[FIXED] @SpringBootApplication Not found error coming on module

Issue

I am creating microservice application. for which we have a pom in the project. Under this we have multiple modules. I am using Java11 and spring 2.5.4.

below is my pom. from this all the modules will get versions. Its packaging is 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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <modules>
        <module>twitter-to-kafka-service</module>
    </modules>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.4</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.microservices.demo</groupId>
    <artifactId>microservices-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>microservices-demo</name>
    <description>Microservices demo project for Spring Boot</description>
    <packaging>pom</packaging>

    <properties>
        <java.version>11</java.version>
        <spring-boot.version>2.5.4</spring-boot.version>
        <maven-compiler-plugin.version>3.8.1</maven-compiler-plugin.version>
        <twitter4j.version>4.0.7</twitter4j.version>
        <lombok.version>1.18.16</lombok.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter</artifactId>
                <version>${spring-boot.version}</version>
            </dependency>

            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <version>${spring-boot.version}</version>
                <scope>test</scope>
                <exclusions>
                    <exclusion>
                        <groupId>org.junit.vintage</groupId>
                        <artifactId>junit-vintage-engine</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>

            <!-- https://mvnrepository.com/artifact/org.twitter4j/twitter4j-stream -->
            <dependency>
                <groupId>org.twitter4j</groupId>
                <artifactId>twitter4j-stream</artifactId>
                <version>${twitter4j.version}</version>
            </dependency>

            <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>${lombok.version}</version>
                <scope>provided</scope>  <!-- only for compile time-->
            </dependency>


        </dependencies>

    </dependencyManagement>



    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>${maven-compiler-plugin.version}</version>
                <configuration>
                    <release>11</release>
                </configuration>
            </plugin>
        </plugins>
        <pluginManagement>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                    <version>${spring-boot.version}</version>
                </plugin>
            </plugins>
        </pluginManagement>

    </build>

</project>

Under this project I created one module for which pom is the below.

<?xml version="1.0" encoding="UTF-8"?>
<!--suppress MavenModelInspection, MavenModelInspection -->
<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">
    <parent>
        <artifactId>microservices-demo</artifactId>
        <groupId>com.microservices.demo</groupId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>twitter-to-kafka-service</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.twitter4j</groupId>
            <artifactId>twitter4j-stream</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <scope>provided</scope>  <!-- only for compile time-->
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <properties>
        <maven.compiler.source>15</maven.compiler.source>
        <maven.compiler.target>15</maven.compiler.target>
    </properties>

</project>

Now I am creating main class from where our application will begin. so When i am doing @SpringBootApplication it is saying not found. I am really not sure what I am missing.

I need your help to resolve the same as i am just starting it and got stuck. Please help me on the same.

Solution

You are using IntelliJ IDEA and did not update the pom information (Icon in the uppoer right with small 'm' symbol.)

Therefore the dependencies are not resolved properly.

Besides I suggest to use a single module project for spring boot applications, if there is no real requirement to do otherwise.

Answered By - Thomas
Answer Checked By - Mary Flores (JavaFixing Volunteer)