android.os.NetworkOnMainThreadException

[kaifeichen]

The socket operation in BosswaveClient constructor causes

android.os.NetworkOnMainThreadException

when called in Android main thread.

Should the socket be moved to another thread (like the beginning of the listener thread?)? Or should application developer avoid creating BosswaveClient in the main thread?

Android log:

D/libc-netbsd: [getaddrinfo]: hostname=xxxxx; servname=(null); cache_mode=(null), netid=0; mark=0
D/libc-netbsd: [getaddrinfo]: ai_addrlen=0; ai_canonname=xxxxx; ai_flags=4; ai_family=0
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: edu.berkeley.cs.sdb.cellmate, PID: 9339
                  java.lang.RuntimeException: Unable to start activity ComponentInfo{edu.berkeley.cs.sdb.cellmate/edu.berkeley.cs.sdb.cellmate.MainActivity}: android.os.NetworkOnMainThreadException
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2345)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2405)
                      at android.app.ActivityThread.access$800(ActivityThread.java:155)
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1323)
                      at android.os.Handler.dispatchMessage(Handler.java:102)
                      at android.os.Looper.loop(Looper.java:135)
                      at android.app.ActivityThread.main(ActivityThread.java:5376)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at java.lang.reflect.Method.invoke(Method.java:372)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)
                   Caused by: android.os.NetworkOnMainThreadException
                      at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1147)
                      at java.net.InetAddress.lookupHostByName(InetAddress.java:426)
                      at java.net.InetAddress.getAllByNameImpl(InetAddress.java:255)
                      at java.net.InetAddress.getAllByName(InetAddress.java:218)
                      at java.net.Socket.tryAllAddresses(Socket.java:111)
                      at java.net.Socket.<init>(Socket.java:180)
                      at java.net.Socket.<init>(Socket.java:152)
                      at edu.berkeley.cs.sdb.bosswave.BosswaveClient.<init>(BosswaveClient.java:50)
                      at edu.berkeley.cs.sdb.cellmate.MainActivity.initBosswaveClient(MainActivity.java:482)
                      at edu.berkeley.cs.sdb.cellmate.MainActivity.onCreate(MainActivity.java:419)
                      at android.app.Activity.performCreate(Activity.java:6021)
                      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2405) 
                      at android.app.ActivityThread.access$800(ActivityThread.java:155) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1323) 
                      at android.os.Handler.dispatchMessage(Handler.java:102) 
                      at android.os.Looper.loop(Looper.java:135) 
                      at android.app.ActivityThread.main(ActivityThread.java:5376) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at java.lang.reflect.Method.invoke(Method.java:372) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)

Ref: https://github.com/SoftwareDefinedBuildings/bw2android/blob/master/src/main/java/edu/berkeley/cs/sdb/bosswave/BosswaveClient.java#L50

[jhkolb]

I'll look into it.

Why didn't this error show up for you until now? What's changed in the code?