Spring Boot项目因Java版本不兼容无法启动，求助排查解决

Spring Boot项目使用spring-boot-starter-parent 3.0.1，指定Java 17，但启动失败，抛出UnsupportedClassVersionError异常。

pom.xml配置 #

<?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 https://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>3.0.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.csmtech</groupId>
    <artifactId>ExcelDataBase</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>ExcelDataBase</name>
    <description>Excel To DB Convert</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
        </dependency>
        <dependency>
            <groupId>com.itextpdf</groupId>
            <artifactId>itextpdf</artifactId>
            <version>5.5.13</version>
        </dependency>

        <dependency>
            <groupId>com.itextpdf</groupId>
            <artifactId>html2pdf</artifactId>
            <version>3.0.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>4.1.0</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

异常信息 #

Exception in thread "main" java.lang.UnsupportedClassVersionError: org/springframework/boot/SpringApplication 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 59.0
    at java.base/java.lang.ClassLoader.defineClass1(Native Method)
    at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1016)
    at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:151)
    at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(BuiltinClassLoader.java:825)
    at java.base/jdk.internal.loader.BuiltinClassLoader.findClassOnClassPathOrNull(BuiltinClassLoader.java:723)
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOr…

异常核心原因：org.springframework.boot.SpringApplication由Java 17（类文件版本61.0）编译，但当前运行环境仅支持到Java 15（类文件版本59.0），存在版本不兼容问题。

• 检查并升级本地JDK版本：打开终端执行java -version和javac -version，确认输出版本是否为Java 17。若不是，下载安装Java 17并配置环境变量，将其设为系统默认JDK。
• 配置IDE的JDK版本：
  • IntelliJ IDEA：进入File > Project Structure，在Project Settings > Project中设置SDK为Java 17；再进入Settings > Build, Execution, Deployment > Compiler > Java Compiler，将Project bytecode version及各模块的Target bytecode version设为17。
  • Eclipse：进入Window > Preferences > Java > Installed JREs，添加并选中Java 17；再进入Project Properties > Java Build Path，修改JRE System Library为Java 17；最后进入Project Properties > Java Compiler，勾选Use compliance from execution environment 'JavaSE-17' on the 'Java Build Path'。
• 明确Maven编译配置：在pom.xml的<build><plugins>中添加maven-compiler-plugin配置，强制指定编译和运行的JDK版本：

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.11.0</version>
    <configuration>
        <source>17</source>
        <target>17</target>
        <release>17</release>
    </configuration>
</plugin>

• 清理并重新构建项目：执行mvn clean install命令，清除旧编译产物，重新构建后再启动项目。

内容的提问来源于stack exchange，提问作者Megha Kumari