Retrieve .NET DLL array in GoLang app

This article shows how to retrieve array from called technology.

Javonet allows you to reference and use modules or packages written in (Java/Kotlin/Groovy/Clojure, C#/VB.NET, Ruby, Perl, Python, JavaScript/TypeScript) like they were created in your technology. If have not yet created your first project check Javonet overview and quick start guides for your technology.

Custom .NET DLL with array handling

With Javonet it is possible to reference any custom .NET DLL and interact with arrays declared on types defined within that module almost the same as with any other GoLang library.

Snippet below represents the sample code from .NET DLL that has methods which return or process the arrays:

namespace TestClass
{
	public class TestClass
	{
		public TestClass() { }

        public string[] Get1DArray()
        {
        	return new string[] { "one", "two", "three", "four", "five" };
        }
        
        public string[,] Get2DArray()
        {
        	return new string[,] { { "S00", "S01" }, { "S10", "S11" } };
        }
        
        public double AddArrayElementsAndMultiply(double[] myArray, double myValue)
        {
        	double sum = 0;
        	foreach (double element in myArray)
        	{
        		sum += element;
        	}
        
        	return sum * myValue;
        }
	}
}
public string[] Get1DArray()
{
	return new string[] { "one", "two", "three", "four", "five" };
}

public string[,] Get2DArray()
{
	return new string[,] { { "S00", "S01" }, { "S10", "S11" } };
}

public double AddArrayElementsAndMultiply(double[] myArray, double myValue)
{
	double sum = 0;
	foreach (double element in myArray)
	{
		sum += element;
	}

	return sum * myValue;
}

Retrieve .NET DLL array in GoLang application

With Javonet SDK it is possible to retrieve array from called technology and cast it to GoLang array.

package main

import (
	"fmt"
	Javonet "javonet.com/javonet"
)

var resourcesDirectory string = "."

func main() {
	_ = resourcesDirectory

  	// use Activate only once in your app
  	Javonet.ActivateWithCredentials("your-license-key")
  	
  	// create called runtime context
  	calledRuntime, _ := Javonet.InMemory().Netcore()
  	
  	libraryPath := resourcesDirectory + "/TestClass.dll"
  	className := "TestClass.TestClass"
  	
  	// load custom library
  	calledRuntime.LoadLibrary(libraryPath)
  	
  	// get type from the runtime
  	calledRuntimeType, _ := calledRuntime.GetType(className).Execute()
  	
  	// create type's instance
  	instance, _ := calledRuntimeType.CreateInstance().Execute()
  	
  	// invoke instance's method
  	arrayReference, _ := instance.InvokeInstanceMethod("Get1DArray").Execute()
  	
  	// get array from reference
  	response, _ := arrayReference.RetrieveArray()
  	
  	// create new array to copy response
  	result := make([]string, len(response))
  	for i, v := range response {
  		result[i] = v.(string)
  	}
  	
  	// write result to console
  	fmt.Println(result)
}
namespace TestClass
{
	public class TestClass
	{
		public TestClass() { }

        public string[] Get1DArray()
        {
        	return new string[] { "one", "two", "three", "four", "five" };
        }
        
        public string[,] Get2DArray()
        {
        	return new string[,] { { "S00", "S01" }, { "S10", "S11" } };
        }
        
        public double AddArrayElementsAndMultiply(double[] myArray, double myValue)
        {
        	double sum = 0;
        	foreach (double element in myArray)
        	{
        		sum += element;
        	}
        
        	return sum * myValue;
        }
	}
}
// use Activate only once in your app
Javonet.ActivateWithCredentials("your-license-key")

// create called runtime context
calledRuntime, _ := Javonet.InMemory().Netcore()

libraryPath := resourcesDirectory + "/TestClass.dll"
className := "TestClass.TestClass"

// load custom library
calledRuntime.LoadLibrary(libraryPath)

// get type from the runtime
calledRuntimeType, _ := calledRuntime.GetType(className).Execute()

// create type's instance
instance, _ := calledRuntimeType.CreateInstance().Execute()

// invoke instance's method
arrayReference, _ := instance.InvokeInstanceMethod("Get1DArray").Execute()

// get array from reference
response, _ := arrayReference.RetrieveArray()

// create new array to copy response
result := make([]string, len(response))
for i, v := range response {
	result[i] = v.(string)
}

// write result to console
fmt.Println(result)

In the snippet above, get1DArray method is used to get reference to 1D array from .NET DLL. Method retrieveArray is used to get the whole array from called technology and save it to local variable.

The same operation can be performed remotely by just changing the new Runtime Context invocation from in memory to tcp that will create and interact with your .NET DLL objects on any remote node, container or service that hosts Javonet Code Gateway. This way you can preserve the same logic in your application and instantly switch between monolithic and microservices architecture without the need to implement the integration layer based on web services or other remote invocation methods.

Read more about use cases and software architecture scenarios where Javonet runtime bridging technology can support your development process.

Retrieve .NET DLL array in GoLang app

Custom .NET DLL with array handling

Retrieve .NET DLL array in GoLang application

Additional references