a new version of the pipeline and am now getting the following error:
Caused by: java.io.InvalidClassException: org.apache.flink.streaming.api.graph.StreamConfig$NetworkInputConfig; local class incompatible: stream classdesc serialVersionUID = -3137689219135046939, local class serialVersionUID = 3698633776553163849
at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:699)
at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:2003)
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1850)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2160)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1667)
at java.io.ObjectInputStream.readArray(ObjectInputStream.java:2093)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1655)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:503)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:461)
at org.apache.flink.util.InstantiationUtil.deserializeObject(InstantiationUtil.java:615)
at org.apache.flink.util.InstantiationUtil.deserializeObject(InstantiationUtil.java:600)
at org.apache.flink.util.InstantiationUtil.deserializeObject(InstantiationUtil.java:587)
at org.apache.flink.util.InstantiationUtil.readObjectFromConfig(InstantiationUtil.java:541)
at org.apache.flink.streaming.api.graph.StreamConfig.getInputs(StreamConfig.java:263)
... 21 more
My pom.xml looks something like this:
<?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>pipelines</artifactId>
<version>1.0.0</version>
<packaging>jar</packaging>
<properties>
<beam.version>2.27.0</beam.version>
<flink.version>1.12</flink.version>
<maven-compiler-plugin.version>3.7.0</maven-compiler-plugin.version>
<maven-exec-plugin.version>1.6.0</maven-exec-plugin.version>
<maven-jar-plugin.version>3.2.0</maven-jar-plugin.version>
<maven-shade-plugin.version>3.1.0</maven-shade-plugin.version>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>${maven-compiler-plugin.version}</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>${maven-jar-plugin.version}</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>${maven-shade-plugin.version}</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<finalName>${project.artifactId}-bundled-${project.version}</finalName>
<filters>
<filter>
<artifact>*:*</artifact>
<excludes>
<exclude>META-INF/LICENSE</exclude>
<exclude>META-INF/*.SF</exclude>
<exclude>META-INF/*.DSA</exclude>
<exclude>META-INF/*.RSA</exclude>
</excludes>
</filter>
</filters>
<transformers>
<transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
</transformers>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>${maven-exec-plugin.version}</version>
<configuration>
<cleanupDaemonThreads>false</cleanupDaemonThreads>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
<profiles>
<profile>
<id>flink-runner</id>
<dependencies>
<dependency>
<groupId>org.apache.beam</groupId>
<artifactId>beam-runners-flink-${flink.version}</artifactId>
<version>${beam.version}</version>
<scope>runtime</scope>
</dependency>
</dependencies>
</profile>
</profiles>
<dependencies>
<dependency>
<groupId>org.apache.beam</groupId>
<artifactId>beam-sdks-java-core</artifactId>
<version>${beam.version}</version>
</dependency>
<!-- note that the pipeline runs on GCP -->
<dependency>
<groupId>org.apache.beam</groupId>
<artifactId>beam-sdks-java-io-google-cloud-platform</artifactId>
<version>${beam.version}</version>
<exclusions>
<exclusion>
<groupId>com.google.cloud.bigtable</groupId>
<artifactId>bigtable-client-core</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- main output is JDBC/Postgres -->
<dependency>
<groupId>org.apache.beam</groupId>
<artifactId>beam-sdks-java-io-jdbc</artifactId>
<version>${beam.version}</version>
</dependency>
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>42.2.4</version>
</dependency>
</dependencies>
</project>
Of course, before submitting the job I built the JAR using mvn clean package -Pflink-runner.
Flink is self-hosted on a GKE instance, and is deployed using the flink:1.12.4-java8 image.
I found this issue which seems to have the same error message, but no clear offender.
Any help or ideas to explore would be greatly appreciated, I have no idea what to investigate.

I found the issue own my own. In the pom.xml above, I specified that the Beam runner was beam-runners-flink-1.12, and the cluster was running Flink 1.12.4
Beam's Flink runner does not specify a patch, and uses Flink 1.12.0
Downgrading the cluster fixed my issue.

How to create a runnable jar file with AspectJ?

I'm using Eclipse to compile java code with aspectj.
My code (with the aspect) works fine, but I'm struglling to create a jar file of this my code.
For example, if I select Export > Runnable JAR file, in the combo box I don't see my project (all the other project that not based on aspecj are showing up in the combo box).

