PostgreSQL Jsonb Entity Manager

Entity manager provides a simple way to persist and retrieve objects from postgres with a destructured schema. However it still has all the potential of SQL for querying.

Getting Started

The entity manager provides you of an easy way to persist and retrieve objects serialized to postgres jsonb structure:

SomeJsonbEntity entity = new SomeJsonbEntity("test");

entityManager.save(entity);
entityManager.findById(SomeJsonbEntity.class, entity.getId())
entityManager.findAll(SomeJsonbEntity.class);

This manager also separates the read queries from the write ones transparently, so you can scale your postgres with reading and writting nodes.

Prerequisites

It is necesary to have a PostgreSQL server with version over 9.4 and a database created. If you use the PostgresInitializer tool to create the databases, the user provided should have permissions to do that. Java version should be 8 or grather

The class will need to be marked with the TableName annotation that provides the tablename and the indexes needed for the initializer to create the structure:

@TableName(value = "test_table", indexes = { " -> 'indexedValue'" })
public class SomeJsonbEntity implements JsonbEntity {

	@JsonProperty
	private Long id;

	@JsonProperty
	private String indexedValue;

	@Override
	public Long getId() {
		return id;
	}

	@Override
	public void setId(Long id) {
		this.id = id;
	}

	public String getIndexedValue() {
		return indexedValue;
	}

	public void setIndexedValue(String indexedValue) {
		this.indexedValue = indexedValue;
	}

}
		

The initializer then will usage the table name info to work

PostgresConnector connector = new PostgresConnector(readDataSource, writingDataSource);
PostgresInitializer initializer = new PostgresInitializer(connector, tableNamesResolver);
initializer.initialize();
		

Installing

First add the dependency:

		<dependency>
			<groupId>com.etermax.jsonb.orm</groupId>
			<artifactId>jsonb-entity-manager</artifactId>
			<version>1.0-SNAPSHOT</version>
		</dependency>

or gradle

compile "com.etermax.jsonb.orm:jsonb-entity-manager:1.0-SNAPSHOT"

Then you will need to create the HikariDataSource (we choose this because it allows to reset connections and scale your reading nodes behind the balancer)

HikariDataSource hikariDataSource = HikariDataSourceBuilder.defaultDataSource()
    .withUrl(postgres.getJdbcUrl())
    .withPoolName("test")
    .withUser(postgres.getUsername())
    .withPassword(postgres.getPassword())
    .build();
		

The next step is to create the Postgres connector and the TableNameResolver (this las one recieves the package to scan the annotated classes)

PostgresConnector connector = new PostgresConnector(readHikariDataSource, writegHikariDataSource);

TableNamesResolver tableNamesResolver = new TableNamesResolver("com.your.jsonb.entities.package");

With all this you can prepare and create your entity mannager

JsonbEntityManager entityManager = new JsonbEntityManager(new ObjectMapper(), connector, tableNamesResolver);

Contributing

Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.

Authors

• Alejandra Juarez D'Aquino - Initial work - Jsonb Entity Manager

See also the list of contributors who participated in this project.

License

This project is licensed under the MIT License - see the LICENSE.md file for details