Spark Error - Unsupported class file major version

I ran into this issue when running Jupyter Notebook and Spark using Java 11. I installed and configured for Java 8 using the following steps.

Install Java 8:

$ sudo apt install openjdk-8-jdk

Since I had already installed Java 11, I then set my default Java to version 8 using:

$ sudo update-alternatives --config java

Select Java 8 and then confirm your changes:

$ java -version

Output should be similar to:

openjdk version "1.8.0_191"
OpenJDK Runtime Environment (build 1.8.0_191-8u191-b12-2ubuntu0.18.04.1-b12)
OpenJDK 64-Bit Server VM (build 25.191-b12, mixed mode)

I'm now able to run Spark successfully in Jupyter Notebook. The steps above were based on the following guide: https://www.digitalocean.com/community/tutorials/how-to-install-java-with-apt-on-ubuntu-18-04

I found that adding the spark location through findspark and java8 with os at the beginning of the script the easiest solution:

import findspark
import os
spark_location='/opt/spark-2.4.3/' # Set your own
java8_location= '/usr/lib/jvm/java-8-openjdk-amd64' # Set your own
os.environ['JAVA_HOME'] = java8_location
findspark.init(spark_home=spark_location) 

Edit Spark 3.0 supports Java 11, so you'll need to upgrade

Spark runs on Java 8/11, Scala 2.12, Python 2.7+/3.4+ and R 3.1+. Java 8 prior to version 8u92 support is deprecated as of Spark 3.0.0

---

---

Original answer

Until Spark supports Java 11, or higher (which would be hopefully be mentioned at the latest documentation when it is), you have to add in a flag to set your Java version to Java 8.

As of Spark 2.4.x

Spark runs on Java 8, Python 2.7+/3.4+ and R 3.1+. For the Scala API, Spark 2.4.4 uses Scala 2.12. You will need to use a compatible Scala version (2.12.x)

On Mac/Unix, see asdf-java for installing different Javas

On a Mac, I am able to do this in my .bashrc,

export JAVA_HOME=$(/usr/libexec/java_home -v 1.8)

On Windows, checkout Chocolately, but seriously just use WSL2 or Docker to run Spark.

---

You can also set this in spark-env.sh rather than set the variable for your whole profile.

And, of course, this all means you'll need to install Java 8 in addition to your existing Java 11