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AndroidJavaClass and AndroidJavaObject for C# .Net Framework

I have code in Unity that calls a function programmed in Java for Android using AndroidJavaClass and AndroidJavaObject and I would like to pass this code to a dll in C# .Net but I can't find an easy way to call Java functions using C# .Net since the AndroidJavaObject and AndroidJavaClass classes are exclusive to the Unity dll, here is an example of my code:
Java (Android):
public class DeviceManager {
public interface DeviceListener {
void DoSomething();
}
private DeviceListener deviceListener;
public DeviceManager(DeviceListener deviceListener){
this.deviceListener = deviceListener;
}
public String[] getSomeData(){
return new String[]{};
}
}
C# (Unity):
public class DeviceListener : AndroidJavaProxy
{
DeviceManager deviceManager;
public DeviceListener(DeviceManager manager) : base("com.myapp.DeviceManager$DeviceListener")
{
this.deviceManager = manager;
}
public void DoSomething();
}
public class DeviceManager
{
private AndroidJavaObject jo;
public DeviceManager(){
jo = new AndroidJavaObject("com.myapp.DeviceManager", new DeviceListener(this));
}
public string[] GetData(){
AndroidJavaObject returnedData = jo.Call<AndroidJavaObject>("getSomeData");
return AndroidJNIHelper.ConvertFromJNIArray<string[]>(returnedData.GetRawObject());
}
}
What is the best way to do that example in C# .Net instead of Unity?
EDIT: my main question is related to know how to get objects and call functions from an .aar file in .NET Framework inside a dll C# file for Unity
EDIT 2: I found some information about Xamarin, maybe that is what I am looking for?: https://github.com/xamarin/monodroid-samples/tree/master/JavaIntegration/AarBinding But even though I could link an .aar file to a dll in C# that doesn't quite answer my question in the best way to create a code that works the same as the example described above
EDIT 3: Currently, to solve this problem, I am using the UnityEngine .dll in my Visual Studio project but I want to generate a .dll for use in other graphics engines so I would like to be able to find a different solution than using Unity's own .dll for solve this problem, hence I mentioned Xamarin since it is a good way to communicate .Net Framework with Android (Java) but I have not found any example that uses it outside of a mobile application created in Visual Studio since in my case I would need to obtain objects and call functions from the .aar file

It seems like you are looking to use an AAR plugin, I haven't done it myself, but Unity has a doc on how to integrate it in your project.
Then, once that library is compiled in Android studio and integrated in Unity, you can look at this example on how to call it from C# code.
I haven't done it myself, but the example should put you on the right track.
Regarding the scripting backend, I don't believe it will have any impact on this.
Edit
Added Extract from the Example
Assets / Plugins / Android
Place your native android .AAR file inside this folder.
Now let’s write some code to call the plugin.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class NativeCodeRunner : MonoBehaviour
{
void Start(){
CallNativePlugin();
}
//method that calls our native plugin.
public void CallNativePlugin()
{
// Retrieve the UnityPlayer class.
AndroidJavaClass unityPlayerClass = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
// Retrieve the UnityPlayerActivity object ( a.k.a. the current context )
AndroidJavaObject unityActivity = unityPlayerClass.GetStatic<AndroidJavaObject>("currentActivity");
// Retrieve the "Bridge" from our native plugin.
// ! Notice we define the complete package name.
AndroidJavaObject alert = new AndroidJavaObject("plugins.vsoft.com.library.Alert");
// Setup the parameters we want to send to our native plugin.
object[] parameters = new object[2];
parameters[0] = unityActivity;
parameters[1] = "Hello World!";
// Call PrintString in bridge, with our parameters.
alert.Call("PrintString", parameters);
}
}

my main question is related to know how to get objects and call
functions from an .aar file in .NET Framework inside a dll C# file for
Unity
If you want to use AndroidJavaClass or AndroidJavaObject methods in your custom DLL, you should add references to the Unity DLLs. In Visual Studio, open the contextual menu for References in the Solution Explorer and select Add Reference. Then, select Browse > Select File.
At this stage, select the required .dll file, located in the UnityEngine folder.
using System;
/* Unity */
using UnityEngine;
namespace DLLTest {
public class MyDLLTest {
}
}

Possible to only load specific lines of code according to Android OS version?

