DB Provider

The db-provider module is a lightweight database provider designed to simplify the initialization of a generic SQL/JDBC data source, typically for internal services or control plane components (like light-portal or light-config-server) that need a single, primary database connection.

Overview

Unlike the more flexible data-source module which is designed for multiple, named data sources, db-provider focuses on providing a single, global HikariDataSource initialized at startup. It is often used in conjunction with a StartupHookProvider to ensure the database connection is ready before the server starts handling requests.

Configuration

The module is configured via db-provider.yml (or yaml/json).

Property	Description	Default
`driverClassName`	JDBC driver class name.	`org.postgresql.Driver`
`jdbcUrl`	JDBC connection URL.	`jdbc:postgresql://timescale:5432/configserver`
`username`	Database username.	`postgres`
`password`	Database password (supports encryption).	`secret`
`maximumPoolSize`	Max connections in the pool.	`3`

Example db-provider.yml:

driverClassName: org.h2.Driver
jdbcUrl: jdbc:h2:mem:testdb
username: sa
password: sa
maximumPoolSize: 5

Startup Hook

To use this module, you typically register the SqlDbStartupHook in your service.yml. This hook reads the configuration, creates the HikariDataSource, and initializes the CacheManager.

service.yml:

startupHooks:
  - com.networknt.db.provider.SqlDbStartupHook

Usage

Once initialized by the startup hook, the data source is available via the static field in SqlDbStartupHook.

import com.networknt.db.provider.SqlDbStartupHook;
import javax.sql.DataSource;
import java.sql.Connection;

public class MyService {
    public void doSomething() {
        DataSource ds = SqlDbStartupHook.ds;
        try (Connection conn = ds.getConnection()) {
            // ... perform DB operations
        } catch (SQLException e) {
            // handle exception
        }
    }
}

Key Classes

DbProviderConfig: Loads configuration from db-provider.yml.
SqlDbStartupHook: Initializes the global HikariDataSource and CacheManager.
DbProvider: Interface for provider extensions (defaulting to DbProviderImpl).

When to use

Use db-provider if you are building a simple service or a light-4j platform component (like Config Server) that needs a single, standard SQL connection setup globally at startup.
Use data-source if you need multiple data sources, named data sources, or more complex configuration that doesn’t rely on a specific startup hook.

Keyboard shortcuts