when we are trying to run mvn eclipse:eclipse from command line, we are getting following error:
Internal error in the plugin manager executing goal
'org.apache.maven.plugins:maven-eclipse-plugin:2.6:eclipse': Unable to
load the mojo
'org.apache.maven.plugins:maven-eclipse-plugin:2.6:eclipse' in the
plugin 'org.apache.maven.plugins:maven-eclipse-plugin'. A required
class is missing:
org/codehaus/plexus/resource/loader/ResourceNotFoundException
any help to solve this is appreciated.
Thanks,
The Apache Maven Eclipse Plugin is RETIRED:
Users are advised to use m2e, the Eclipse Maven Integration instead of this plugin, as it can more closely resemble the actual build and runtime classpaths as described in the project pom.xml - among other advantages.
Related
What are the possible causes of a "java.lang.Error: Unresolved compilation problem"?
Additional information:
I have seen this after copying a set of updated JAR files from a build on top of the existing JARs and restarting the application. The JARs are built using a Maven build process.
I would expect to see LinkageErrors or ClassNotFound errors if interfaces changed. The above error hints at some lower level problem.
A clean rebuild and redeployment fixed the problem. Could this error indicate a corrupted JAR?
(rewritten 2015-07-28)
Summary: Eclipse had compiled some or all of the classes, and its compiler is more tolerant of errors.
Long explanation:
The default behavior of Eclipse when compiling code with errors in it, is to generate byte code throwing the exception you see, allowing the program to be run. This is possible as Eclipse uses its own built-in compiler, instead of javac from the JDK which Apache Maven uses, and which fails the compilation completely for errors. If you use Eclipse on a Maven project which you are also working with using the command line mvn command, this may happen.
The cure is to fix the errors and recompile, before running again.
The setting is marked with a red box in this screendump:
try to clean the eclipse project
you just try to clean maven by command
mvn clean
and after that following command
mvn eclipse:clean eclipse:eclipse
and rebuild your project....
Your compiled classes may need to be recompiled from the source with the new jars.
Try running "mvn clean" and then rebuild
The major part is correctly answered by Thorbjørn Ravn Andersen.
This answer tries to shed light on the remaining question: how could the class file with errors end up in the jar?
Each build (Maven & javac or Eclipse) signals in its specific way when it hits a compile error, and will refuse to create a Jar file from it (or at least prominently alert you). The most likely cause for silently getting class files with errors into a jar is by concurrent operation of Maven and Eclipse.
If you have Eclipse open while running a mvn build, you should disable Project > Build Automatically until mvn completes.
EDIT:
Let's try to split the riddle into three parts:
(1) What is the meaning of "java.lang.Error: Unresolved compilation
problem"
This has been explained by Thorbjørn Ravn Andersen. There is no doubt that Eclipse found an error at compile time.
(2) How can an eclipse-compiled class file end up in jar file created
by maven (assuming maven is not configured to used ecj for
compilation)?
This could happen either by invoking Maven with no or incomplete cleaning. Or, an automatic Eclipse build could react to changes in the filesystem (done by Maven) and re-compile a class, before Maven proceeds to collect class files into the jar (this is what I meant by "concurrent operation" in my original answer).
(3) How come there is a compile error, but mvn clean succeeds?
Again several possibilities: (a) compilers don't agree whether or not the source code is legal, or (b) Eclipse compiles with broken settings like incomplete classpath, wrong Java compliance etc. Either way a sequence of refresh and clean build in Eclipse should surface the problem.
I had this error when I used a launch configuration that had an invalid classpath. In my case, I had a project that initially used Maven and thus a launch configuration had a Maven classpath element in it. I had later changed the project to use Gradle and removed the Maven classpath from the project's classpath, but the launch configuration still used it. I got this error trying to run it. Cleaning and rebuilding the project did not resolve this error. Instead, edit the launch configuration, remove the project classpath element, then add the project back to the User Entries in the classpath.
I got this error multiple times and struggled to work out. Finally, I removed the run configuration and re-added the default entries. It worked beautifully.
Just try to include package name in eclipse in case if you forgot it
Import all packages before using it, EX: import java.util.Scanner before using Scanner class.
These improvements might work and it will not give Java: Unresolved compilation problem anymore.
Also make sure to check compiler compliance level and selected jdk version is same
As a weird case, I encountered such an exception where the exception message (unresolved compilation bla bla) was hardcoded inside of generated class' itself. Decompiling the class revealed this.
I had the same issue using the visual studio Code. The root cause was backup java file was left in the same directory.
Removed the backup java file
When the build failed, selected the Fix it, it cleaned up the cache and restarted the workSpace.
As shown in the screenshot there is a dependency of the dl4j-0.4-examples project that is unable to be loaded by intellij.
Unable to get dependency information: Unable to read the metadata file
for artifact 'com.github.jai-imageio-core.jar': Invalid JDK version in
profile "java8-and-higher': Unbounded range [1.8
A similar problem resolved in this question
https://github.com/google/gson/issues/596
as quick fix open the pom file at your local repository and add ')'
and should looks like
91 [1.8,)
save and execute again
But in this case there is no jdk tag: so that approach can not be used.
Has anyone found a workaround to load this project into intellij?
The owners of the project have recognized this as an issue. If you would like to follow along here is the bug tracker:
https://github.com/deeplearning4j/dl4j-0.4-examples/issues/76
Update 2/28/16: The resolution: I needed to do
brew switch maven 3.3.9
There were multiple versions of maven installed on my machine but I did not know about brew switch. So some ways maven was working without doing the switch - but for this project a completely clean maven installation was required.