If you like to have repeatable builds which work from command line as well as from IDEs like Eclipse or IntelliJ IDEA, I recommend a Maven build. The onejar-maven-plugin creates a runnable JAR including AspectJ runtime and all other declared dependencies for you:
<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>de.scrum_master.stackoverflow</groupId>
<artifactId>my_project</artifactId>
<version>1.0.0-SNAPSHOT</version>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.source-target.version>1.7</java.source-target.version>
<aspectj.version>1.8.8</aspectj.version>
<main-class>de.scrum_master.app.Application</main-class>
</properties>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.3</version>
<configuration>
<source>${java.source-target.version}</source>
<target>${java.source-target.version}</target>
<!-- IMPORTANT -->
<useIncrementalCompilation>false</useIncrementalCompilation>
</configuration>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>aspectj-maven-plugin</artifactId>
<version>1.8</version>
<configuration>
<!--<showWeaveInfo>true</showWeaveInfo>-->
<source>${java.source-target.version}</source>
<target>${java.source-target.version}</target>
<Xlint>ignore</Xlint>
<complianceLevel>${java.source-target.version}</complianceLevel>
<encoding>${project.build.sourceEncoding}</encoding>
<!--<verbose>true</verbose>-->
<!--<warn>constructorName,packageDefaultMethod,deprecation,maskedCatchBlocks,unusedLocals,unusedArguments,unusedImport</warn>-->
</configuration>
<executions>
<execution>
<!-- IMPORTANT -->
<phase>process-sources</phase>
<goals>
<goal>compile</goal>
<goal>test-compile</goal>
</goals>
</execution>
</executions>
<dependencies>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjtools</artifactId>
<version>${aspectj.version}</version>
</dependency>
</dependencies>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>1.4.0</version>
<configuration>
<mainClass>${main-class}</mainClass>
</configuration>
</plugin>
<plugin>
<groupId>org.dstovall</groupId>
<artifactId>onejar-maven-plugin</artifactId>
<version>1.4.4</version>
<executions>
<execution>
<goals>
<goal>one-jar</goal>
</goals>
</execution>
</executions>
<configuration>
<onejarVersion>0.96</onejarVersion>
<mainClass>${main-class}</mainClass>
<attachToBuild>true</attachToBuild>
</configuration>
</plugin>
</plugins>
</pluginManagement>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>aspectj-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.dstovall</groupId>
<artifactId>onejar-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
<pluginRepositories>
<pluginRepository>
<id>OneJAR googlecode.com</id>
<url>http://onejar-maven-plugin.googlecode.com/svn/mavenrepo</url>
</pluginRepository>
</pluginRepositories>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>${aspectj.version}</version>
<scope>runtime</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjrt</artifactId>
</dependency>
</dependencies>
<organization>
<name>Scrum-Master.de - Agile Project Management</name>
<url>http://scrum-master.de</url>
</organization>
</project>

Try to create a normal run configuration with the same start class as your AspectJ run configuration. When you create your runnable JAR, select the normal run configuration. The resulting JAR will have AspectJ support.
You can find here the answer :
https://www.eclipse.org/forums/index.php/t/204968/

The runnable jar exporter only works with Java Application type launch configs, but that shouldn't be a problem. Create a normal Java Application launch config with your main class and export the runnable jar based on that newly created launch config. It should work.

Maven running tests annotated with junit #Ignore when building Java project

I've annotated a bad test with #Ignore, both on the method-level and on the class level. When running the test through the command line (I've tried "mvn clean install", "mvn test", "mvn clean install -DskipTests; mvn test"), however, the #Ignore annotation is ignored, the test is run, and- as it is a bad test- it fails.
Here is the test:
public class UserTest extends PersistentTestBase {
#Test
#Ignore
public void testPersistence() {
...
}
}
And here is my 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>
...
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
...
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
...
<!-- Testing -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.jmock</groupId>
<artifactId>jmock-junit4</artifactId>
<version>2.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.jmock</groupId>
<artifactId>jmock-legacy</artifactId>
<version>2.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.easymock</groupId>
<artifactId>easymock</artifactId>
<version>3.4</version>
<scope>test</scope>
</dependency>
...
<!-- For dep management, see Mykong.com's "How to create a jar file with Maven" -->
<build>
<plugins>
<!-- Necessary to force language level of Java 8 -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.2</version>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.18.1</version>
<configuration>
<junitArtifactName>junit:junit-dep</junitArtifactName>
<useFile>false</useFile>
<trimStackTrace>false</trimStackTrace>
<reuseForks>false</reuseForks>
<forkCount>1</forkCount>
</configuration>
</plugin>
<!-- Packages into a jar, looking for deps in target/dependency-jars -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.2</version>
<configuration>
<excludes>
<exclude>**/log4j.properties</exclude>
</excludes>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>...Application</mainClass>
<classpathPrefix>dependency-jars</classpathPrefix>
</manifest>
</archive>
</configuration>
</plugin>
<!-- Moves all compiled deps to target/dependency-jars -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.5.1</version>
<executions>
<execution>
<id>copy-dependencies</id>
<phase>package</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<includeScope>runtime</includeScope>
<outputDirectory>${project.build.directory}/dependency-jars</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<configuration>
<mainClass>...Application</mainClass>
</configuration>
</plugin>
</plugins>
</build>
Worth noting that the test is skipping when the class is run in Intellij IDEA 14, and that there are some other issues with tests failing on mvn test that are passing in Intellij (but are out of the scope of this question). Thank you for the help!

