How to configure Spring Boot with common Entity class and multiple projects

Question

i have multiple project with common entity classes. So i created jar file of that common entity class and added this jar as library for multiple projects (right click on project -> property->libraries->Add external jars).

common entity folder under package com.company.apmg.entity;

And the multiple project have the folder structure like

`com.company.apmg.usermanagement.v1`;
`com.company.apmg.shippingmanagement.v1`;
`com.company.apmg.billingmanagement.v1`;

here have the controller,service and repository files.

On compiling projects no issues found.

But running application it shows Entity class is Not a managed type. How i can solve this issue...

I referred the google but no one could not solve my issue.

Answer 1

It is that you are creating different persistence units, which in turn creates different entity managers. So, try to scan the entity classes inside your project. For instance, you can add a class PersistenceConfig like below.

@Configuration
@EnableJpaRepositories(basePackages = { "your.package.repositories" })
public class PersistenceConfig {
    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
        LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
        em.setDataSource(dataSource());
        em.setPackagesToScan("your.package.entities");

        JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        em.setJpaVendorAdapter(vendorAdapter);
        em.setJpaProperties(additionalProperties());

        return em;
    }
@Bean
public DataSource dataSource() {
    DriverManagerDataSource dataSource = new DriverManagerDataSource();
    dataSource.setDriverClassName("com.mysql.jdbc.Driver"); //com.mysql..cj.* is added on version 8 of the driver
    dataSource.setUrl("jdbc:mysql://localhost:3306/db");
    dataSource.setUsername("root");
    dataSource.setPassword("root");
    return dataSource;
}

@Bean
public PlatformTransactionManager transactionManager(EntityManagerFactory emf) {
    JpaTransactionManager transactionManager = new JpaTransactionManager();
    transactionManager.setEntityManagerFactory(emf);

    return transactionManager;
}

@Bean
public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {
    return new PersistenceExceptionTranslationPostProcessor();
}

Properties additionalProperties() {
    Properties properties = new Properties();
    properties.setProperty("hibernate.hbm2ddl.auto", "update");
    properties.setProperty("hibernate.dialect", "org.hibernate.dialect.MySQL5Dialect");

    return properties;
}
}