I'm trying to create an executable jar from IntelliJ.
First I got the Java Security Exception and I changed sqljdbc4-4.0 to unsigned. First problem solved.
Then I got Manifest not found. Added META-INF dir to output. Second problem solved.
Next I got the BeanCreationException (unsolved):
Caused by: org.springframework.beans.factory.BeanCreationException: Cannot determine embedded database driver class for database type NONE. If you want an embedded database please put a supported one on the classpath.
In IntelliJ it is working.
I think the resources are not in the output. (application.properties, ...)
In which way do I add the resources or where are they stored in the jar.
I'm using gradle and on the spring boot homepage are only instructions for maven.
You should use spring-boot-maven-plugin or spring-boot-gradle-plugin, depending on your preferred build system.
EDIT:
Just run ./gradlew build
I suggest to dive into this getting started guide. It clarifies a lot of stuff for beginners.
A typical Spring boot project is a Maven project or a Gradle-Project (I only know how to do it with Maven, for Gradle see [luboskrnacs answer][1]). So you just need to run the maven targetpackageand pick the jar form the (created)target` folder
use a shell, go to the project root directory (where the pom.xml file is) and type
mvn clean package
cd target
the there is the xxx.jar file.
I'm rather new to Maven and I often find myself wanting to see what's actually there in terms of goals.
So, is there a command which lists all available goals for e.g. a given prefix?
Since Maven is an open system of plugins, the best answer is probably "Google" ;-). If you mean all build lifecycle phases, they are static, and can be found at http://maven.apache.org/guides/introduction/introduction-to-the-lifecycle.html and at other places.
Then, for a given plugin, the help plugin can be used to get the possible goals and all their parameters:
mvn help:describe -DgroupId=org.apache.maven.plugins \
-DartifactId=maven-war-plugin \
-Ddetail=true
But this doesn't really answer your question, especially the "for a given prefix" part. For this, the best solution might be to use **auto completion with BASH (**not sure it will be exhaustive though). See for example the Guide to Maven 2.x auto completion using BASH. To get bash completion working under Windows, you'll need CYGWIN. See Maven Tab Auto Completion in Bash for detailed setup steps (and a "better" working auto completion script).
A shorter way
As an alternative, you can also use the -Dplugin parameter to display the list of available goals.
mvn help:describe -Dplugin=org.apache.maven.plugins:maven-war-plugin\
-Ddetail=true
See Maven help plugin.
More and more Maven plugins propose an help goal as alternative to the verbose
mvn help:describe command.
You can read from the Maven doc:
Recent Maven plugins have generally an help goal to have in the
command line the description of the plugin, with their parameters and
types
That is really more natural and pleasant to use.
It works of course for Maven core plugins.
Some examples :
to list goals of the dependency plugin :
mvn dependency:help
to have detail about the javadoc goal of the javadoc plugin :
mvn javadoc:help -Ddetail -Dgoal=javadoc
And it works also for third party plugins.
For example, to list goals of the spring-boot-maven-plugin :
mvn org.springframework.boot:spring-boot:help
[INFO] Spring Boot Maven Plugin 2.0.0.RELEASE Spring Boot Maven
Plugin
This plugin has 6 goals:
spring-boot:build-info
Generate a build-info.properties file based the content of the
current MavenProject.
spring-boot:help
Display help information on spring-boot-maven-plugin. Call mvn
spring-boot:help -Ddetail=true -Dgoal= to display
parameter details.
spring-boot:repackage
Repackages existing JAR and WAR archives so that they can be
executed from the command line using java -jar. With layout=NONE can
also be used simply to package a JAR with nested dependencies (and
no main class, so not executable).
.....
Or to get detailed information about the build goal of the dockerfile-maven-plugin :
mvn com.spotify:dockerfile-maven-plugin:help -Ddetail -Dgoal=build
[INFO] Dockerfile Maven Plugin 1.3.6
Adds support for building Dockerfiles in Maven
dockerfile:build
Available parameters:
- archive
The archive configuration to use for the Docker info JAR. This can be used
to embed additional information in the JAR.
....
You could note that the syntax to get a detailed output of the help and to focus on a specific goal (-Ddetail -Dgoal=myGoal) is exactly the same as this used for the core maven plugins.
Of course some esoteric plugins may not provide the help goal but in most of well designed plugins this is present.
I'm trying to create a new plugin to package my latest project. I'm trying to have this plugin depend on the maven-dependency-plugin to copy all my projects dependencies.
I've added this dependency to my plugin's pom, but I can't get it to execute.
I have this annotation in my plugins main Mojo:
#execute goal="org.apache.maven.plugins:maven-dependency-plugin:copy"
I've tried a few other names for the goal, like dependency:copy and just copy but they all end with a message saying that the required goal was not found in my plugin. What am I doing wrong?
Secondary to this is where to I provide configuration info for the dependency plugin?
Use the Maven Mojo executor by Don Brown of Atlassian fame to run any other arbitrary plugin.
The Mojo Executor provides a way to to
execute other Mojos (plugins) within a
Maven 2 plugin, allowing you to easily
create Maven 2 plugins that are
composed of other plugins.
Have you tried to create your own packaging type? Then you can define your own lifecycle mapping, i.e. bind goals to phases. In this case you can bind the dependency:copy-dependencies goal to your packaging phase and you don't have to wrap the goal into your own Mojo.
See also: How do I create a new packaging type for Maven?