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How to pass --illegal-access JVM argument to spring boot maven plugin

I have an application that runs just fine when running this from the command prompt :
java -jar --illegal-access=permit target/Something.jar
However, configuring my spring boot maven plugin in my pom.xml as such gives me the same error as if I ran my cmd without the illegal-access=permit part, telling me it is being ignored :
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
<configuration>
<mainClass>com.something.PreMain</mainClass>
<jvmArguments>
--illegal-access=permit
</jvmArguments>
</configuration>
</plugin>
What am I doing wrong? This app worked perfectly in java 14 and I'm in the process of upgrading to java 16. Everything still works perfectly except intelliJ not being able to launch it in debug mode due to the missing illegal-access=permit JVM argument.

If you're trying to run the application in IntelliJ, you don't need to pass anything into Maven. In IntelliJ, open the run configuration for your app and under Environment->VM options add --illegal-access=permit. See the attached image, Main class would be your fully qualified location of your #SpringBootApplication class, e.g. com.something.MySpringBootApplication
When you start your app in debug mode in IntelliJ, you'll see something like
/Library/Java/JavaVirtualMachines/jdk-16.0.2.jdk/Contents/Home/bin/java -agentlib:jdwp=transport=dt_socket,address=127.0.0.1:52737,suspend=y,server=n --illegal-access=permit -XX:TieredStopAtLevel=1..., notice the argument getting passed to your app.

You may want to try putting it in the properties instead. Try this:
<properties>
<jvm.options>--illegal-access=permit</jvm.options>
</properties>
Then use it in the plugin as follows:
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
<configuration>
<mainClass>com.something.PreMain</mainClass>
<compilerArgs>
<arg>${jvm.options}</arg>
</compilerArgs>
</configuration>
Note: Instead of args, you would need to use argline if you're accessing illegal-access parameter for surefire.

exec-maven-plugin: Can I run exec:exec goal without first running the toolchains:toolchain goal?

I've inherited an application that only compiles and runs in Java 1.8. Because I don't want to make Java 1.8 the primary jvm on my machine, I felt that the best way to manage this was through Maven toolchains. Configuring the maven-compiler-plugin was pretty straight forward, but I also want to add the ability to execute the service via Maven in order to take advantage of the toolchain I have configured for 1.8.
The challenge is that I don't seem to be able to get the exec-maven-plugin to use the toolchain as documented. According to the documentation, I would think that the exec-maven-plugin would utilize the maven-toolchains-plugin as needed. However, in order to get exec:exec to use the right toolchain, I have to use:
mvn toolchains:toolchain exec:exec
This works, but the documentation leads me to think that the toolchain would be configured automatically without me needing to execute the toolchains:toolchain goal.
pom.xml
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-toolchains-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>toolchain</goal>
</goals>
</execution>
</executions>
<configuration>
<toolchains>
<jdk>
<version>1.8</version>
</jdk>
</toolchains>
</configuration>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<configuration>
<executable>java</executable>
<arguments>
<argument>-classpath</argument>
<classpath></classpath>
<argument>com.my.Main</argument>
</arguments>
</configuration>
</plugin>
</plugins>
</build>
toolchains.xml
<?xml version="1.0" encoding="UTF8"?>
<toolchains>
<toolchain>
<type>jdk</type>
<provides>
<id>1.8</id>
<version>1.8</version>
</provides>
<configuration>
<jdkHome>/Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home</jdkHome>
</configuration>
</toolchain>
</toolchains>
Additional Note: I also tried configuring the exec-maven-plugin to run on exec:java with the following configuration:
<configuration>
<mainClass>com.my.Main</mainClass>
</configuration>
However this does not work, not even with mvn toolchains:toolchain exec:java.
Is there a way to configure this so that I only have to run mvn exec:exec, or mvn exec:java?

I think the answer is you must ensure that the toolchains plugin itself is part of your build. Or that's what the relevant documentation seems to say. (I see above you have that; what I'm saying is yes, that is required.)