Is there a simple line of code that would allow only loading the code if the OS version meets the requirements?
Lets say I have my target OS as 2.2 but the min sdk is 3 for android 1.5 so even if i have some code in my project that isn't compatable with 1.5 it will still compile since the target OS is 2.2. Anyway, I want to ad a feature that requires code that's not in the 1.5 SDK and will cause a crash if it's loaded on a 1.5 phone. Is there a simple thing like this that I can do? So i dont have to make the entire app not available to 1.5 users?
if (Android OS == >2.1){
//Insert code here that requires 2.1 and up}
else{
//insert code that would appear is OS is <2.1}

Yes, you can do that. In fact there is more than one way. (Note: the only Android specific part of this answer is the way that you find out the platform version.)
Suppose that class X has method void y() in version 2.0 onwards, but not before.
One way to invoke this method with out introducing any compile time dependencies whatsoever is to use reflection to locate the Method and call invoke on it. For example:
X x = ...
if (BUILD.VERSION.RELEASE.compareTo("2.0") >= 0) {
// (exception handling omitted ...)
Method m = c.getClass().getDeclaredMethod("y");
m.invoke(x);
}
Another way is to create a version compatibility adapter API for your application like this:
/** Version compatibility adapter API */
interface Compat {
void doY();
}
/** Adapter class for version 1 */
class CompatV1 {
public void y(X x) {
// do nothing
}
}
/** Adapter class for version 2 */
class CompatV2 {
public void y(X x) {
x.y();
}
}
//
// Code to instantiate the relevant adapter for the current platform.
//
Class<?> compatClass;
// (Exception handling omitted)
if (BUILD.VERSION.RELEASE.compareTo("2.0") < 0) {
compatClass = Class.forName("...CompatV1");
} else {
compatClass = Class.forName("...CompatV2");
}
// (Exception handling omitted)
Compat compat = (Compat) compatClass.newInstance();
// The adapter object can be passed around as a parameter, wrapped
// as a singleton or injected using dependency injection.
// Invoke X.y() as follows:
X x = ...
compat.y(x);
The second version looks a bit heavyweight, but it has the advantages that the dynamic (slow, non-type-safe) code is executed just once, and that the version specific code is isolated from the rest of the code. In real life, you would probably put a number of methods into the adapter interface.
This approach requires a bit more thought, to work out how to design the compatibility API so that it cleanly isolates the version dependencies from the rest of the code. You might also to have to revise the adapter API, and create new adapter classes for each new (incompatible) major release.
Finally, if the platform API changes that you need to adapt to entail using classes or methods in the older version that are removed in the newer version, then you will need to compile your various adapter classes (e.g. the CompatV* classes) using different Android SDKs. This will make your build processes rather more complicated.
For other "takes" on this problem, read the following articles on the Android Blog:
Backward compatibility for Android applications
How to have your (Cup-)cake and eat it too.

Here is another example w/o reflection
http://android-developers.blogspot.com/2010/07/how-to-have-your-cupcake-and-eat-it-too.html

See Backward compatibility for Android (using Reflection).

