Spring: Class File Has Wrong Version 61.0, Should Be 55.0

This error typically occurs when you are trying to run a Java application compiled with a higher version of Java than the one you have installed. In this case, it seems that you are trying to run a Spring application compiled with Java version 11 (version 61.0), but you have Java version 9 (version 55.0) installed.

To fix this issue, you have a couple of options:

  1. Upgrade your Java version: The easiest solution is to upgrade your Java version to a higher version that is compatible with your application. In this case, you can upgrade from Java 9 to Java 11 or higher.

  2. Downgrade your application’s Java version: If upgrading Java is not an option, you can try to recompile your Spring application with a lower Java version. This means modifying your project configuration (e.g., pom.xml for Maven or build.gradle for Gradle) to specify a lower Java version target.

For Maven, add the following configuration to your pom.xml file:

<properties>
    <maven.compiler.source>9</maven.compiler.source>
    <maven.compiler.target>9</maven.compiler.target>
</properties>

For Gradle, add the following configuration to your build.gradle file:

compileJava {
    sourceCompatibility = 1.9
    targetCompatibility = 1.9
}

After making these changes, recompile your application and try running it again.

Note: It’s generally recommended to use the latest stable version of Java for better performance, security, and bug fixes. So, if possible, upgrading your Java version would be the better long-term solution.

About the Author Rex

I'm a passionate tech blogger with an insatiable love for programming! From my early days tinkering with code, I've delved into web dev, mobile apps, and AI. Sharing insights and tutorials with the world is my joy, connecting me to a global community of like-minded tech enthusiasts. Python holds a special place in my heart, but I embrace all challenges. Constantly learning, I attend tech conferences, contribute to open-source projects, and engage in code review sessions. My ultimate goal is to inspire the next generation of developers and contribute positively to the ever-evolving tech landscape. Let's code together!