Unable to compile simple Java 10 / Java 11 project with Maven

As of 30Jul, 2018 to fix the above issue, one can configure the java version used within maven to any up to JDK/11 and make use of the maven-compiler-plugin:3.8.0 to specify a release of either 9,10,11 without any explicit dependencies.

<plugin>    <groupId>org.apache.maven.plugins</groupId>    <artifactId>maven-compiler-plugin</artifactId>    <version>3.8.0</version>    <configuration>        <release>11</release>  <!--or <release>10</release>-->    </configuration></plugin>

Note:- The default value for source/target has been lifted from 1.5 to 1.6 with this version. -- release notes.

Edit [30.12.2018]

In fact, you can make use of the same version of maven-compiler-plugin while compiling the code against JDK/12 as well.

More details and a sample configuration in how to Compile and execute a JDK preview feature with Maven.

UPDATE

The answer is now obsolete. See this answer.

maven-compiler-plugin depends on the old version of ASM which does not support Java 10 (and Java 11) yet. However, it is possible to explicitly specify the right version of ASM:

<plugin>    <groupId>org.apache.maven.plugins</groupId>    <artifactId>maven-compiler-plugin</artifactId>    <version>3.7.0</version>    <configuration>        <release>10</release>    </configuration>    <dependencies>        <dependency>            <groupId>org.ow2.asm</groupId>            <artifactId>asm</artifactId>            <version>6.2</version> <!-- Use newer version of ASM -->        </dependency>    </dependencies></plugin>

You can find the latest at https://search.maven.org/search?q=g:org.ow2.asm%20AND%20a:asm&core=gav

It might not exactly be the same error, but I had a similar one.

Check Maven Java Version

Since Maven is also runnig with Java, check first with which version your Maven is running on:

mvn --version | grep -i java 

It returns:

Java version 1.8.0_151, vendor: Oracle Corporation, runtime: C:\tools\jdk\openjdk1.8

Incompatible version

Here above my maven is running with Java Version 1.8.0_151.So even if I specify maven to compile with Java 11:

<properties>    <java.version>11</java.version>    <maven.compiler.source>${java.version}</maven.compiler.source>    <maven.compiler.target>${java.version}</maven.compiler.target></properties>

It will logically print out this error:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.0:compile (default-compile) on project efa-example-commons-task: Fatal error compiling: invalid target release: 11 -> [Help 1]

How to set specific java version to Maven

The logical thing to do is to set a higher Java Version to Maven (e.g. Java version 11 instead 1.8).

Maven make use of the environment variable JAVA_HOME to find the Java Version to run. So change this variable to the JDK you want to compile against (e.g. OpenJDK 11).

Sanity check

Then run again mvn --version to make sure the configuration has been taken care of:

mvn --version | grep -i java

yields

Java version: 11.0.2, vendor: Oracle Corporation, runtime: C:\tools\jdk\openjdk11

Which is much better and correct to compile code written with the Java 11 specifications.