Automatically generate Java from .proto with maven/m2e in Eclipse IDE

For my team, I'd like to configure maven/eclipse build to automatically generate Java code from *.proto files (in a project that uses gRPC). Currently one needs to run mvn generate-source or mvn protobuf:compile (as in plugin usage page). Or what is the same add Run configuration to invoke maven goal compile.
Whenever Eclipse Maven project is refreshed (Alt+F5) or IDE is restarted, project is rebuilt but without what should appear in target/generated, thus turning project into red. So one need to generate and refresh project (F5). UPDATE Eclipse has needed source folders configured in .clathpath file.
As I know that should be m2e connector, but I could only find one https://github.com/masterzen/m2e-protoc-connector for the oldest Googles plugin com.google.protobuf.tools:maven-protoc-plugin, that is even not mentioned currently at https://github.com/grpc/grpc-java
We use exactly referenced/recommended
<groupId>org.xolstice.maven.plugins</groupId>
<artifactId>protobuf-maven-plugin</artifactId>
that is:
<build>
<extensions>
<extension>
<groupId>kr.motd.maven</groupId>
<artifactId>os-maven-plugin</artifactId>
<version>1.4.1.Final</version>
</extension>
</extensions>
<plugins>
<plugin>
<groupId>org.xolstice.maven.plugins</groupId>
<artifactId>protobuf-maven-plugin</artifactId>
<version>0.5.0</version>
<configuration>
<protocArtifact>com.google.protobuf:protoc:3.1.0:exe:${os.detected.classifier}</protocArtifact>
<pluginId>grpc-java</pluginId>
<pluginArtifact>io.grpc:protoc-gen-grpc-java:1.0.1:exe:${os.detected.classifier}</pluginArtifact>
</configuration>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>compile-custom</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
Related:
Linking to generated Java protobuf code in Eclipse
looked at this but that author was using other older, not supported now plugin : Eclipse build loop caused by protobuf generated code (related to Maven Project Builder)
P.P.S That plugin https://github.com/igor-petruk/protobuf-maven-plugin however has continuation as https://github.com/os72/protoc-jar-maven-plugin

Instead of using org.xolstice.maven.plugins:protobuf-maven-plugin my team has used com.github.os72:protoc-jar-maven-plugin to generate the message classes. I believe they are the same since under the hood they all seem to be using the tools from Google.
I am not using any m2e connectors for this plugin (Edit: protoc-jar-maven-plugin's m2e connector is bundled with it so no extra installation is needed, which is why it seemed like I wasn't using one, but technically I was, but this doesn't really matter). Unfortunately the changes in the .proto file are not "automatically" propagated to the generated .java files, you need to manually run Maven or trigger the project to be built in Eclipse (instructions below), but fortunately the target/generated-sources file is not vanishing or emptying or anything strange like what you describe.
If you want to rebuild the .java files from the .proto classes without using mvn clean compile from the command line you can clean the Eclipse project . Project → Clean... → select your project → Select build option (only shows if you have "Build Automatically" from the Project menu is unchecked).
I was able to do this in the latest Eclipse Neon (it will probably work in later ones too, but I don't know for certain).
Below is the POM I am using. I don't think it requires any special explanation, my solution is to simply use a different plugin than the one you are using. (If some explanation is needed I'll be happy to provide it though.)
<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>io.github.jacksonbailey</groupId>
<artifactId>protobuf-m2e-sample</artifactId>
<version>0.1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>com.google.protobuf</groupId>
<artifactId>protobuf-java</artifactId>
<version>3.1.0</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>com.github.os72</groupId>
<artifactId>protoc-jar-maven-plugin</artifactId>
<version>3.1.0.1</version>
<executions>
<execution>
<phase>generate-sources</phase>
<goals>
<goal>run</goal>
</goals>
<configuration>
<protocVersion>3.1.0</protocVersion>
<inputDirectories>
<include>src/main/resources</include>
</inputDirectories>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>

for protobuf-maven-plugin
Thanks to sergei-ivanov answer in https://github.com/xolstice/protobuf-maven-plugin/issues/16, that gave link https://github.com/trustin/os-maven-plugin#issues-with-eclipse-m2e-or-other-ides :
One need to download os-maven-plugin-x.x.x.Final.jar (the version as in your pomx.ml) and put it into the <ECLIPSE_HOME>/plugins directory.
After that Eclipse will generate source on project clean, including after Maven -update project... (Alt+F5), but not after Project -> Build (or with default Build Automatically). Also on IDE start it will not compile.
Yes, that is illogical:
Project - Clean will generate and compile Java source
but
Project - Build will not.
P.S. Raised Bug 507412

