Is there a java api similar to RAPI? I want to be able to access files on the windows mobile device using a java desktop program.
Thanks.
You could use RAPI itself, and access it from Java using JNI or a wrapper like Swig
We were also looking for a similar API in Java but unfortunately none is available. I wrote my own RAPI wrapper using JNI and used that in my program.
The main problem with JNI is that any un-handled exceptions/faults cause the calling Java program to shutdown as well. Do keep that in mind when writing your wrapper. There are different approaches to safe guard these, the simplest and common approach is to write a standalone program written in .Net/C++ that communicates with the RAPI and your Java program communicates with that program using pipes/files etc. this way you also don't have to write a JNI wrapper :-)
Related
I have existing cpp files from a project which I would like to use it for my application which is in Java. I cannot change the cpp files. How can I call the functions from Java?
I'm working in Windows 10 using JavaFX for my application. I've seen some articles about JNI but none seem to solve my issue.
If JNI or swig is not desired or seems too low level,
A really blunt approach is to wrap the .cpp in c/c++ program and built an .exe that dumps to stdout/file. Then execute that in java via an external shell command.
Another good alternative is
Apache thrift
This basicly handles everything and goes everywhere so to speak (works by auto-generating code to target languages) and it is one I usually recommend in RPC situations. However there could be more setup cost involved (in the end, depends on your actual needs) - also since you need to host the .cpp in a service, in your case, locally.
If you package your library inside a shared object or a dll, you can also use JNA: https://github.com/java-native-access/jna or https://github.com/java-native-access/jna/blob/master/www/GettingStarted.md
For example, you already have mapping to Windows API.
Another example is a mapping of mediainfo in Java: https://github.com/andersonkyle/mediainfo-java-api/blob/master/src/main/java/org/apothem/mediainfo/api/MediaInfo.java
Note that, as far as I understand it, this is based on JNI: it simplify the process since you mostly have to only declare interface on Java side and call appropriate method.
I'm trying to write a plugin for a Java Application. The plugin should be able to tell the Java Application that new events have been recognized (Observer Design Pattern, Polling ... thats not the point). The problem is that the events are tracked gestures coming from a Microsoft Kinect controller (I´m using C++ and the Microsoft Kinect SDK because I have to). So that means I have to communicate between the Java Application and my Kinect Application.
I thought of something like an adapter design pattern where the Java application is "including" the interface (c++ header file, dll etc.). First I thought of JNI but then I have to write a DLL that will be used on both application sides, right? Another thing I thought of was to provide the gesture data via a protocol like UDP (or something more lightweight?). The last thing I heard of was to write a COM+ assembly ... but to be honest my knowledge about COM+ is rather little.
JAVA APPLICATION << ----- ??? ----- >> KINECT APPLICATION
May be you should have a look at google's Protocol Buffers.
Since you are considering JNI.
I'd suggest you refer to this IBM tutorial.
JNI allows the java application to call c/c++ methods and vice-versa.
Also have a look at this
question, if you are calling java from c++.
I have found some examples such as here, here and here which recommend you either used a shared memory structure or else use sockets.
I think that in this case, letting your programs communicate through sockets would be the best idea since your applications will not be that tightly coupled, so you just need to expose an IP, a port and a set of commands.
According to this it seems possible to create a C++ server on the Kinect, but other than that I can't say much since I have never worked on Kinect related projects.
JNI (Java Native Interface) allows the java application to call c/c++
methods.
All this requires that we have a means of communicating (Integrating Java
with C++) between Java and C++. This is provided by the JNI (Java Native
Interface).
For a practical example of using the JNI and calling native methods from Java, see this InfoWorld article.
I need to get control over Windows of WindowsXP using Java code,
I need to click/type on particular button/textfield of given window of windowsXP,
How to do this any idea?
Approaches I tried are:
(1) I Tried AutoIT framework, but its Java Wrapper is buggy.. not stable.
(2) JNA can be used for native interfacing, by using some .dll file
to achieve the same. But I don't know which .dll file is used by windowsXP.
Can anybody elaborate on this?
I've not much idea which is much better solution.
Is there any better framework available for such thing.
Thanks.
WindowsXP uses multiple dll files, not one, and studying its API will tell you which one has which functions, and then you can use this information in your JNA interaction code. BTW, I have use AutoIt by itself to help do what you're trying to do and it works fine, and is easier than Java with JNA since it's built for this sort of thing. I've also used AutoIt with Java by having Java call small AutoIt programs and get some simple interaction via standard input and output streams taking care though of the tips and traps in this great article: When Runtime.exec() won't
I am developing a Java application in which I need to call some C++ functions (from Google Talk library libjingle) . The objective is to run it all on Google App Engine (which only supports Python or Java).
How can I do this?
You need to define native methods in your java code for whatever you want to be implemented in C++ and directly access your native code. Then you run javah on your code and it will generate the C header files for you and you'll need to provide C++ implementations.
The native methods you can call from your Java code like any other methods and still they'll have their implementation written in C++ and talking to whatever other native library directly.
You then need to set the java.library.path system property to include the shared C/C++ libraries that you require: the google library and your own JNI implementation library would be required in this case.
If the library has C bindings through a DLL/SO, I usually prefer writing wrappers in Java using Java Native Access (JNA) rather than writing the bindings in C/C++ using the Java Native Interface (JNI). The former is easier to manipulate as the JNI access to Java objects is a real pain in the neck. However, it's not as obvious to wrap C++ classes using that API.
You might also want to look into the Simplified Wrapper and Interface Generator (SWIG) for automating part of this process!
You can't run native code on App Engine - only JRE code. If there's no avoiding the native code, you'll need to run this part of your app on another system, and call it from your App Engine app - or use the built-in XMPP API, in this case.
I have a Java app that takes a long time to be initialized (so I can't use a command-line like interface) and I need to pass text and receive the output of a Java method from Python. Is it possible to load the Java application, have it open all the time the Python script runs and use a method from that app?
I don't think the use of Python helps all that much over a command line (at least not a *nix command line), but the basic idea is to communicate over a socket or some similar mechanism. That means that the Java application will have to be wrapped in some code which opens a socket and waits for the python script to contact it. If you are most comfortable with python, you could look to implement that wrapper in Jython.
I've used JPype for something similar and it worked great.
JPype is an effort to allow python programs full access to java class libraries. This is achieved not through re-implementing Python, as Jython/JPython has done, but rather through interfacing at the native level in both Virtual Machines.
If the java app is running you should also consider xml-rpc as it also works well.
Py4J is a way to call Java from a python script. Here is the project website: http://py4j.sourceforge.net/