Java Runtime only recognizes class file versions up to 52.0 even when java 11 is installed

Question

I can't run my java servelet on my tomcat 9.0.12 server because it can't handle the class version. I get following error:

Error: MyClass been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0 (unable to load class

I compiled my code with java 11:

<plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.0</version>
                <configuration>
                    <source>11</source>
                    <target>11</target>
                </configuration>
            </plugin>

when I type in : java -version in my terminal I get:

java version "11.0.2" 2019-01-15 LTS
Java(TM) SE Runtime Environment 18.9 (build 11.0.2+9-LTS)
Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.2+9-LTS, mixed mode)

and for javac -version

javac 11.0.2

Why can't the Runtime handle v55.0? java 11 == v55.0?!

Solution

The problem is not tomcat but the JVM which runs tomcat.

I don't know how you start tomcat, but you should start it with a JDK 11.

If you use eclipse you should check the Server Runtime.

For other IDEs or starting it from OS directly (as an application or a service or whatever), you should check the JAVA_HOME and the PATH.

Comments

[JensW]

Version 52.00 stands for Java 8 I think, so somewhere you're using a JRE 1.8 I think. Check if project menu > properties > java compiler > Compiler and compliance level show 1.11 or 1.8

[Gimby]

The simplest answer is that Tomcat is running on Java 8.

[Dennis Adler]

yes you're right tomcat was still using java1.8. I changed my JAVA_HOME to the new version Thank you