07-03 17:26:44.640 20371-20371/com.wangpan.codebook D/AndroidRuntime: Shutting down VM
07-03 17:26:44.649 20371-20371/com.wangpan.codebook E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.wangpan.codebook, PID: 20371
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.wangpan.codebook/com.wangpan.codebook.ui.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.File android.content.Context.getDatabasePath(java.lang.String)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2811)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2889)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1612)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6621)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:543)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:818)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.File android.content.Context.getDatabasePath(java.lang.String)' on a null object reference
at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:292)
at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:262)
at com.wangpan.codebook.db.dao.DatabaseManager.query(DatabaseManager.java:66)
at com.wangpan.codebook.ui.MainActivity.initView(MainActivity.java:111)
at com.wangpan.codebook.ui.MainActivity.onCreate(MainActivity.java:104)
at android.app.Activity.performCreate(Activity.java:7098)
at android.app.Activity.performCreate(Activity.java:7089)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1215)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2764)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2889)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1612)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6621)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:543)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:818)
折腾了半天,是因为初始化SQLiteOpenHelper时,传入的context不对,导致创建db失败,报上面这个错误。
07-03 17:26:44.649 20371-20371/com.wangpan.codebook E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.wangpan.codebook, PID: 20371
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.wangpan.codebook/com.wangpan.codebook.ui.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.File android.content.Context.getDatabasePath(java.lang.String)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2811)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2889)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1612)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6621)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:543)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:818)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.File android.content.Context.getDatabasePath(java.lang.String)' on a null object reference
at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:292)
at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:262)
at com.wangpan.codebook.db.dao.DatabaseManager.query(DatabaseManager.java:66)
at com.wangpan.codebook.ui.MainActivity.initView(MainActivity.java:111)
at com.wangpan.codebook.ui.MainActivity.onCreate(MainActivity.java:104)
at android.app.Activity.performCreate(Activity.java:7098)
at android.app.Activity.performCreate(Activity.java:7089)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1215)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2764)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2889)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1612)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6621)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:543)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:818)
折腾了半天,是因为初始化SQLiteOpenHelper时,传入的context不对,导致创建db失败,报上面这个错误。