JPA setup in IntelliJ

• Maven
• Java 17
• JPA
• Hibernate (implementation of JPA)
• PostgresSQL

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>1.18.38</lombok.version>
       <hibernate-version>7.1.0.Final</hibernate-version>
       <junit.version>5.13.4</junit.version>
       <postgres.version>42.7.7</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