You can check with Build.VERSION.RELEASE, it gives you the current version of your android system (1.5,1.6,2.1,2.2)
There is more on Build.VERSION

Problem loading R own created libraries in Java/JRI code

I created my own new R library (called "Media"). There is no problem when I try to load it with RGui, and I can call the functions defined in the new package. This is how I load it:
> library(Media)
But, I'm also trying to call that functions from Java/JRI code, and when I load the new R package, Java doesn't seem to find the pacakge, throwing the message "Error in library(Media) : object 'Media' not found"
This is my current code using JRI:
REXP rexpSetFolder = re.eval("setwd('C:/Users/Albert/Documents')");
REXP rexpFolder = re.eval("getwd()");
System.out.println(rexpFolder.asString());
REXP rexpLoad = re.eval("library(Media)"); // fails
It also fails without the 'setwd' command, and simple calls to existing R functions work fine. I'm using R 2.10 and the latest JRI 0.5-0 under Windows.
Any help would be appreciated.
Thank you very much.
Edit:
The parameter lib.loc seems to work, at least this sentence does not return an error:
library("Media", lib.loc = "c:/Users/Albert/Documents")
But after that, calling a function in the package with re.eval("myfunction()"); still fails, as the function is not properly found.

You can modify the library path - see ?.libPaths in R, you simply want to add your private library to the path. The GUI does that for you, but if you are outside it doesn't happen. For example:
re.eval(".libPaths('c:/users/foo/Documents/R')");
Then load your package.

Did you install the library properly first? You might want to try using the lib.loc parameter.
library("Media", lib.loc = "c:/Users/Albert/Documents")

My work-around was to copy the package from my personal library (%USERPROFILE%\Documents\R) to the global library (%R_HOME%\library).
It's not the best because this requires Administrator privileges which not all users will have...

Pinning a Java application to the Windows 7 taskbar

I use Launch4j as a wrapper for my Java application under Windows 7, which, to my understanding, in essence forks an instance of javaw.exe that in turn interprets the Java code. As a result, when attempting to pin my application to the task bar, Windows instead pins javaw.exe. Without the required command line, my application will then not run.
As you can see, Windows also does not realize that Java is the host application: the application itself is described as "Java(TM) Platform SE binary".
I have tried altering the registry key HKEY_CLASSES_ROOT\Applications\javaw.exe to add the value IsHostApp. This alters the behavior by disabling pinning of my application altogether; clearly not what I want.
After reading about how Windows interprets instances of a single application (and a phenomenon discussed in this question), I became interested in embedding a Application User Model ID (AppUserModelID) into my Java application.
I believe that I can resolve this by passing a unique AppUserModelID to Windows. There is a shell32 method for this, SetCurrentProcessExplicitAppUserModelID. Following Gregory Pakosz suggestion, I implemented it in an attempt to have my application recognized as a separate instance of javaw.exe:
NativeLibrary lib;
try {
lib = NativeLibrary.getInstance("shell32");
} catch (Error e) {
Logger.out.error("Could not load Shell32 library.");
return;
}
Object[] args = { "Vendor.MyJavaApplication" };
String functionName = "SetCurrentProcessExplicitAppUserModelID";
try {
Function function = lib.getFunction(functionName);
int ret = function.invokeInt(args);
if (ret != 0) {
Logger.out.error(function.getName() + " returned error code "
+ ret + ".");
}
} catch (UnsatisfiedLinkError e) {
Logger.out.error(functionName + " was not found in "
+ lib.getFile().getName() + ".");
// Function not supported
}
This appears to have no effect, but the function returns without error. Diagnosing why is something of a mystery to me. Any suggestions?
Working implementation
The final implementation that worked is the answer to my follow-up question concerning how to pass the AppID using JNA.
I had awarded the bounty to Gregory Pakosz' brilliant answer for JNI that set me on the right track.
For reference, I believe using this technique opens the possibility of using any of the APIs discussed in this article in a Java application.

