Asked 23/9, 2011 at 13:14 Answered 10/5, 2017 at 7:22

Has someone tried to use MessagePack with an Android app?
Is it possible? I have tried to use the Jar from msgpack-java and received the following Exception:

Caused by: java.lang.ExceptionInInitializerError
  at org.msgpack.Packer.pack(Packer.java:532)
  at org.msgpack.MessagePack.pack(MessagePack.java:31)
  ... 15 more
  Caused by: java.lang.ExceptionInInitializerError
  at org.msgpack.template.TemplateRegistry.<clinit>(TemplateRegistry.java:38)
  ... 17 more
  Caused by: java.lang.VerifyError: org.msgpack.template.BeansFieldEntryReader
  at org.msgpack.template.builder.BeansTemplateBuilder.<init (BeansTemplateBuilder.java:42)
  at org.msgpack.template.builder.BuilderSelectorRegistry.initForJava(BuilderSelectorRegistry.java:73)
  at org.msgpack.template.builder.BuilderSelectorRegistry.<clinit>(BuilderSelectorRegistry.java:38)
  ... 18 more

The code that I use is very simple

PrintWriter out = new PrintWriter(socket.getOutputStream());
Message msg = new Message();
msg.body = "asdasdasd";
msg.from = "qwe";
msg.to = "ttt";
byte[] bytes = MessagePack.pack(msg);
out.print(bytes);
out.flush();

I have javassist.jar, msgpack-0.5.2.jar, slf4j-api-1.6.2.jar and slf4j-jdk14-1.6.2.jar in my lib directory.

In my server application this code works fine with the same libraries.

Smedley answered 23/9, 2011 at 13:14 Comment(4)

Is this the full stack trace you get? ExceptionInInitializerError is caused by some exception which happens during loading of the class, so there has to be something else as there isn't any class loading happening in your stack trace. – Gio 23/9, 2011 at 13:33

No, i edited my post, so it's almost full stack (a deleted a part with java.lang.IllegalStateException: Could not execute method of the activity, it's not so informative) – Smedley 23/9, 2011 at 13:50

Please post the entire stack trace – Micronesian 23/9, 2011 at 16:14

I hope this may be helpful, :), github.com/chzyer/msgpack-for-android – Pease 28/12, 2012 at 23:11

(Hopefully) FINAL UPDATE

msgpack : 0.6.8 works on Android without any problems

msgpack-rpc : 0.7.0 works on Android with one caveat.

Specifically, you need to add the following to onCreate for API Level 8 (Android 2.2.1), and possibly lower:

java.lang.System.setProperty("java.net.preferIPv4Stack", "true");
java.lang.System.setProperty("java.net.preferIPv6Addresses", "false");

due to this bug.

If you want to see a simple example, here's a pair of projects set up for this purpose:

Previous Versions

UPDATE: as of 0.6.7 msgpack should be compatible with Android (there is a small dependency exclusion issue). Check the text below for msgpack-rpc (which also might be adapted in the future).

NOTE: If you're also using msgpack-rpc, you need to do the following steps:

Download the msgpack-rpc source from git://github.com/msgpack/msgpack-rpc.git (specifically, the "java" folder).
Change the main msgpack artifact version to the one you've built.
In org.msgpack.rpc.loop.netty.NettyEventLoop, change the NioClientSocketChannelFactory to OioClientSocketChannelFactory(getWorkerExecutor()).
Build the MessagePack-RPC in the same way as in the case of the main MessagePack JAR (see Step 11 above).

The NettyEventLoop replacement is due to this issue: http://markmail.org/message/ypa3nrr64kzsyfsa .

Important: I've only tested synchronous communication. Asynchronous might not work.

And here's the reason for msgpack not working with Android prior to 0.6.7:

The reason for the error is that MessagePack uses several java.beans classes that are not included in the Android SDK. You're probably using the MessagePackBeans annotation.

