Introduction

Recently, I was upgrading my Java version in one of the repositories and I came across this issue. I was using maven for building this project. In my pom.xml file, I simply declared target as Java version 17 and I came across this error.

This is what it looks like in my pom.xml file.

1<properties>
2    <maven.compiler.source>17</maven.compiler.source>
3    <maven.compiler.target>17</maven.compiler.target>
4</properties>

Problem

After changing this to 17, when I run my test cases using mvn clean test, I get below error.

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.11.0:compile
 (default-compile) on project hello-java: 
 Fatal error compiling: invalid target release: 17 -> [Help 1]

It says invalid target release: 17 for some reason. When I look at my Java version, I see that I have Java 17.

java -version
openjdk version "17.0.10" 2024-01-16
OpenJDK Runtime Environment Temurin-17.0.10+7 (build 17.0.10+7)
OpenJDK 64-Bit Server VM Temurin-17.0.10+7 (build 17.0.10+7, mixed mode)

When I look at mvn -version, it’s using Java 11. So, when you execute mvn commands, it’s using Java version 11 to compile the code.

mvn -version
Apache Maven 3.9.6 (bc0240f3c744dd6b6ec2920b3cd08dcc295161ae)
Maven home: /opt/homebrew/Cellar/maven/3.9.6/libexec
Java version: 11.0.14, vendor: Eclipse Adoptium, runtime: /Library/Java/JavaVirtualMachines/temurin-11.jdk/Contents/Home
Default locale: en_US, platform encoding: UTF-8
OS name: "mac os x", version: "14.4.1", arch: "x86_64", family: "mac"

This is because I had JAVA_HOME variable pointing to Java version 11.

echo $JAVA_HOME
/Library/Java/JavaVirtualMachines/temurin-11.jdk/Contents/Home

Solution

Now, in my case, I use multiple java versions for different projects. If you’re just using single Java version, you can change the JAVA_HOME environment variable in your ~/.bashrc or ~/.zshrc file depending on which shell you’re using. Just add a line like this pointing to Java home directory.

1export JAVA_HOME="/Library/Java/JavaVirtualMachinestemurin-17.0.10/Contents/Home"

Restart your shell session or just run, source ~/.bashrc or source ~/.zshrc to apply new changes to take effect.

Setup using libexec

You could use something like this your rc file and it will set up correct Java home location depending on the version if it’s able to find that version in your system.

1export JAVA_HOME=$(/usr/libexec/java_home -v 17)

Set up using alias

In my case, I have set up Java using alias, because even for same version, I may have different Java providers. so, I prefer to keep the exact location where my java home is located. In my ~/.bashrc file, it looks like this.

1alias j8="export JAVA_HOME=\"/Library/Java/JavaVirtualMachines/jdk1.8.0_202.jdk/Contents/Home\""
2alias j11="export JAVA_HOME=\"/Library/Java/JavaVirtualMachines/temurin-11.jdk/Contents/Home\""
3alias j17="export JAVA_HOME=\"/Library/Java/JavaVirtualMachines/temurin-17.0.10/Contents/Home\""

This allows me to change java version using commands like j17 or j11 etc.

After setting up correct java version to 17, you can verify your java version and what specific Java version maven is using.

echo $JAVA_HOME
/Library/Java/JavaVirtualMachines/temurin-17.0.10/Contents/Home

mvn -version
Apache Maven 3.9.6 (bc0240f3c744dd6b6ec2920b3cd08dcc295161ae)
Maven home: /opt/homebrew/Cellar/maven/3.9.6/libexec
Java version: 17.0.10, vendor: Eclipse Adoptium, runtime: /Library/Java/JavaVirtualMachines/temurin-17.0.10/Contents/Home
Default locale: en_US, platform encoding: UTF-8
OS name: "mac os x", version: "14.4.1", arch: "aarch64", family: "mac"