I don't have Windows 7 but here is something that might get you started:
On the Java side:
package com.stackoverflow.homework;
public class MyApplication
{
static native boolean setAppUserModelID();
static
{
System.loadLibrary("MyApplicationJNI");
setAppUserModelID();
}
}
And on the native side, in the source code of the `MyApplicationJNI.dll library:
JNIEXPORT jboolean JNICALL Java_com_stackoverflow_homework_MyApplication_setAppUserModelID(JNIEnv* env)
{
LPCWSTR id = L"com.stackoverflow.homework.MyApplication";
HRESULT hr = SetCurrentProcessExplicitAppUserModelID(id);
return hr == S_OK;
}
Your question explicitly asked for a JNI solution. However, since your application doesn't need any other native method, jna is another solution which will save you from writing native code just for the sake of forwarding to the windows api. If you decide to go jna, pay attention to the fact that SetCurrentProcessExplicitAppUserModelID() is expecting a UTF-16 string.
When it works in your sandbox, the next step is to add operating system detection in your application as SetCurrentProcessExplicitAppUserModelID() is obviously only available in Windows 7:
you may do that from the Java side by checking that System.getProperty("os.name"); returns "Windows 7".
if you build from the little JNI snippet I gave, you can enhance it by dynamically loading the shell32.dll library using LoadLibrary then getting back the SetCurrentProcessExplicitAppUserModelID function pointer using GetProcAddress. If GetProcAddress returns NULL, it means the symbol is not present in shell32 hence it's not Windows 7.
EDIT: JNA Solution.
References:
The JNI book for more JNI examples
Java Native Access (JNA)

There is a Java library providing the new Windows 7 features for Java. It's called J7Goodies by Strix Code. Applications using it can be properly pinned to the Windows 7 taskbar. You can also create your own jump lists, etc.

I have implemented access to the SetCurrentProcessExplicitAppUserModelID method using JNA and it works quite well when used as the MSDN documentation suggests. I've never used the JNA api in the way you have in your code snippet. My implementation follows the typical JNA usage instead.
First the Shell32 interface definition:
interface Shell32 extends StdCallLibrary {
int SetCurrentProcessExplicitAppUserModelID( WString appID );
}
Then using JNA to load Shell32 and call the function:
final Map<String, Object> WIN32API_OPTIONS = new HashMap<String, Object>() {
{
put(Library.OPTION_FUNCTION_MAPPER, W32APIFunctionMapper.UNICODE);
put(Library.OPTION_TYPE_MAPPER, W32APITypeMapper.UNICODE);
}
};
Shell32 shell32 = (Shell32) Native.loadLibrary("shell32", Shell32.class,
WIN32API_OPTIONS);
WString wAppId = new WString( "Vendor.MyJavaApplication" );
shell32.SetCurrentProcessExplicitAppUserModelID( wAppId );
Many of the API's in the last article you mentioned make use of Windows COM which is quite difficult to use directly with JNA. I have had some success creating a custom DLL to call these API's (eg. using the SHGetPropertyStoreForWindow to set a different app ID for a submodule window) which I then use JNA to access at runtime.

Try to use JSmooth. I use always this one. In JSmooth is there an option under Skeleton by Windowed Wrapper called
Lauch java app in exe process
See on this image.
(source: andrels.com)
Also command line arguments can be passed.
I think this can be a solution for you.
Martijn

SetCurrentProcessExplicitAppUserModelID (or SetAppID()) would in fact do what you're trying to do. However, it might be easier to modify your installer to set the AppUserModel.ID property on your shortcut - quoting from the Application User Model ID document mentioned above:
In the System.AppUserModel.ID property of the application's shortcut file. A shortcut (as an IShellLink, CLSID_ShellLink, or a .lnk file) supports properties through IPropertyStore and other property-setting mechanisms used throughout the Shell. This allows the taskbar to identify the proper shortcut to pin and ensures that windows belonging to the process are appropriately associated with that taskbar button.
Note: The System.AppUserModel.ID property should be applied to a shortcut when that shortcut is created. When using the Microsoft Windows Installer (MSI) to install the application, the MsiShortcutProperty table allows the AppUserModelID to be applied to the shortcut when it is created during installation.

