Get/Set Values for Instance Fields and Properties

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To set or get values of instance fields and properties, get or create an instance of the object from JAR library, and call "get(fieldOrPropertyName)" or "set(fieldOrPropertyName,newValue)" methods on NObject\JObject containing this field. Assuming we have a custom JAR library with the following class inside:

public class TestClass {
    public TestClass() {

    public static int MyStaticField;

    public int MyInstanceField;

    public static String SayHello(String name) {
        return "Hello " + name;

    public static int MethodExpectingPrimitiveInt(int arg) {
        return arg * 2;

    public static int MethodExpectingClassInteger(Integer arg) {
        return arg * 2;

    public int MultiplyByTwo(Integer arg) {
        return arg * 2;

    public <T> T MyGenericMethod(T arg1)
        return arg1;

To set and get instance field from this class:

I code in:
// Todo: activate Javonet

// add reference to library
Javonet.AddReference(resourcesDirectory + @"\TestClass.jar");

// create Java object
JObject sampleObject = Javonet.New("TestClass");

// set instance field
sampleObject.Set("MyInstanceField", 11);

// get instance field
int response = sampleObject.Get<int>("MyInstanceField");

// write result to console

See Live Example!