Both eclipse and vscode can automatically compile proto when changed.
<plugin>
<groupId>kr.motd.maven</groupId>
<artifactId>os-maven-plugin</artifactId>
<version>1.6.2</version>
<executions>
<execution>
<phase>initialize</phase>
<goals>
<goal>detect</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.xolstice.maven.plugins</groupId>
<artifactId>protobuf-maven-plugin</artifactId>
<version>0.6.1</version>
<configuration>
<protocArtifact>com.google.protobuf:protoc:3.12.0:exe:${os.detected.classifier}</protocArtifact>
<pluginId>grpc-java</pluginId>
<pluginArtifact>io.grpc:protoc-gen-grpc-java:1.32.1:exe:${os.detected.classifier}</pluginArtifact>
</configuration>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>compile-custom</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
<configuration>
<source>8</source>
<target>8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
See: https://github.com/trustin/os-maven-plugin#issues-with-eclipse-m2e-or-other-ides

How to specify javax.xml.accessExternalSchema for the JAXB2 Maven plugin

I have a maven plugin (jaxb2) and I need to supply a jvm arg to it. I don't think there is a tag to add jvm args in the pom for it.
I know I can pass in jvm args on the command line eg: mvn clean install -Djavax.xml.accessExternalSchema=all
Is it possible to set this jvm arg in the pom so that I don't have to type it into the command line every time?
(As aside - this jvm arg is required in order for it to work with JAVA-8. It works fine with JAVA-7)

This is relevant to the new XML security properties in JAXB 1.5, introduced in Java 8. This is why your builds now fail on Java 8 but work with Java 7.
If you're using my maven-jaxb2-plugin, please upgrade to the version 0.9.0 or later (current is 0.10.0). It has now a accessExternalSchema switch (default is all).
This sets precisely javax.xml.accessExternalSchema=all.
Please see the documentation.

I came across this issue while working with jaxb2-maven-plugin. I found a related jira issue for maven-jabx2-plugin - https://java.net/projects/maven-jaxb2-plugin/lists/issues/archive/2014-03/message/0
According to this issue Stephan202 suggested using properties-maven-plugin which worked like charm. Here is a sample code from his post -
<plugin>
<!-- We use this plugin to ensure that our usage of the
maven-jaxb2-plugin is JDK 8 compatible in absence of a fix
for https://java.net/jira/browse/MAVEN_JAXB2_PLUGIN-80. -->
<groupId>org.codehaus.mojo</groupId>
<artifactId>properties-maven-plugin</artifactId>
<version>1.0-alpha-2</version>
<executions>
<execution>
<id>set-additional-system-properties</id>
<goals>
<goal>set-system-properties</goal>
</goals>
</execution>
</executions>
<configuration>
<properties>
<property>
<name>javax.xml.accessExternalSchema</name>
<value>file,http</value>
</property>
</properties>
</configuration>
</plugin>

Re; the post - "I needed a solution that doesn't use alpha versions as that is my companies rules. –"
Changing the version to 1.0 & the value to 'all' got it working for me:
<plugin>
<!-- We use this plugin to ensure that our usage of the
maven-jaxb2-plugin is JDK 8 compatible in absence of a fix
for https://java.net/jira/browse/MAVEN_JAXB2_PLUGIN-80. -->
<groupId>org.codehaus.mojo</groupId>
<artifactId>properties-maven-plugin</artifactId>
<!--
<version>1.0-alpha-2</version> -->
<version>1.0.0</version>
<executions>
<execution>
<id>set-additional-system-properties</id>
<goals>
<goal>set-system-properties</goal>
</goals>
</execution>
</executions>
<configuration>
<properties>
<property>
<name>javax.xml.accessExternalSchema</name>
<value>all</value>
</property>
</properties>
</configuration>
</plugin>

It has worked for me :
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>jaxws-maven-plugin</artifactId>
<executions>
<execution>
<phase>process-sources</phase>
<goals>
<goal>wsimport</goal>
</goals>
<configuration>
<vmArgs>
<arg>-Djavax.xml.accessExternalSchema=all</arg>
</vmArgs>
<keep>true</keep>
<verbose>true</verbose>
<wsdlDirectory>${project.build.directory}/wsdl</wsdlDirectory>
<wsdlFiles>
<wsdlFile>ServiceWsService.wsdl</wsdlFile>
</wsdlFiles>
<bindingFiles>
<bindingFile>custom-binding.xml</bindingFile>
<bindingFile>custom-binding2.xml</bindingFile>
</bindingFiles>
</configuration>
</execution>
</executions>
</plugin>

Take a look at the Maven Compiler Plugin. Specifically you should be able to use the <compilerArgument> element to pass settings to the compiler.
See http://maven.apache.org/plugins/maven-compiler-plugin/examples/pass-compiler-arguments.html for examples.

If you are trying to change the behavior of the JVM that is running Maven itself, add options to MAVEN_OPTS in the environment before launching mvn.