For those who are working with Junit 5.
#Ignore did not work formaven surefire neither Intellij tests even if I had already included junit-vintage-engine
I used #Disabled and it worked for maven at least!

Wemu posted the solution:
I think you can simply remove:
junit:junit-dep from the
surefire config – wemu Nov 20 at 7:10
Removed the element and all tests passed!

I had a same problem with the JUNIT library. After so many tries, it worked with the Pom.xml below:
<repositories>
<repository>
<id>junit</id>
<url>http://junit.org</url>
</repository>
</repositories>
<dependencies>
<dependency><groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version></dependency>
</dependencies>

For me the solution was to simply update the JUnit version to 4.13:
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13</version>
<scope>test</scope>
</dependency>

Add groovy library in mvn project

I'm new into Groovy and I'm trying to write a very simple project using Groovy as language. I was able to write a hello world script, deploy an mvn artifact and execute it.
I'm going beyond that right now and I need to import some external libraries for testing matters but I don't know how to do that.
I would really appreciate if you could give me some tips about this.
Thanks!

You can specify dependencies for the project which have test scope, in which case they will not be used in compile scope, or you can specify dependencies which are only used in certain scenarios (if, for example, you want to write Groovy tests without requiring the rest of your team to do so).
This sample pom.xml has a custom profile element which describes dependencies and executions to run only if the current environment user is "andylopresto". This means that if my team doesn't want to use Groovy in their build, I could still write my test classes in Groovy and have them run as part of the standard mvn test phase on my machine only. In my team members' local machines (or a shared Jenkins instance), the Groovy test files will be ignored (not compiled or run, and the groovy-all dependency will not even be downloaded onto the machine).
Example:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://maven.apache.org/POM/4.0.0"
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>your.package</groupId>
<artifactId>artifact</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>pom</packaging>
<developers>
<developer>
<id>alopresto</id>
<name>Andy LoPresto</name>
<email>alopresto#example.com</email>
<roles>
<role>developer</role>
<role>owner</role>
</roles>
</developer>
<developer>
<id>jjava</id>
<name>Johnny Java</name>
<email>ihategroovy#example.com</email>
<roles>
<role>sticking to older languages</role>
</roles>
</developer>
</developers>
<dependencyManagement>
<dependencies>
<!-- This dependency is available to all project code -->
<dependency>
<groupId>commons-codec</groupId>
<artifactId>commons-codec</artifactId>
<version>1.9</version>
</dependency>
<!-- This dependency is only available during test phase -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
<!-- This dependency is expected to be provided outside of Maven -->
<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-util</artifactId>
<version>8.0.8</version>
<scope>provided</scope>
</dependency>
</dependencies>
</dependencyManagement>
<profiles>
<profile>
<!-- Custom profile for Groovy tests used only on Andy's computer -->
<id>andyLocalTest</id>
<activation>
<property>
<name>env.USER</name>
<value>andylopresto</value>
</property>
</activation>
<dependencies>
<dependency>
<groupId>org.codehaus.groovy</groupId>
<artifactId>groovy-all</artifactId>
<version>2.2.1</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>build-helper-maven-plugin</artifactId>
<version>1.8</version>
<executions>
<execution>
<id>add-source</id>
<phase>generate-sources</phase>
<goals>
<goal>add-source</goal>
</goals>
<configuration>
<sources>
<source>src/main/groovy</source>
</sources>
</configuration>
</execution>
<execution>
<id>add-test-source</id>
<phase>generate-test-sources</phase>
<goals>
<goal>add-test-source</goal>
</goals>
<configuration>
<sources>
<source>src/test/groovy</source>
</sources>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<compilerId>groovy-eclipse-compiler</compilerId>
<source>1.6</source>
<target>1.6</target>
<includes>
<include>**/*.java</include>
<include>**/*.groovy</include>
</includes>
</configuration>
<dependencies>
<dependency>
<groupId>org.codehaus.groovy</groupId>
<artifactId>groovy-eclipse-compiler</artifactId>
<version>2.8.0-01</version>
</dependency>
<dependency>
<groupId>org.codehaus.groovy</groupId>
<artifactId>groovy-eclipse-batch</artifactId>
<version>2.1.5-03</version>
</dependency>
</dependencies>
</plugin>
</plugins>
</build>
</profile>
</profiles>