IntelliJ Spring Boot cannot find or load main class

Question

When I try to run the app, I get:

Error: Could not find or load main class com.example.springboot.JgsbrmqApplication
Caused by: java.lang.ClassNotFoundException: com.example.springboot.JgsbrmqApplication

Main Class:

package com.example.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class JgsbrmqApplication {

    public static void main(String[] args) {
        SpringApplication.run(JgsbrmqApplication.class, args);
    }

}

I have tried everything: reloading the project, mvn clean install (which gives an error, something to do with Java 17):

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.11.0:compile (default-compile) on project jgsbrmq: Fatal error compiling: error: release version 17 not supporte
d -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

Here is my pom.xml.

<?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>3.2.0</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>jgsbrmq</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>jgsbrmq</name>
    <description>Demo project for Spring Boot and RabbitMQ</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-amqp</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </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>org.springframework.amqp</groupId>
            <artifactId>spring-rabbit-test</artifactId>
            <scope>test</scope>
        </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>
            <!--<plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.11.0</version>
            </plugin>-->
        </plugins>
    </build>

</project>

Answer 1

I had same error.

This fixed for me. Intellij 2023.2.5 invalidate cache as follow:

File -> Invalidate Caches... -> check only first -> Invalidate and Restart