I keep getting this error even though I have a 1.6+ version (I have 1.8), and i'm working with IntelliJ.
P.S. I have tried to update both, java jre and java jdk, didn't help!
File > Project Structure > Project Settings > Modules > your Module name > Sources > Language Level > choose the one which you need.
This warning is produced by the Java | Java language level migration aids | Usages of API which isn't available at the configured language level inspection. By default this inspection looks at the language level configured for the project, and warns on any api used that was not available in the JDK version matching the language level. Most likely your project's or module's language level is not configured correctly in the Project Structure settings.
You may also need to ensure that your project has build/release set to the right java version. Without that, you may see an error like this:
Error:java: javacTask: source release 1.8 requires target release 1.8
The way to fix it for maven project is to enable build plugin in your pom file. This SO answer has specifics.
If your project was imported via maven, you can fix the error by adding/editing the maven compiler plugin definition to look like this
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
But if you're collaborating on an open source project, then making such a change will need approval first. If it's denied then you can do what 余智平 suggested. But keep in mind that the setting may be reverted if you some how reimport the project as InteliJ will read project configurations again from the POM.
use below in your pom to set the java version which Intellij will be used(default is 1.5)
<properties>
<maven.compiler.target>1.8</maven.compiler.target>
<maven.compiler.source>1.8</maven.compiler.source>
</properties>
Related
I am having an issue running tests using tycho due to an incorrect dependency resolution that, somehow, is placing the the old Google Collections .jar on the classpath and not the Guava one, despite the fact that at no point in any of my poms do I specify a dependency on collections (only guava).
My unit tests fail due to things like NoSuchMethodError (ImmutableList.copyOf), NoClassDefFoundError (Joiner), which I pretty much narrowed down to 'finding the wrong jar'. These same tests pass when ran manually in Eclipse.
Here is the relevant part of the pom:
<dependencies>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>14.0.1</version>
</dependency>
...
</dependencies>
The phrase 'google collections' appears no where. The only other repository I specify is:
<repositories>
<repository>
<id>helios</id>
<layout>p2</layout>
<url>http://download.eclipse.org/releases/helios</url>
</repository>
</repositories>
My plugin imports 'com.google.common.base' and 'com.google.common.collect' as imported packages. I have my own bundled version of Guava 14 in my workspace for debugging, but in the POM I elect to not use my local module.
I followed Sean Patrick Floyd's answer on this question (JUnit throws java.lang.NoSuchMethodError For com.google.common.collect.Iterables.tryFind), and had my test throw an exception with the location of the .jar that the Iterables class was loaded from. It spat back out:
java.lang.IllegalArgumentException: file:/C:/Documents and Settings/Erika Redmark/.m2/repository/p2/osgi/bundle/com.google.collect/0.8.0.v201102150722/com.google.collect-0.8.0.v201102150722.jar
This is where I am now stuck. This google-collections jar is coming seemingly out of no where, and I don't know how to stop it. As long as it is being resolved, my unit tests will fail. How can I stop Tycho from trying to get the old Google Collections?
Just to clarify, this has not stopped building and deployment; the plugin update site is on an CI platform and we have been able to install the plugin on different Eclipse IDEs, so this issue is only affecting the tests.
Please let me know if additional information is needed.
The plug-in com.google.collect 0.8.0.v201102150722 is part of the Helios p2 repository that you have configured in your POM. This means that this plug-in is part of the target platform and so may be used to resolve dependencies.
If you want to ensure that the bundle is not used, make sure that it is not part of the target platform. In your case, the easiest way to do this is to explicitly remove the plug-in from the target platform:
<plugin>
<groupId>org.eclipse.tycho</groupId>
<artifactId>target-platform-configuration</artifactId>
<version>${tycho-version}</version>
<configuration>
<filters>
<filter>
<type>eclipse-plugin</type>
<id>com.google.collect</id>
<removeAll />
</filter>
</filters>
</configuration>
</plugin>
Next, you need to make sure that the guava plug-in is part of the target platform. You can add an artifact from a Maven repository to the target platform in the following way:
Declare a Maven dependency to the artifact in the dependencies section of the POM. You already have done this correctly.
Set the configuration parameter <pomDependencies> to consider on Tycho's target-platform-configuration plug-in.
Note that this will generally only work if the referenced artifact is already an OSGi bundle. This is the case here: com.google.guava:guava:14.0.1 seems to have all manifest headers needed by OSGi.
This should give you the result you wanted: In the test runtime, guava should now be used to match your com.google.common.* package imports.
And another general remark on declaring dependencies in Tycho: In Tycho, you can only declare dependencies in the PDE source files META-INF/MANIFEST.MF, feature.xml, etc.
