how-to-create-mutable-java-lang-string

2012, 17 years since java born: how-to-create-mutable-java-lang-string

Ubuntu x64, avd device creation error

in order to use android sdk in ubuntu (12.04) x64 you need to install x32 java libraries (~270mb), otherwise: Error: Failed to create the SD card

netty 3.5.1 bundle in Felix 3.2.1 osgi Container = ClassNotFoundException

netty 3.5.1 started in osgi (felix 3.2.1):

...
[org.jboss.netty.util.internal.QueueFactory] - Unable to instance LinkedTransferQueue, fallback to LegacyLinkedTransferQueue
java.lang.NoClassDefFoundError: Could not initialize class org.jboss.netty.util.internal.LinkedTransferQueue
 at org.jboss.netty.util.internal.QueueFactory.createQueue(QueueFactory.java:53) ~[na:na]
 at org.jboss.netty.channel.socket.nio.AbstractNioWorker.(AbstractNioWorker.java:111) ~[netty-3.5.1.Final.jar:na]
 at org.jboss.netty.channel.socket.nio.NioWorker.(NioWorker.java:44) ~[netty-3.5.1.Final.jar:na]
 at org.jboss.netty.channel.socket.nio.NioWorkerPool.createWorker(NioWorkerPool.java:34) ~[netty-3.5.1.Final.jar:na]
 at org.jboss.netty.channel.socket.nio.NioWorkerPool.createWorker(NioWorkerPool.java:26) ~[netty-3.5.1.Final.jar:na]
 at org.jboss.netty.channel.socket.nio.AbstractNioWorkerPool.(AbstractNioWorkerPool.java:58) ~[netty-3.5.1.Final.jar:na]
 at org.jboss.netty.channel.socket.nio.NioWorkerPool.(NioWorkerPool.java:29) ~[netty-3.5.1.Final.jar:na]
 at org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory.(NioClientSocketChannelFactory.java:149) ~[netty-3.5.1.Final.jar:na]
 at org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory.(NioClientSocketChannelFactory.java:114) ~[netty-3.5.1.Final.jar:na]
...

If you debug and dig into netty source code - you'll find more descriptive exception: java.lang.ClassNotFoundException: sun.misc.Unsafe not found by org.jboss.netty

The problem seems that osgi container doesn't normally expose sun.misc.* internals, so the application cannot find it, though it's Oracle Jdk 1.6 with this stuff inside.

Looking further to the source code - you'll find the workaround: -Dorg.jboss.netty.tryUnsafe=false

p.s. issue discussion on the netty github tracker

yet another gotcha this week )

when running scp task from ant (1.8) script - you need place jsch-0.1.48.jar to ant classpath (via IDE e.g.), otherwise you'll get "class org.apache.tools.ant.taskdefs.optional.ssh.Scp was not found" (SO).

And in case of running it from maven - instead of standart form:

          
                maven-antrun-plugin
                1.7
                
                    
                        deploy
                        
                            
                                
                                       ....
                                
                            
                        
                        
                            run
                        
                    
                
            

you'll need to add the following dependencies:

          
                maven-antrun-plugin
                1.7

                
                    
                        org.apache.ant
                        ant-jsch
                        1.7.0
                    
                    
                        com.jcraft
                        jsch
                        0.1.48
                    
                

                
                    
                        deploy
                        
                            
                                
                                       ....
                                
                            
                        
                        
                            run
                        
                    
                
            

otherwise you'll get in maven smth like that:


[ERROR] Failed to execute goal org.apache.maven.plugins:maven-antrun-plugin:1.7:run (default) on project ...
ildException has occured: Problem: failed to create task or type scp
[ERROR] Cause: the class org.apache.tools.ant.taskdefs.optional.ssh.Scp was not found.
[ERROR] This looks like one of Ant's optional components.
[ERROR] Action: Check that the appropriate optional JAR exists in
[ERROR] -ANT_HOME\lib
[ERROR] -the IDE Ant configuration dialogs
[ERROR]
[ERROR] Do not panic, this is a common problem.
[ERROR] The commonest cause is a missing JAR.
[ERROR]
[ERROR] This is not a bug; it is a configuration problem
[ERROR]
[ERROR] around Ant part ...<scp ....
[ERROR] -> [Help 1]

faced gotcha

you must use special openssh format key when running scp from ant: http://netpenthe.wordpress.com/2007/02/02/jschexception-invalid-privatekey-ant-scp/

faced gotcha

If you use osgi - you can't load property files from classpath as usial, +SO

faced gotcha: puzzle with google account in android emulator

When creating your device in AVD - if you select configuration by android version like android 2.2 - you 'll fail to add google account on it ))

Only if you select device configuration by Google API Version (like API Level 8) - you'll get an ability to have google/gmail sign-on on you emulator. Quite a funny.

- related SO question.