This is a similar problem to the one described here, for which the general solution is outlined here. Unfortunately, in our case it requires a rebuild of msgpack. Here's what I did (you can almost certainly skip Steps 5 and 8, but I haven't tried it that way) :

Download the MessagePack source from https://github.com/msgpack/msgpack-java.git.
Import the MessagePack source as a project in your IDE.
Download the Apache Harmony source for the relevant packages from http://svn.apache.org/repos/asf/harmony/enhanced/java/trunk/classlib/modules/beans/src/main/java .
Copy these packages into your MessagePack project's src/main/java folder:
- java.beans
- java.beans.beancontext
- org.apache.harmony.beans
- org.apache.harmony.beans.internal.nls
In your MessagePack project, remove the following classes:
- PropertyChangeListener
- IndexedPropertyChangeEvent
- PropertyChangeEvent
- PropertyChangeListenerProxy
- PropertyChangeSupport
Rename the java.beans packages to something different, e.g. custom.beans .
Change all java.beans references to the renamed ID, so again e.g. custom.beans. This applies especially to BeansFieldEntryReader (this class is the reason for the original error).
Change the custom.beans references for the five classes you removed in Step 5 back to java.beans.
In the org.apache.harmony.beans.internal.nls.Messages class, comment out the method setLocale, and remove the imports associated with it.
Remove all classes that still have errors, except Encoder. In that class, comment out all references to the classes you've removed. You should now have an error-free project.
Build the MessagePack JAR:
- If you're using Maven, change the version in the pom.xml to something unique, run Maven build with the install goal, then add the dependency in your Android project with that version.
- If you're not using Maven, you have to run the jar goal for Ant with the included build.xml. Replace the msgpack JAR in your Android project with this one.
If you're publishing your app, remember to include the relevant legal notice for Apache Harmony. It's an Apache License, just like MessagePack.

That should do it. Using your example code, and my own data class, I was successfully able to pack and unpack data.

The entire renaming ritual is due to the fact that the DEX compiler complains about java.* package naming.

Reprobate answered 2/10, 2011 at 1:40 Comment(3)

You're welcome - it was a bit of a PITA, but it definitely works :). FYI, I've added a relevant post in MessagePack's user group: groups.google.com/group/msgpack/browse_thread/thread/… . – Silvery 4/10, 2011 at 22:36

@TheTerribleSwiftTomato Do you think the same would be possible to port javax.xml.bind.JAXBElement to Android? My question is here. – Carolecarolee 27/4, 2012 at 14:50

@Reprobate Looks like it still uses non-Android packages. Lint says:

Invalid package reference in library; not included in Android: java.applet. Referenced from javassist.tools.rmi.ObjectImporter.

and

Invalid package reference in library; not included in Android: javax.tools. Referenced from org.msgpack.util.TemplatePrecompiler.

– Chingchinghai 10/11, 2015 at 12:44

There is a critical msgpack bug saying data packed with msgpack will get corrupted on the Dalvik VM. http://jira.msgpack.org/browse/MSGPACK-51

Earthshaker answered 31/10, 2011 at 22:6 Comment(1)

I'm reasonably certain you can work around it by using @MessagePackBeans instead. That's what I used in testing. – Silvery 5/11, 2011 at 16:37

There is an ongoing effort by @TheTerribleSwiftTomato and the MessagePack core team to get MessagePack working on Android, please see the related GitHub issue. The fix mentioned in @TheTerribleSwiftTomato's answer is to be found here.

Update

I've managed to get it at least running on Android by (painstakingly) adding all the necessary javassist Classes which are currently required for the build to succeed. An extra 600KB gain in size, yet at least it seems to work. All in all, it appears to be working to some extent on Android, eventually check out the lesser-known resources about Message Pack such as its User Group and its Wiki for more information.

On a side-note, be sure to use a HTTP Request Library (such as LoopJ's Android Async HTTP or Apache's HttpClient) which can handle binary data.

Last but not least you can ping me if there is interest in this jar which makes MessagePack seemingly work on Android – credits go out of course to @TheTerribleSwiftTomato who supplied the fix above!

Facetious answered 15/8, 2012 at 6:43 Comment(4)

Still have the same problem, any help ? – Sfax 1/8, 2013 at 9:49

Google me and write an e-mail, I'll get back to you this evening and mail you the .jar which worked for me. Although the issue seems to be resolved in MessagePack, see github.com/msgpack/msgpack-java/issues/15 – Facetious 1/8, 2013 at 10:19

it gives me java.lang.NoClassDefFoundError: org.msgpack.MessagePack – Sfax 1/8, 2013 at 16:36

Ok, did you perhaps forget to add the MessagePack .jar within your Classpath? (In Eclipse, use Project Properties » Libraries and Code » External Libraries » Add External JAR [from the top of my head]) – Facetious 2/8, 2013 at 6:19

I suggest you write this in the main proguard-rules file-

-dontwarn org.msgpack.**
-keep class org.msgpack.** { *; }

Yetta answered 10/5, 2017 at 7:22 Comment(0)

(Hopefully) FINAL UPDATE

Previous Versions

Recommended topics

Hot tags