The normal Maven-style dependencies declared in the POM do not add dependencies to the project. As explained above, the POM dependencies may only add artifacts to the target platform, i.e. the set of artifacts that may be used by Tycho to resolve the dependencies declared in the PDE source files. So in the end, the POM dependency may become part of the resolved dependencies, but only if the dependency resolver picks it for matching one of the declared dependencies.
by default, tycho will add any p2 artifacts you installed in your local maven repo to the target platform. If bundle com.google.collect exports the package which you import, it may be wired.
To stop tycho from including any locally installed artifacts, you can use -Dtycho.localArtifacts=ignore (or, remove the unwanted bundle from your local maven repo)
See http://wiki.eclipse.org/Tycho/Release_Notes/0.16#Improvements_and_Fixes
I've created a maven project and wanted to change the java compiler version to 1.6 so I added the ff:
<build>
<plugins>
<plugin>
<artifactId>org.apache.maven.plugins</artifactId>
<groupId>maven-compiler-plugin</groupId>
<version>2.3.2</version>
<configuration>
<source>1.6</source>
<target>1.6</target>
</configuration>
</plugin>
</plugins>
</build>
When I run any maven goal in eclipse, it works. But when I run in terminal I got the ff errors:
Project ID: maven-compiler-plugin:org.apache.maven.plugins
Reason: POM 'maven-compiler-plugin:org.apache.maven.plugins' not found in repository: Unable to download the artifact from any repository
maven-compiler-plugin:org.apache.maven.plugins:pom:2.3.2
from the specified remote repositories:
central (http://repo1.maven.org/maven2),
apache.repo (https://repository.apache.org/content/repositories/releases),
jboss.repo.deprecated (https://repository.jboss.org/nexus/content/repositories/deprecated),
Any idea what's causing this issue?
I was able to solved this issue by updating to maven3. But my problem right now is although I specified maven-compiler-plugin version to be 2.4, I'm still seeing 2.3.2 in the log.
Your groupId and artifactId are reversed.
If Eclipse and the command line create different results, then they use different local Maven repositories. The default is in $HOME/.m2/repository/. So the first step is to find out which one (command line or Eclipse) uses a different local cache and why.
The next question is why the download failed. The usual reason is that Maven tried the download and got an error. Maven will remember the error and not try again. To force it to try again, you have to delete the folder $M2_REPO/repository/org/apache/maven/plugins/maven-compiler-plugin/2.3.2/.
Lastly, when you configure 2.4 but see 2.3.2 in the log, then you're either building the wrong project of one of the POMs of your build overwrites the version for the compiler plugin.
To avoid issues like this, use a parent POM where you keep all the versions in dependencyManagement (for dependencies) and pluginManagement (for plugins) elements. That way, you will never have to define a version in a module POM or in other projects which inherit from this one.
After installing maven 3 from a repository and added maven3 home in /etc/environment what I forgot to do is to reboot my machine, after that it worked.
My /etc/environment now looks like:
M3_HOME="/home/edward/java/apache/maven-3.0.4"
MAVEN_HOME="/home/edward/java/apache/maven-3.0.4"
M3="home/edward/java/apache/maven-3.0.4"
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/home/edward/java/apache/maven-3.0.4"
Here's how I uninstalled and install maven 3:
http://czetsuya-tech.blogspot.com/2012/05/how-to-install-maven-3-in-ubuntu-1110.html
My maven reports are working great, all except Checkstyle and test xref. My test source is still being cross referenced at xref and not the test xref. So, when I click on the xref from within a Checkstyle report, I naturally get an error, the file isn't found. If I click on a source file, it works perfectly.
I tried testXrefLocation in the configuration to no avail. Is this by design, or am I missing a configuration?
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-checkstyle-plugin</artifactId>
<configuration>
<enableRulesSummary>false</enableRulesSummary>
<includeTestSourceDirectory>true</includeTestSourceDirectory>
<configLocation>${project.build.directory}/checkstyle.xml</configLocation>
<testXrefLocation>${project.reporting.outputDirectory}/xref-test</testXrefLocation>
</configuration>
</plugin>
mvn clean install site
In my target directory where all this stuff is generated, I have both xref and xref-test. However, my checkstyle reports for my test source code are still linked to target/xref and not target/xref-test.
Also, FYI, I am using a lot of inheritance to reduce the amount of configuration in a single Maven POM. Therefore, this plugin belongs to a parent pom which declares which plugins I want to use for testing. I have another that says I want to generate javadoc and source in addition to the compiled code.
