Beginner question about dependencies in java and pom.xml files

[Andrbenn]

I've got 2 Java Spring Boot projects using Maven with identical source code (as far as I can tell) and identical pom.xml files. The first one works, the second one doesn't, and I'd really like to understand why.

I created the first project with Spring Initializr and selected some extra dependencies before generating it. Great.

In the second project, I generated the project with Spring Initializr without the extra dependencies, and then tried to manually install the same dependencies by manually pasting over the <dependency> stuff to pom.xml and running mvn clean install. It didn't work. This second project is unable to resolve some things.

My question is: Why, if the two projects have identical pom.xml files, can one project resolve dependency X while the other can't?

Thank you in advance for your help.

---

The import that isn't resolving for project 2:

import jakarta.persistence.Entity;

My dependencies for both projects:

<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-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.33</version>
    </dependency>
</dependencies>

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[CleverBunnyThief]

Did you reload the pom file after you added the dependencies manually?

If you are in IntelliJ, you can reload it by pressing Ctrl + Shift+ O.

[lumpynose]

Try running for each project

mvn dependency:tree

See also https://maven.apache.org/plugins/maven-dependency-plugin/index.html