Many developers face the challenge of integrating JDBC with languages that don’t natively support it, such as C#, JavaScript, Python, Go, and others. This creates a bottleneck for cross-platform applications where diverse technologies need to interact with Java-based databases. While native solutions and workarounds exist, they often come with significant complexity and limitations.
In this article, I’ll walk through a streamlined approach to enable JDBC access in non-Java languages, making it easier to connect cross-language applications to databases efficiently. We’ll explore both the technical hurdles involved and how they can be overcome.
The Traditional Approaches
Let’s quickly review some of the traditional methods developers use to tackle this issue:
- Writing Custom Bindings: Involves building a Java wrapper around the JDBC API and exposing it via a communication protocol (e.g., HTTP, REST). While this works, it introduces overhead and complexity.
- Using Middleware or Brokers: A separate middleware layer can be used to bridge communication, but it adds latency and increases potential points of failure.
- Language-Specific Solutions: Some languages have their own database drivers, but they rarely match the performance and feature set of JDBC, especially when working with Java-based systems.
A Simplified Approach Using Cross-Language Integration
To overcome these challenges, I explored a cross-language integration strategy that allows seamless JDBC access from C#, JavaScript, Python, Go, and others. By using this method, developers can bypass the need for middleware or custom bindings and directly connect their applications to databases via JDBC.
Here’s how it works:
- Language Interoperability: The solution enables direct calls from any supported language to the Java-based JDBC libraries, without writing Java code.
- Performance Optimization: Unlike HTTP-based approaches, this method minimizes latency by making direct method calls into the Java ecosystem.
- Simplicity and Consistency: It unifies the database access layer across multiple languages, meaning that developers can write consistent database code regardless of the programming language they’re using.
How It’s Implemented
Now let’s dive into the technical details. To achieve this, I utilized a framework that enables cross-language calls between Java and other programming languages, including .NET, Python, and JavaScript. Here’s an overview of the architecture:
- Interfacing with JDBC: The integration framework allows developers to load and invoke any Java class (including JDBC drivers) from non-Java code.
- Data Handling: Data passed between the languages maintains type safety, ensuring that database transactions are reliable and consistent.
- Error Handling: Exception handling from JDBC is propagated back to the calling language, meaning you can catch and handle exceptions natively, no matter what language you’re working in.
Alternative Solutions
There are a few well-known alternatives to Javonet for cross-language integration and JDBC access. Here’s a brief comparison:
- JNBridge:
Overview: JNBridge allows interoperability between Java and .NET, enabling calls from .NET to Java and vice versa.
Limitations: It’s mainly focused on bridging Java and .NET, which limits its flexibility in working with other languages like Python, JavaScript, or Go.
Use Case: Best suited for .NET and Java-specific integrations but requires more effort for multi-language environments. - GraalVM:
Overview: GraalVM is a high-performance runtime that supports running applications written in multiple languages (Java, JavaScript, Python, Ruby, etc.) with seamless interoperability.
Limitations: While it offers excellent cross-language capabilities, its setup is more complex, and performance can be an issue in certain scenarios. Additionally, it’s more tailored to executing polyglot applications, not necessarily for JDBC integration across different languages.
Use Case: Ideal for polyglot programming in single applications, but may be overkill for simple JDBC integration needs. - Apache Thrift:
Overview: Thrift is a framework for scalable cross-language services development. It supports a wide range of languages like C++, Java, Python, Go, and more.
Limitations: Thrift is focused on creating communication protocols between services and isn’t specifically optimized for direct database interaction or JDBC. It also requires building a whole infrastructure to manage services, which increases complexity.
Use Case: Best suited for cross-language microservices and RPC-based communication but over-complicated for basic JDBC integration.
In this article, we will explore how to leverage the best existing implementations of such components from other technologies using Javonet. Javonet is a commercial solution (offering Free Trial), that allows developers to reference libraries, classes, and public methods from different programming languages, facilitating seamless integration, like JDBC integration between various technologies.
Key Database Drivers Available in Java
Java provides a wide range of drivers that are well-optimized and feature-rich. Here are some key drivers available in Java that may be lacking or less efficient in Golang, Ruby, and C#:
- Oracle JDBC Driver – This driver is essential for applications using Oracle databases. While alternatives exist in Golang and Ruby, they often lack the full functionality of the official Oracle driver for Java.
- Microsoft SQL Server JDBC Driver – Java offers a highly efficient and comprehensive JDBC driver for SQL Server. Implementations in Golang and Ruby are less mature and may offer limited performance.
- IBM DB2 JDBC Driver – The JDBC driver for DB2 in Java is well-integrated and supported by IBM. Other programming languages have limited availability of well-optimized drivers for DB2.