For maven-jaxb2-plugin version 2.5.0 trying to generate from DTD and spitting
org.xml.sax.SAXParseException: External parsing is disabled. Cannot
parse URI: ...
it helped adding the following to plugin configuration
<configuration>
...
<externalEntityProcessing>true</externalEntityProcessing>
</configuration>

Is it possible to compile grunt project from maven?

I'm trying to execute grunt tasks from within maven without needing to install Node.js or anything. This is because I wan't my artifact to be packaged by Jenkins and I can't install Node.js on that machine.
I know that it's easy with npm and a few commands to get it working, but I also think that it should be easy to integrate with maven, the problem is that I don't know where to start since I'm new to npm.

Yes, using the frontend-maven-plugin, you can compile Grunt projects via Maven (found via the NodeJS mailing list).
As the documentation points out, the plugin has the following features:
Let you keep your frontend and backend builds as separate as possible, by reducing the amount of interaction between them to the bare minimum; using only 1 plugin.
Let you use Node.js and its libraries in your build process without installing Node/NPM globally for your build system
Let you ensure that the version of Node and NPM being run is the same in every build environment
I've walked through the code and it's fairly simple. Thank goodness someone finally put this together; it's an elegant solution. The repository includes an example that uses a regular Gruntfile.js to invoke jshint analysis.

UPDATE 2014-09-19: This is no longer the most accurate answer - please take a look at some of the other answers below. It was accurate at the time when I answered the question, but there seems to have been a good deal of progress in this area since then.
I'm afraid you're out of luck. Grunt is built using node and needs to be installed using npm. You might be able to copy an existing installation of Grunt from another machine if you don't want to use npm, but will still use the grunt executable and all of its dependencies on your build server.
In addition to that, many of the Grunt tasks are implemented as Node.js modules, and you will have to install them as well. Again, you might be able to copy them from another server, where you've done the Node.js/Grunt installation, but at one point, you have to do it.
For running Grunt from Maven, your best bet is to use the Maven exec plugin and then execute the grunt executable from there.
As an alternative, there are several Maven plugins that allow you to do things similar to Grunt in a Java-based fashion. They require additional configuration not compatible with Grunt, so YMMV. One that I've used in the past is http://code.google.com/p/wro4j/, which comes with a Maven plugin as well: http://code.google.com/p/wro4j/wiki/MavenPlugin
Any particular reason why you can't install Node.js on your build server?

You can use grunt-maven-plugin. It allows you to easily integrate Grunt tasks into Maven build process. No dirty hacks.
This is what I use in my current project and it works just perfect.

Finally I ended up with this (which is close enough but doesn't solve the problem):
<plugin>
<groupId>org.mule.tools.javascript</groupId>
<artifactId>npm-maven-plugin</artifactId>
<version>1.0</version>
<executions>
<execution>
<phase>generate-resources</phase>
<goals>
<goal>fetch-modules</goal>
</goals>
<configuration>
<packages>
<package>grunt-cli:0.1.6</package>
</packages>
</configuration>
</execution>
</executions>
</plugin>
that installs locally the grunt-cli, but if I don't have installed node.js it's worthless. Although I try to install node.js locally there's the need to have installed python, g++ and make. So I'll go with the KISS solution: install grunt in the build server.
References:
https://github.com/mulesoft/npm-maven-plugin
https://github.com/joyent/node/wiki/Installing-Node.js-via-package-manager
https://github.com/mcheely/requirejs-maven-plugin

You might want to checkout http://jhipster.github.io/ : it's a Yeoman generator, that generates an application which has Maven, Grunt and Bower all working together.
It's a bit like your third option, but everything is configured for you, which isn't that easy. It's also generating the basic AngularJS and Java REST services for you

