JPA/Hibernate ORM abstraction layer with L2 caching (EhCache), custom Gson-backed Hibernate type converters, and a repository pattern implementation. Provides read-only cached repositories, session management, per-entity TTL annotations, and support for multiple database drivers.

• Features
• Getting Started
  • Prerequisites
  • Installation
• Usage
• Supported Drivers
• Architecture
  • Package Overview
  • Project Structure
• Dependencies
• Contributing
• License

• Repository pattern - Read-only cached Repository interface with JpaRepository implementation for CRUD operations, cache eviction, and stream-based querying
• Session management - SessionManager registry for multiple concurrent JpaSession instances with cross-session repository lookup, reconnection, and coordinated shutdown
• L2 caching - EhCache-backed second-level cache with per-entity TTL via @CacheExpiry annotation and configurable cache concurrency strategies
• Custom Hibernate types - Gson-backed type converters for JSON columns (GsonJsonType, GsonListType, GsonMapType, GsonOptionalType)
• Multiple database drivers - MariaDB, H2 (file, memory, TCP), Oracle Thin, PostgreSQL, SQL Server
• Type converters - Built-in JPA attribute converters for Color, UUID, and Unicode strings
• JSON persistence sources - Source interface with JsonSource implementation for file-based data loading
• Repository factory - RepositoryFactory with topological entity sorting, per-type source registration, and classpath-based model discovery
• Foreign ID resolution - @ForeignIds transient field population for cross-entity relationships loaded from non-relational sources
• Stale entity cleanup - Automatic removal of database rows not present in the latest source load, in FK-safe reverse topological order

Published via JitPack. Add the JitPack repository and dependency to your build file.

repositories {
    mavenCentral()
    maven(url = "https://jitpack.io")
}

dependencies {
    implementation("com.github.simplified-dev:persistence:master-SNAPSHOT")
}

repositories {
    mavenCentral()
    maven { url 'https://jitpack.io' }
}

dependencies {
    implementation 'com.github.simplified-dev:persistence:master-SNAPSHOT'
}

Define a JPA entity model:

import dev.simplified.persistence.CacheExpiry;
import dev.simplified.persistence.JpaModel;
import jakarta.persistence.*;

import java.util.concurrent.TimeUnit;

@Entity
@CacheExpiry(duration = 5, unit = TimeUnit.MINUTES)
public class User extends JpaModel {

    @Id
    private Long id;
    private String name;
}

Configure and connect a session:

import dev.simplified.persistence.JpaConfig;
import dev.simplified.persistence.SessionManager;
import dev.simplified.persistence.driver.MariaDbDriver;

JpaConfig config = JpaConfig.common(new MariaDbDriver(), "mydb")
    .withHost("localhost")
    .withPort(3306)
    .withUser("root")
    .withPassword("secret")
    .build();

SessionManager sessionManager = new SessionManager();
sessionManager.connect(config);

Query cached data through the repository:

import dev.simplified.persistence.Repository;

Repository<User> userRepo = sessionManager.getRepository(User.class);
ConcurrentList<User> users = userRepo.findAll();

persistence/
├── src/
│   ├── main/java/dev/simplified/persistence/
│   │   ├── CacheExpiry.java
│   │   ├── CacheMissingStrategy.java
│   │   ├── ForeignIds.java
│   │   ├── JpaConfig.java
│   │   ├── JpaExclusionStrategy.java
│   │   ├── JpaModel.java
│   │   ├── JpaRepository.java
│   │   ├── JpaSession.java
│   │   ├── Repository.java
│   │   ├── RepositoryFactory.java
│   │   ├── SessionManager.java
│   │   ├── converter/
│   │   │   ├── ColorConverter.java
│   │   │   ├── UUIDConverter.java
│   │   │   └── UnicodeConverter.java
│   │   ├── driver/
│   │   │   ├── H2FileDriver.java
│   │   │   ├── H2MemoryDriver.java
│   │   │   ├── H2TcpDriver.java
│   │   │   ├── JpaDriver.java
│   │   │   ├── MariaDbDriver.java
│   │   │   ├── OracleThinDriver.java
│   │   │   ├── PostgreSqlDriver.java
│   │   │   └── SqlServerDriver.java
│   │   ├── exception/
│   │   │   └── JpaException.java
│   │   ├── source/
│   │   │   ├── JsonSource.java
│   │   │   └── Source.java
│   │   └── type/
│   │       ├── ConverterRegistrar.java
│   │       ├── GsonJsonType.java
│   │       ├── GsonListType.java
│   │       ├── GsonMapType.java
│   │       ├── GsonOptionalType.java
│   │       ├── GsonType.java
│   │       └── TypeRegistrar.java
│   └── test/
├── build.gradle.kts
├── gradle/
│   └── libs.versions.toml
└── LICENSE.md

See CONTRIBUTING.md for development setup, code style guidelines, and how to submit a pull request.

This project is licensed under the Apache License 2.0 - see LICENSE.md for the full text.