- PostgreSQL JDBC Driver – Although PostgreSQL is well-supported in Golang and Ruby, the JDBC driver for Java offers exceptional support for advanced database features.
Challenges and Solutions: Using Javonet for Java JDBC Integration in Golang, Ruby, and C#
In this article, we will discuss how to leverage the best existing implementations of such components from any other technology using Javonet. This solution allows you to reference libraries, classes, and public methods, integrating solutions from different programming languages.
This method will allow us to achieve seamless integration between different technologies. For instance, we can directly access any JDBC driver (Hadoop, SQLite, etc.) from our code, regardless of whether we’re writing in C#, Go, Ruby, or any other technology supported by Javonet. This example demonstrates how to call JDBC Java methods for SQLite from a C# application. As a result, our C# class will receive data from the SQLite database.
If you still need to create your first project, check Javonet’s overview and quick start guides for your technology.
Preparing the Database
First, we need to prepare a sample database. In this example, we use an Order entity with some sample properties. Our Order table might look like this:
| Id | ProductId | Amount |
| 1 | 100 | 1000 |
| 2 | 200 | 1006 |
| 3 | 300 | 1007 |
Creating a Java Class
Next, we create a Java class to store data from the database. In this example, we will create a DBSample Java package:
package DBSample;
public class Order {
private int id;
private int productId;
private int amount;
public Order(int id, int productId, int amount) {
this.id = id;
this.productId = productId;
this.amount = amount;
}
public int getId() {
return id;
}
public int getProductId() {
return productId;
}
public int getAmount() {
return amount;
}
}
Storing Data in the Java Class
Now, let’s save some data in this class. In this example, we used sqlite-jdbc-3.31.1 version to avoid JDBC driver issues. We will use System.out.println() to confirm whether the method was invoked properly:
package DBSample;
import java.sql.DriverManager;import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class JavaDbConnector {
private static String ConnectionString = "";
public JavaDbConnector(String connectionString) {
ConnectionString = connectionString; }
public static Order getOrderById(int orderId) {
var sql = "SELECT * FROM Orders WHERE Id = ?";
List<Order> orders = new ArrayList<>();
try {
var connection = DriverManager.getConnection(ConnectionString);
var statement = connection.prepareStatement(sql);
statement.setInt(1, orderId);
var reader = statement.executeQuery();
while (reader.next()) {
int id = reader.getInt("Id");
int productId = reader.getInt("ProductId");
int amount = reader.getInt("Amount");
var order = new Order(id, productId, amount);
orders.add(order);
System.out.println(id + "\t\t" + productId + "\t\t" + amount);
}
return orders.get(0);
} catch (SQLException e) {
System.err.println(e.getMessage());
}
return null;
}
}
Exporting Java Code to a JAR File
Next, we export our Java code to a JAR file. This can be done in Eclipse by saving it as a runnable JAR and exporting all dependencies.
Creating a C# Application to Access Java JDBC
Once we have these elements ready, we can move on to the next step: creating the C# application. In this example, a simple console application will suffice. We need to create a class to store data on the C# side:
using Javonet.Netcore.Sdk;
public class Order{
private InvocationContext _context;
public int Id { get; } = (int)_context.InvokeInstanceMethod("getId").Execute().GetValue();
public int ProductId { get; } = (int)_context.InvokeInstanceMethod("getProductId").Execute().GetValue();
public int Amount { get; } = (int)_context.InvokeInstanceMethod("getAmount").Execute().GetValue();
public Order(InvocationContext context){
_context = context;
}
}
Activating Javonet and Creating InMemory Runtime for Cross-Language Integration
Javonet allows us to create an instance of another runtime in our application. For example, when writing in C# and running your application on CLR or .NET Core, you can use Javonet to request that it also run a JVM runtime, Python, or another runtime within the same process in inMemory mode. This approach provides us with the capability to interact with any other libraries, methods, or classes from this technology.
Now, let’s proceed to get data from SQLite via the JAR file from C#. We need to activate Javonet and create runtime:
Javonet.Activate("your_key_here");
var calledRuntime = Javonet.InMemory().Jvm();
Defining Variables and Loading the JAR File
Define the necessary variables:
string libraryPath = "<path_to_your_JAR_file>"; string className = "DBSample.JavaDbConnector"; string connectionString = "jdbc:sqlite:<path_to_your_SQLite_file>";
Load the JAR file:
calledRuntime.LoadLibrary(libraryPath);
Creating an Instance and Invoking Methods
Get the type and create an instance of this type:
InvocationContext calledRuntimeType = calledRuntime.GetType(className).Execute(); InvocationContext instance = calledRuntimeType.CreateInstance(connectionString).Execute();
Invoke a Java method to get an order by its ID:
InvocationContext response = instance.InvokeInstanceMethod("getOrderById", 1).Execute();
Now we can create an instance of the C# Order class:
Order orderInstance = new Order(instance);
Console.WriteLine($"ID: {orderInstance.Id} | Product ID: {orderInstance.ProductId} | Amount: {orderInstance.Amount}");
How to Retrieve and Manipulate Data from Java to C# Using JDBC Integration
When working with databases, a common task is retrieving a list of entities. In this tutorial, we’ll explore how to achieve this in Java and then wrap the functionality in C# to make it possible to use JDBC drivers directly from .NET.