This is a full copy/paste solution which work in 2017 using frontend-maven-plugin for front build, and maven-war-plugin to build the war.
What it does ? install npm, bower grunt,and everything you need, then run npm install, bower install and finally grunt build.
You can remove/add replace the steps you want, for me it's a full 30 sec install/build library and project.
<dependencies>
...
</dependencies>
<dependencyManagement>
<dependencies>
<!-- https://mvnrepository.com/artifact/com.github.eirslett/frontend-maven-plugin -->
<dependency>
<groupId>com.github.eirslett</groupId>
<artifactId>frontend-maven-plugin</artifactId>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.4</version>
<configuration>
<warSourceDirectory>src/main/webapp/YourFrontJsFolder/dist</warSourceDirectory>
<warName>YouWarName</warName>
<failOnMissingWebXml>false</failOnMissingWebXml>
<warSourceExcludes>node_modules/**</warSourceExcludes>
<includeScope>system</includeScope>
<webResources>
<resource>
<directory>WebContent/WEB-INF</directory>
<targetPath>WEB-INF</targetPath>
<includes>
<include>**/*.jar</include>
<include>**/*.jsp</include>
</includes>
</resource>
</webResources>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.3</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
<encoding>Cp1252</encoding>
</configuration>
</plugin>
</plugins>
</pluginManagement>
<finalName>YourAppName</finalName>
</build>
<profiles>
<profile>
<id>release</id>
<build>
<plugins>
<plugin>
<groupId>com.github.eirslett</groupId>
<artifactId>frontend-maven-plugin</artifactId>
<executions>
<execution>
<!-- optional: you don't really need execution ids, but it looks
nice in your build log. -->
<id>install node and npm</id>
<goals>
<goal>install-node-and-npm</goal>
</goals>
<!-- optional: default phase is "generate-resources" -->
<phase>generate-resources</phase>
<configuration>
<nodeVersion>v7.6.0</nodeVersion>
</configuration>
</execution>
<execution>
<id>npm install</id>
<goals>
<goal>npm</goal>
</goals>
<!-- optional: default phase is "generate-resources" -->
<phase>generate-resources</phase>
<configuration>
<arguments>install</arguments>
</configuration>
</execution>
<execution>
<id>bower install</id>
<goals>
<goal>bower</goal>
</goals>
<configuration>
<!-- optional: The default argument is actually "install", so unless
you need to run some other bower command, you can remove this whole <configuration>
section. -->
<arguments>install</arguments>
</configuration>
</execution>
<execution>
<id>grunt build</id>
<goals>
<goal>grunt</goal>
</goals>
<!-- optional: the default phase is "generate-resources" -->
<phase>generate-resources</phase>
<configuration>
<!-- optional: if not specified, it will run Grunt's default task
(and you can remove this whole <configuration> section.) -->
<arguments>build</arguments>
</configuration>
</execution>
</executions>
<configuration>
<installDirectory>target</installDirectory>
<workingDirectory>src/main/webapp/YourFrontJsFolder</workingDirectory>
</configuration>
</plugin>
</plugins>
</build>
</profile>
<profile>
<id>debug</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
</profile>
<profile>
<id>IDE</id>
<activation>
<property>
<name>m2e.version</name>
</property>
</activation>
<build>
<!-- Put the IDE's build output in a folder other than target, so that
IDE builds don't interact with Maven builds -->
<directory>target-ide</directory>
</build>
</profile>
</profiles>
Then you can Run as -> Maven build ..., with goal clean install and profile release

The first problem is that Maven is Java, but Grunt.js runs on the Node.js runtime. The easiest integration I ever achieved between the two involved the maven-exec-plugin. The maven-exec-plugin is capable of executing .sh/.bat/.cmd scripts, whichever are native to the OS you are using. So during a Maven build I would have the maven-exec-plugin execute a script named optimize-js.sh, for example, which would simply do something like “grunt release –force”, or whatever. The scripts can be made to do whatever. The important thing is to configure the maven-exec-plugin to execute them in the correct working directory. Of course, “grunt” and “node” need to be executable from the command-line.

If the problem is installing NodeJS on the Jenkins machine then you can use the NodeJS Jenkins plugin.
https://wiki.jenkins-ci.org/display/JENKINS/NodeJS+Plugin
We're not using it with Maven (yet) but we've got grunt running.

Can be done with exec-maven-plugin.
Define a script and dependency to grunt-cli in your package.json:
...
"scripts": {
"build": "./node_modules/.bin/grunt install"
},
"devDependencies": {
"grunt-cli": "^1.2.0",
...
In your pom, add the commands to run:
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>X.Y.Z</version>
<executions>
<execution>
<id>exec-npm-install</id>
<phase>generate-sources</phase>
<configuration>
<workingDirectory>${project.basedir}</workingDirectory>
<executable>npm</executable>
<arguments>
<argument>install</argument>
</arguments>
</configuration>
<goals>
<goal>exec</goal>
</goals>
</execution>
<execution>
<id>exec-grunt-install</id>
<phase>generate-sources</phase>
<configuration>
<workingDirectory>${project.basedir}</workingDirectory>
<executable>npm</executable>
<arguments>
<argument>run</argument>
<argument>build</argument>
</arguments>
</configuration>
<goals>
<goal>exec</goal>
</goals>
</execution>
</executions>
</plugin>
It will now run on mvn package