Walter
I actually ended up removing this configuration in favor of using Sonar since it gives me much more information with a nicer UI.
I'm trying to write a pom.xml that will allow me to run a command locally and fetch all dependencies that my jruby Rails app has. I'm seeing two different configs though and I'm not totally sure which to use (as I'm not a java person whatsoever)
First, many Pom's i'm seeing just have a tag under the root of the pom.xml that list all dependencies. This doesn't however have any information about where these are stored etc... so I feel like this isn't what I want (I need to copy them to my rails lib dir)
Second option, I'm seeing in the mvn docs is to use the maven-dependency-plugin, which seems more like what i'm looking for. I assume then that my outputDirectory would be something like lib
So I don't fully understand what the purpose of the first option's dependency list is for. All I want is mvn to copy my jars locally (and then eventually when my CI server does a deploy). Can someone point me in the right direction?
First Option
<project>
<dependencies>
<dependency>
<groupId>commons-lang</groupId>
<artifactId>commons-lang</artifactId>
<version>2.4</version>
</dependency>
</project>
Second Option
<project>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<configuration>
<artifactItems>
<artifactItem>
<groupId>[ groupId ]</groupId>
<artifactId>[ artifactId ]</artifactId>
<version>[ version ]</version>
<type>[ packaging ]</type>
<classifier> [classifier - optional] </classifier>
<overWrite>[ true or false ]</overWrite>
<outputDirectory>[ output directory ]</outputDirectory>
<destFileName>[ filename ]</destFileName>
</artifactItem>
</artifactItems>
<!-- other configurations here -->
</configuration>
</plugin>
</plugins>
</build>
</project>
First, many Pom's i'm seeing just have a tag under the root of the pom.xml that list all dependencies. This doesn't however have any information about where these are stored etc... so I feel like this isn't what I want (I need to copy them to my rails lib dir)
This is the traditional way to declare and use dependencies on a Java project. Dependencies declared under the <dependencies> element are downloaded from a "remote repository" and installed to your "local repository" (in ~/.m2/repository by default) and artifacts are then handled from there. Maven projects (at least the Java ones) don't use a local lib/ folder for their dependencies.
Second option, I'm seeing in the mvn docs is to use the maven-dependency-plugin, which seems more like what i'm looking for. I assume then that my outputDirectory would be something like lib
The maven dependency plugin allows to interact with artifacts and to copy/unpack them from the local or remote repositories to a specified location. So it can be used to get some dependencies and copy them in lets say a lib/ directory indeed. Actually, it has several goals allowing to do this:
dependency:copy takes a list of artifacts defined in the plugin
configuration section and copies them
to a specified location, renaming them
or stripping the version if desired.
This goal can resolve the artifacts
from remote repositories if they don't
exist in local.
dependency:copy-dependencies takes the list of project direct
dependencies and optionally transitive
dependencies and copies them to a
specified location, stripping the
version if desired. This goal can also
be run from the command line.
The first goal would use the setup you described in your second option. The second goal would use the standard project dependencies that you described in your first option. Both approaches would work.
The problem here is that I don't know exactly what a JRuby Rails app is, what the development workflow is, how to build such an app, etc so I don't know exactly what you need to do and, consequently, what would be the best way to implement that with Maven.
So I googled a bit and found this post that shows another approach based on OS commands (using the maven exec plugin) and has a complete pom.xml doing some other things. Maybe you should look at it and use it as a starting point instead of reinventing everything. This is my suggestion actually.
I'm looking for a Maven2 reporting plugin for Simian and the closest thing to such a reporting I found is this. The problem is, the documentation for it appears to be for Maven 1 instead. Why is a Maven 1 plugin stored in a Maven 2 repository? I suppose that means I can use it... but how to use? The site mentions reporting but if I don't have a src/main/site, does that mean I can't use it? I was kinda hoping for something like mvn simian:simian similar to mvn checkstyle:checkstyle and mvn pmd:pmd. I don't want to generate site just for the reports. Sites take too long to generate when all I want is a quite xml report.
The Simian plugin listed on central is actually for Maven 1 (if you inspect the contents you'll see a project.xml and a plugin.jelly). So that explains why it doesn't work. This is rubbish and should be removed in my opinion.
As far as I can make out there isn't a publically available Maven 2 plugin, this may have something to do with the licence (Simian isn't open source).
As an alternative, have a look at PMD's CPD plugin, it may not be as fully featured as simian but I know it works in a Maven 2 build and detects copypasta pretty well.
To configure PMD, add something like the following to your POM:
<reporting>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-pmd-plugin</artifactId>
<version>2.4</version>
</plugin>
</plugins>
</reporting>