Creating a Java Method to Retrieve Orders
To start, you’ll need to create a new method in your JavaDbConnector class. This method will retrieve a list of Order entities from your database.
public static List<Order> getOrders() {
var sql = "SELECT * FROM Orders";
List<Order> orders = new ArrayList<Order>();
try {
var connection = DriverManager.getConnection(ConnectionString);
var statement = connection.prepareStatement(sql);
var reader = statement.executeQuery();
while (reader.next()) {
int id = reader.getInt("Id");
int productId = reader.getInt("ProductId");
int amount = reader.getInt("Amount");
var order = new Order(id, productId, amount);
orders.add(order);
System.out.println(id + "\t\t" + productId + "\t\t" + amount);
}
return orders;
} catch (SQLException e) {
System.err.println(e.getMessage());
}
return null;
}
Wrapping the Java Method in C#
Now that we have our Java method, we can create a C# class to interact with it. The first task is to replicate Java method interface which forward calls to extract data from the Java side. Start by implementing a simple OrderListExtractor class:
public class OrderListExtractor
{
private InvocationContext _context;
public OrderListExtractor(InvocationContext context)
{
_context = context;
}
public int Size()
{
return (int)_context.InvokeInstanceMethod("size").Execute().GetValue();
}
public Order Get(int index)
{
var orderContext = _context.InvokeInstanceMethod("get", index).Execute();
return new Order(orderContext);
}
public List<Order> GetOrders()
{
var size = Size();
var result = new List<Order>();
for (int i = 0; i < size; i++)
{
Order order = Get(i);
result.Add(order);
}
return result;
}
}
Invoking the Java Method and Manipulating Data in C#
With your OrderListExtractor class ready, you can now invoke the Java method from C# and manipulate the retrieved data:
InvocationContext responseList = instance.InvokeInstanceMethod("getOrders").Execute();
List<Order> orders = new OrderListExtractor(responseList).GetOrders();
for (int i = 0; i < orders.Count; i++)
{
Order order = orders[i];
Console.WriteLine($"ID: {order.Id} | Product ID: {order.ProductId} | Amount: {order.Amount}");
}
Direct JDBC Invocation from C#
Alternatively, you can bypass the Java application layer and directly perform JDBC Integration and call Java framework methods from C#. Here's how you can do it:
Javonet.Activate("your-license-key");
var calledRuntime = Javonet.InMemory().Jvm();
string libraryPath = "<path to your JDBC SQLite JAR file>";
string className = "java.sql.DriverManager";
string connectionString = "jdbc:sqlite:<path to your SQLite file>";
string sql = "SELECT * FROM Orders WHERE Id = ?";
var calledRuntimeType = calledRuntime.GetType("java.sql.DriverManager").Execute();
var command = connection.InvokeInstanceMethod("prepareStatement", sql).Execute();
command.InvokeInstanceMethod("setInt", 1, 1).Execute();
var reader = command.InvokeInstanceMethod("executeQuery").Execute();
var id = (int)reader.InvokeInstanceMethod("getInt", "Id").Execute().GetValue();
Benefits of Using Javonet for JDBC Integration in Golang, Ruby, and C#
By using Javonet, developers can leverage the extensive ecosystem of Java's JDBC drivers, enabling robust and feature-rich database interactions within Golang, Ruby, and C# applications. This integration:
• Enhances Functionality: Access advanced features of databases that are otherwise limited or unavailable in Golang and Ruby.
• Improves Performance: Utilize the highly optimized and efficient JDBC drivers to ensure better performance and reliability.
• Increases Flexibility: Seamlessly integrate and interact with multiple database systems from different programming environments.
• Reduces Development Time: Simplify the integration process and reduce the time needed to develop cross-platform solutions.
Conclusion
Using Javonet, we successfully integrated a Java JDBC library to retrieve data from an SQLite database in a C# application. This example highlights the potential benefits of Javonet, showcasing the numerous possibilities and combinations it offers for solving various challenges. By accessing Java's robust ecosystem of database drivers, developers working with Golang, Ruby, or C# can significantly enhance their applications' functionality and performance.
We'd love to hear your take on this. Share with us how you could use this approach and what challenges you believe it could help you overcome!