UnsupportedClassVersionError: has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version (..)up to 52.0

Question

I'm trying to launch the jar file I've builded for my Spring Boot project. First I did:

mvn clean package spring-boot:repackage

then I've tried to launch the jar file, and I had the following error:

Exception in thread "main" java.lang.UnsupportedClassVersionError: it/sysdata/helios_backend_admin/HeliosAdminBackendApplication has 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 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(Unknown Source) at java.security.SecureClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.access$100(Unknown Source) at java.net.URLClassLoader$1.run(Unknown Source) at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at org.springframework.boot.loader.LaunchedURLClassLoader.loadClass(LaunchedURLClassLoader.java:93) at java.lang.ClassLoader.loadClass(Unknown Source) at org.s pringframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:46) at org.springframework.boot.loader.Launcher.launch(Launcher.java:87) at org.springframework.boot.loader.Launcher.launch(Launcher.java:50) at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:51)

I've checked and java version is 11 everywhere (at least from what I saw). This is the pom:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.2.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    <groupId>it.sysdata</groupId>
    <artifactId>helios_backend_admin</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>helios-admin-backend</name>
        <packaging>jar</packaging>
    <description>Helios Backend for Dashboard admin</description>

    <properties>
        <java.version>11</java.version>
        <flowable.version>6.4.1</flowable.version>
        <swagger.version>2.9.2</swagger.version>
        <jwt.version>0.9.1</jwt.version>
        <cron4j.version>2.2.5</cron4j.version>  
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
        </dependency>  

        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>


        <!-- Flowable -->
        <dependency>
            <groupId>org.flowable</groupId>
            <artifactId>flowable-spring-boot-starter-process</artifactId>
            <version>${flowable.version}</version>
        </dependency>
        <dependency>
            <groupId>org.flowable</groupId>
            <artifactId>flowable-http</artifactId>
            <version>${flowable.version}</version>
        </dependency>  
        <!-- Swagger -->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>${swagger.version}</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>${swagger.version}</version>
        </dependency>
        <!-- JWT -->
        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>${jwt.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-cache</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>



        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.mongodb</groupId>
            <artifactId>mongo-java-driver</artifactId>
            <version>3.10.1</version>
        </dependency>

        <dependency>
            <groupId>it.sauronsoftware.cron4j</groupId>
            <artifactId>cron4j</artifactId>
            <version>${cron4j.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
        </dependency>
    </dependencies>
    <build>
        <finalName>${artifactId}</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                <source>11</source>
                <target>11</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

These are my settings under Project Properties -> Java Compiler -> JDK Compliance :

Then in Window-> Preferences -> Installed JREs :

UPDATE

Are these settings ok?

Answer 1

The real problem was, you built classes before by some upgraded version of JDK than what you currently have.

I too faced a similar issue, which I solved in Eclipse by following steps:

Project Properties (Alt + EnterKey) -> Java Build Path -> "Libraries" section -> 
classpath -> select "JRE System Library" -> Edit -> Execution environment from "JRE System Library" window ->
 Select the exact JDK version you currently have -> Apply -> Apply & Close.

Answer 2

Can you try to add the below maven compiler plugin and check.

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

run the maven and build the jar and try to run.

Answer 3

我通过设置 JAVA_HOME 环境变量将其指向我机器上的 jdk12 目录来修复。

Answer 4

I had similar issues running mvn org.springframework.boot:spring-boot-maven-plugin:run on the command line. It turns out the plugin version was upgraded to something that no longer supports the version of java I was running ( java 11 ). Here is the ERROR I saw:

[ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:3.0.0-M1:run (default-cli) on project PROJECT_NAME: Execution default-cli of goal org.springframework.boot:spring-boot-maven-plugin:3.0.0-M1:run failed: Unable to load the mojo 'run' in the plugin 'org.springframework.boot:spring-boot-maven-plugin:3.0.0-M1' due to an API incompatibility: org.codehaus.plexus.component.repository.exception.ComponentLookupException: org/springframework/boot/maven/RunMojo has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 55.0

I was able to fix this by specifying the version in the command line mvn org.springframework.boot:spring-boot-maven-plugin:2.6.3:run ( notice :2.6.3 )

Answer 5

只需找到正确的 java JDK 并安装它，在你的情况下（55.0 ~ JDK 11）这应该可以工作，至少对我来说。

Answer 6

In my case, there was a wrong JAVA_HOME setup,
and for me worked the following steps:

1. Go to Environment Variables
   
2. Click Edit when JAVA_HOME is selected
   
3. Select the directory where your desired jdk is instaled

This might help to select the correct Java version:

• Java 1.2 uses major version 46
• Java 1.3 uses major version 47
• Java 1.4 uses major version 48
• Java 5 uses major version 49
• Java 6 uses major version 50
• Java 7 uses major version 51
• Java 8 uses major version 52
• Java 9 uses major version 53
• Java 10 uses major version 54
• Java 11 uses major version 55
• Java 12 uses major version 56
• Java 13 uses major version 57
• Java 14 uses major version 58
• Java 15 uses major version 59
• Java 16 uses major version 60
• Java 17 uses major version 61
• Java 18 uses major version 62
• Java 19 uses major version 63

Answer 7

After configuring the version of the compiler to 1.8 (your required version), try the older version of spring boot currently it is 3.0.0 by default but you can try 2.7.6 instead.

enter image description here

Answer 8

Since you did not specift plugin version in pom.xml file, it will always go for the latest version. Which is 3.0.0 as of 24 Nov 2022. And it requires Java 17 at least.

So, if your project is lower than Java 17, it wont work.

What I suggest is please use the plugin with the same version of your java project. And specify it in pom.xml.

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>your projects java version here.</version>
</plugin>