JPA-Maven Setup in IntelliJ

Technologies

• Maven
• Java 17
• JPA
• Hibernate
• PostgresSQL

How-to

1. Open IntelliJ and create a new project.
2. Select Maven and Java 17 or higher.
3. In advanced settings, add groupId.

4. Click finish.

   

5. Open the pom.xml file and add the following dependencies:

    <dependencies>
           
        <!--  DB    -->
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>${postgres.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate.orm</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>${hibernate-version}</version>
        </dependency>
           
        <!--  LOMBOK    -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${lombok.version}</version>
            <scope>provided</scope>
        </dependency>
           
        <!--  TESTING      -->
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-params</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
   

6. Add the following lines into the properties tag

    <lombok.version>1.18.36</lombok.version>
    <hibernate-version>6.6.6.Final</hibernate-version>
    <junit.version>5.11.4</junit.version>
    <postgres.version>42.7.5</postgres.version>
   

7. Create a new java class file called HibernateConfig (1).

   

8. Copy and paste the following Link into the HibernateConfig.class

9. The HibernateConfig.class uses a few methods and classes that are not yet created. You will need to create these classes and methods yourself. Check illustration above to see reference and project structure - and grab the code below:

   (2) Add the package exceptions and add this custom exception class:

    package app.exceptions;
   
    public class ApiException extends RuntimeException {
        private int code;
   
        public ApiException(int code, String msg){
            super(msg);
            this.code = code;
        }
        public int getCode(){
            return code;
        }
    }
   

   (3) Add the package util and add this class:

    package app.utils;
   
    import app.exceptions.ApiException;
   
    import java.io.IOException;
    import java.io.InputStream;
    import java.util.Properties;
   
    public class Utils {
   
        public static String getPropertyValue(String propName, String resourceName)  {
            try (InputStream is = Utils.class.getClassLoader().getResourceAsStream(resourceName)) {
                Properties prop = new Properties();
                prop.load(is);
   
                String value = prop.getProperty(propName);
                if (value != null) {
                    return value.trim();  // Trim whitespace
                } else {
                    throw new ApiException(500, String.format("Property %s not found in %s", propName, resourceName));
                }
            } catch (IOException ex) {
                throw new ApiException(500, String.format("Could not read property %s.", propName));
            }
        }
    }
   

   (4) In the resource folder, add a configuration called: `config.properties’:

    DB_NAME=name_of_your_db
    DB_USERNAME=postgres
    DB_PASSWORD=postgres
   

10. Add a proper .gitignore file:

    • https://gist.github.com/jonbertelsen/48bfceee0efa71eacc2c87773aa0d4d7