android strictmode有什么作用,Android StrictMode policy

问题

Running into some ANR issues with an android application so I implemented the StrictMode policies. Never used this before so hopefully someone can help explain the following:

Why does the log show 2 violations which are seemingly similar apart from a difference in the top 4 line and the duration? And why are there 2 violations anyway – does this mean that the code was executed twice?

Any help appreciated

08-15 14:24:14.314: DEBUG/StrictMode(767): StrictMode policy violation; ~duration=13876 ms: android.os.StrictMode$StrictModeDiskWriteViolation: policy=17 violation=1

at android.os.StrictMode$AndroidBlockGuardPolicy.onWriteToDisk(StrictMode.java:732)

at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1791)

at com.j256.ormlite.android.AndroidCompiledStatement.execSql(AndroidCompiledStatement.java:151)

at com.j256.ormlite.android.AndroidCompiledStatement.runUpdate(AndroidCompiledStatement.java:70)

at com.j256.ormlite.stmt.StatementExecutor.update(StatementExecutor.java:382)

at com.j256.ormlite.dao.BaseDaoImpl.update(BaseDaoImpl.java:374)

at conx.Repositories.JobRepository.update(JobRepository.java:381)

at conx.Presenters.JobSchedulePresenter.onSave(JobSchedulePresenter.java:200)

at conx.Activities.JobScheduleActivity.onSaveEvent(JobScheduleActivity.java:111)

at conx.Activities.JobScheduleActivity.access$100(JobScheduleActivity.java:43)

at conx.Activities.JobScheduleActivity$2.onChildClick(JobScheduleActivity.java:169)

at android.widget.ExpandableListView.handleItemClick(ExpandableListView.java:588)

at android.widget.ExpandableListView.performItemClick(ExpandableListView.java:527)

at android.widget.AbsListView$PerformClick.run(AbsListView.java:1877)

at android.os.Handler.handleCallback(Handler.java:587)

at android.os.Handler.dispatchMessage(Handler.java:92)

at android.os.Looper.loop(Looper.java:130)

at android.app.ActivityThread.main(ActivityThread.java:3835)

at java.lang.reflect.Method.invokeNative(Native Method)

at java.lang.reflect.Method.invoke(Method.java:507)

at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:864)

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:622)

at dalvik.system.NativeStart.main(Native Method)

08-15 14:24:14.314: DEBUG/StrictMode(767): StrictMode policy violation; ~duration=12086 ms: android.os.StrictMode$StrictModeDiskWriteViolation: policy=17 violation=1

at android.os.StrictMode$AndroidBlockGuardPolicy.onWriteToDisk(StrictMode.java:732)

at android.database.sqlite.SQLiteStatement.execute(SQLiteStatement.java:52)

at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1809)

at com.j256.ormlite.android.AndroidCompiledStatement.execSql(AndroidCompiledStatement.java:151)

at com.j256.ormlite.android.AndroidCompiledStatement.runUpdate(AndroidCompiledStatement.java:70)

at com.j256.ormlite.stmt.StatementExecutor.update(StatementExecutor.java:382)

at com.j256.ormlite.dao.BaseDaoImpl.update(BaseDaoImpl.java:374)

at conx.Repositories.JobRepository.update(JobRepository.java:381)

at conx.Presenters.JobSchedulePresenter.onSave(JobSchedulePresenter.java:200)

at conx.Activities.JobScheduleActivity.onSaveEvent(JobScheduleActivity.java:111)

at conx.Activities.JobScheduleActivity.access$100(JobScheduleActivity.java:43)

at conx.Activities.JobScheduleActivity$2.onChildClick(JobScheduleActivity.java:169)

at android.widget.ExpandableListView.handleItemClick(ExpandableListView.java:588)

at android.widget.ExpandableListView.performItemClick(ExpandableListView.java:527)

at android.widget.AbsListView$PerformClick.run(AbsListView.java:1877)

at android.os.Handler.handleCallback(Handler.java:587)

at android.os.Handler.dispatchMessage(Handler.java:92)

at android.os.Looper.loop(Looper.java:130)

at android.app.ActivityThread.main(ActivityThread.java:3835)

at java.lang.reflect.Method.invokeNative(Native Method)

at java.lang.reflect.Method.invoke(Method.java:507)

at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:864)

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:622)

at dalvik.system.NativeStart.main(Native Method)

回答1:

The StrictMode violation is showing that you are executing an SQLite query on the UI thread which is causing the ANR issues.

Try performing database interactions on a separate thread, this will prevent the ANR issues and prevent these StrictMode violations showing.

From skimming through that LogCat output it looks like it’s occuring in conx.Activities.JobScheduleActivity.onSaveEvent

Some useful reading:

http://developer.android.com/guide/components/processes-and-threads.html

http://www.vogella.com/articles/AndroidPerformance/article.html

来源：https://stackoverflow.com/questions/11963601/android-strictmode-policy