The latest jna-platform library now includes JNA bindings for SetCurrentProcessExplicitAppUserModelID:
https://github.com/java-native-access/jna/pull/680

I fixed mine without any ID settings.
There is an option in Launch4J if you are using it and you say you do then...
You can change the header to JNI Gui and then wrap it around the jar with the JRE.
The good thing is that it runs .exe in the process now instead on running javaw.exe with your jar. It probably does it under the hood (not sure).
Also I have noticed also that it takes around 40-50% less CPU resource which is even better!
And the pinning works fine and all that window features are enabled.
I hope it helps to someone as I spent nearly 2 days trying to solve that issue with my undecorated javafx app.

Problem with ImageTools plugin in Grails

i have a grails project with an Image Domain Class and Controller.
I just installed the grails ImageTools 1.0.4 Plugin and i would like to generate thumbnails for images wich will be uploaded.
My Image-Domain-Class:
class Image {
byte[] data
//String name
byte[] thumbnail
static constraints = {
//name()
data()
}
}
The "safe"-action in my Controller:
def save = {
def imageInstance = new Image(params)
def imageTool = new ImageTool()
imageTool.load(imageInstance.data)
imageTool.thumbnail(320)
imageInstance.thumbnail = imageTool.getBytes("JPEG") //Here is my problem!
if(!imageInstance.hasErrors() && imageInstance.save()) {
flash.message = "Image ${imageInstance.id} created"
redirect(action:show,id:imageInstance.id)
}
else {
render(view:'create',model:[imageInstance:imageInstance])
}
}
When I start my Grails-application and uploading an image I'm getting the following error-message:
Error 200: groovy.lang.MissingMethodException: No signature of method: ImageTool.getBytes() is applicable for argument types: (java.lang.String) values: {"JPEG"}
Servlet: grails
URI: /grailsproject/grails/image/save.dispatch
Exception Message: No signature of method: ImageTool.getBytes() is applicable for argument types: (java.lang.String) values: {"JPEG"}
Caused by: groovy.lang.MissingMethodException: No signature of method: ImageTool.getBytes() is applicable for argument types: (java.lang.String) values: {"JPEG"}
Class: GrailsAuthenticationProcessingFilter
At Line: [57]
It says that the Method getBytes() is missing but the method is still available. My IDE intelliJ also recognizes no errors.
So what can I do? Could someone help me please?
Sorry for my bad english. If you are german, please look at http://support-network.info/board/problem-mit-imagetools-getbytes-t3008.html .

I use Grails 1.0.4.
I could fix this error message. I just copied the getBytes() method from the git Repository of Ricardo (the plugin developer) and replaced the old one with the new one. Now everything works! I don't know where the bug was but i'm happy that i solved it.
Thank you both very much!

Looks like that method is a fairly new addition to the class (3/6/2009). If you have verified that that method is in the ./plugins/imagetools/src/groovy/ImageTool.groovy file I'd recommend running:
grails clean
If you had been using this plugin prior it might be a cache problem.

The reply that you received from John sounds about right - if you have installed the new plugin and can see the code, but keep getting this error only outside IntelliJ, you should try cleaning your grails cache - it's very possible that an older copy of the plugin is precompiled on the cache.
Are you using Grails 1.1? I haven't yet tested it with the latest grails, but I understand it keeps the plugins not under the project but in a separate directory. Do let me know and I'll try it out.

I don't know what the plugin is really giving you over using JAI directly, IMHO it isn't doing much.
I use ImageMagick out of process for my image conversion and the results are superior to what can be done with JAI from what I have seen. Of course if your doing as much traffic as Amazon running out of process is not an option, however if you need to get to revenue as quickly as possible then you might want to consider what I've done.
I use apache-commons-exec to have a nice interface around handling opening an external process and reading data from std in and out. The only thing I'm using JAI for is to read the sizes of images.

try this one http://support-network.info/board/gel%C3%B6st-problem-mit-imagetools-getbytes-t3008.html