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Eclipse Kepler is unable to set the Java jdk 1.8 when maven project is updated

Installed java version is 1.8, while selecting this version in pom.xml and updating the maven project,it automatically jumps from 1.8 to 1.4, due to which I am unable to have Lambda expression specific code.
I am using eclipse kepler.
Any idea what is happening here ?

Add something similar to this to your pom. You might have to tweak the plug in version.
<project>
[...]
<build>
[...]
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.3</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
[...]
</build>
[...]
</project>
Apologies I'm on mobile and the editor sucks for code formatting.
Edit: As noted in the accepted answer you also need to enable Java 8 support in Kepler.

With the help of Hogler's comment above I am able to reswolve this issue
Just did this :
https://wiki.eclipse.org/JDT/Eclipse_Java_8_Support_For_Kepler

Incremental java compile with maven (like Eclipse does)

I want to use maven to build projects in which there are unresolved compilation problems.
The main purpose is package and deploy or run aplications using some kind of stubs for classes that contains compilation errors, like I understand that Eclipse does (thanks to JDT Core).
I configurate maven java compiler plugin following Apache Maven documentation at Using Non-Javac compiler to use Eclipse compiler. Thinking that maybe should set some arguments to modify the compiler/builder behaivor I was reading Help Eclipse - Compiling Java code but I don't realize which compiler/builder option or combination of these does the trick.
So far, the next configuration of the maven java compiler plugins compile using the eclipse compiler and package the application including generated .class (jvm bytecode) only for java classes without compilation errors. To get this behaivor it just require use the eclipse compiler (see compilerId and the dependency) and set failOnError=false.
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<compilerId>eclipse</compilerId>
<source>1.7</source>
<target>1.7</target>
<optimize>true</optimize>
<showWarnings>true</showWarnings>
<showDeprecation>true</showDeprecation>
<failOnError>false</failOnError>
<compilerArguments>
<org.eclipse.jdt.core.compiler.problem.fatalOptionalError>disabled</org.eclipse.jdt.core.compiler.problem.fatalOptionalError>
<org.eclipse.jdt.core.compiler.problem.forbiddenReference>ignore</org.eclipse.jdt.core.compiler.problem.forbiddenReference>
</compilerArguments>
</configuration>
<dependencies>
<dependency>
<groupId>org.codehaus.plexus</groupId>
<artifactId>plexus-compiler-eclipse</artifactId>
<version>2.3</version>
</dependency>
</dependencies>
</plugin>
With this configuration I could run java application as long as the execution doesn't use classes not included for compilation errors (because the stubs aren't generated) but on a Java EE container, the classloading will faild so the application can never be deployed.
I appreciate any help on this.

Just for share the solution, at that moment I just replace the plexus-compiler-eclipse with tycho-compiler-jdt to get the desire behaivor.
The proceedOnError parameter indicates that it must keep compiling in spite of errors, dumping class files with problem methods or problem types how to deal with the compilation errors.
Next is the final configuration sample.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<compilerId>jdt</compilerId>
<source>1.7</source>
<target>1.7</target>
<optimize>true</optimize>
<failOnError>false</failOnError>
<compilerArguments>
<proceedOnError/>
</compilerArguments>
</configuration>
<dependencies>
<dependency>
<groupId>org.eclipse.tycho</groupId>
<artifactId>tycho-compiler-jdt</artifactId>
<version>0.22.0</version>
</dependency>
</dependencies>
</plugin>
There is more plugin configuration examples in the Tycho FAQ.
And the possible compiler arguments are described in section Using the batch compiler of the Java development user guide (Eclipse Help site).

Arguments for eclipse compiler in Maven

In the Eclipse Compiler for Java standalone, I am able to log in XML the compilation info via a command-line atribute, as in this stub:
java -jar ecj-4.3.2.jar -log compile.xml <classpath,files>
However, when I use maven-compiler-plugin with plexus-compiler-eclipse, it seems I am unable to pass this argument to the compiler, and I am not sure the cause of this, whether the plugin's compiler is another one, it doesn't spawn new processes (i even tried the executable parameter), or other reason.
Here is the pom.xml section:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<compilerId>eclipse</compilerId>
<forceJavacCompilerUse>true</forceJavacCompilerUse>
<!--<compilerArgument> -log compile.xml </compilerArgument>-->
<compilerArgs>
<arg>-log</arg>
<arg>compile.xml</arg>
</compilerArgs>
<fork>true</fork>
<verbose>true</verbose>
<showDeprecation>true</showDeprecation>
<showWarnings>true</showWarnings>
</configuration>
<dependencies>
<dependency>
<groupId>org.codehaus.plexus</groupId>
<artifactId>plexus-compiler-eclipse</artifactId>
<version>2.3</version>
</dependency>
</dependencies>
</plugin>

The eclipse implementation is plexus-compiler-eclipse, it doesn't accept fork argument, as it uses the internal jvm. So, it can only accept jvm options like MAVEN_OPTS.
However, the default implementation is plexus-compiler-javac, which supports custom executable. The workaround may like this: set fork to true, and specify the executable.
For wraper in bash, you can visit here: https://stackoverflow.com/a/37971000/3289354

How can I switch the bytecode target level in IntelliJ using Maven 3 profiles

I am using maven profiles to switch between two "setups" in Intelli J. How can I switch the bytecode target level? That is: I want to change the following setting in compiler.xml
<bytecodeTargetLevel>
<module name="finmath-lib" target="1.6" />
</bytecodeTargetLevel>
Note: I tried to perform this via the following part in the respective Maven 3 profile
<profile>
<id>java-8</id>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
</profile>
but this does not work!
Note: The pom.xml etc. belongs to the finmath lib project, and if you are interested, it can be found at www.finmath.net

I am using IntelliJ IDEA 14.1.3 and it works with following config ...
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.3</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
Hope this is helpful. Thanks!

The problem is that you want to change it to 1.8.
I've tried to switch IntelliJ's compiler version between 1.7 and 1.6 or 1.5 using Maven profile successfully.
However when you want to change it to 1.8, the config will be ignored.
I don't know whether this is maven's problem or Intellj's.
It seems that the JDK 1.8 is not well supported now, which is understandable.

You can open the Maven Projects tool window in IntelliJ and select the profile you want to use from the list.

In IntelliJ 13, File > Project Structure, set the Project language level to 8.0.

Is there a way to make maven build class files with UTF-8 without using the external JAVA_TOOL_OPTIONS?

I don't want to be dependable on a external environment variable to force maven to build my classes with UTF-8. On Mac, I was getting all sorts of problems when building with maven. Only the option below solved the problem:
export JAVA_TOOL_OPTIONS=-Dfile.encoding=UTF-8
mvn clean install
However I am distributing my project and it does NOT make sense to rely on the user to set this environment variable to build the project correctly.
Tried everything as described here: enabling UTF-8 encoding for clojure source files
Anyone has a light on that awesome Maven issue?

#Joop Eggen gave the right answer here: https://stackoverflow.com/a/10367745/962872
It is not enough to define that property. You MUST pass it inside the appropriate plugins. It won't go by magic inside there.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>...</version>
<configuration>
<source>1.6</source>
<target>1.6</target>
<encoding>${project.build.sourceEncoding}</encoding>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<version>...</version>
<configuration>
<encoding>${project.build.sourceEncoding}</encoding>
</configuration>
</plugin>
...
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

Yes there is, define
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

I was running into this problem, but only when running the compile from Emacs. I could not change the project's poms. What worked for me was to put the following in ~/.mavenrc
LANG=en_US.UTF-8