Crash问题分析定位:通过Log文件夹下全局搜am_crash,此时会把log文件下下所有的包含am_crash的行显示出来
一.导致Android Crash 问题的主要类型
JAVA application crash
1.ANR(application no response) crash
2.JAVA uncaught exception crash
System crash
1.Process Crash(Native Crash or C/Delvik Crash)
2.Kernel Crash
3.Modem Crash
1) HW Watchdog
2)SW Watchdog
3)Apps Keepalive
4)Other
由上图可见,在APP层面我们出现并能解决的BUG 集中在App Crash 和System crash 层;
二. ANR(application no response)
(一)导致ANR主要有3种原因:
ANR的产生原因就是由于应用程序的主线程响应超时导致的,只要超过最大限制的超时时间就必然会产生ANR:
1.KeyDispatchTimeout(5 seconds)–按键或触摸事件在特定时间内无响应;(输入事件)
2. BroadcastTimeout(10 seconds)–BroadcastReceiver在特定时间内无法处理完成;(特定操作)
3. ServiceTimeout(20 seconds)–Service在特定的时间内无法处理完成;(特定操作)
(二)处理方法
1.获取实时log: adb logcat -v time >anr.log 或 adb logcat -v time | tee anr.log
2.获取traces.txt文件:adb pull /data/anr/traces.txt C:\monkey
(三)分析log
从log可以看出ANR的类型:
1.cpu使用量接近100%,说明当前设备很忙,有可能是cpu饥饿导致ANR;
2.cpu使用量很低,说明主线程有可能被阻塞;
3.IOwait很高,说明有可能是主线程在进行I/O操作导致ANR;
(四)分析traces
三. Java Crash
(一)Error and exception 的区别
Error(错误):表示系统级的错误和程序不必处理的异常,是java运行环境中的内部错误或者硬件问题,比如,内存资源不足等,对于这种错误,程序基本无能为力,除了退出运行外别无选择;
Exception(异常):表示需要捕捉或者需要程序进行处理的异常,它处理的是因为程序设计的瑕疵而引起的问题或者在外的输入等引起的一般性问题,是程序必须处理的;
(二)常见Java Error and exception
1.现象:系统弹出窗口提示用户某进程崩溃或者直接闪退;
2.Throwable类是Java语言中所有错误或异常的超类;
(1).Error
a.OutOfMemory
b.IOError
c.StackOverflowError
d.UnsatisfiedLinkError
e.其它Error…;
常见Error列表:
(2).Exception
a.RuntimeException (最常见)
b.Checked(编译时检查)
c.其它Exception…;
常见Exception列表:
-----------------------------------------------------------------下面是各种Crash 案例分析------------------------------------------------------
一、NullPointerException 空指针
1. 数组 NullPointerException
不能向一个
2. 数组NullPointerException 代码举例
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | public static void ArrayNullPointer() { /** * 数组空指针 NullPointerException * * 1.获取null数组长度 * 2.为null 数组元素复制 * */ int[] array = null; // 1. NullPointerException: Attempt to get length of null array int length = array.length; // 2. NullPointerException: Attempt to write to null array array[0] = 1; } |
NullPointerException 代码举例
3. 数组NullPointerException Log 举例
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Log 信息如下
获取 空数组长度导致的
1 2 3 4 5 | 12-27 17:17:44.627 8839 8839 E AndroidRuntime: Caused by: java.lang.NullPointerException: Attempt to get length of null array 12-27 17:17:44.627 8839 8839 E AndroidRuntime: at com.programandroid.Exception.NullPointerException.ArrayNullPointer //产生空指针代码行 (NullPointerException.java:32) |
4. Log 分析如下
数组NullPointerException
空数组无法获取下标内容,如果获取则会导致
1 2 3 | 12-27 17:23:24.168 11649 11649 E AndroidRuntime: Caused by: java.lang.NullPointerException: Attempt to write to null array 12-27 17:23:24.168 11649 11649 E AndroidRuntime: at com.programandroid.Exception.NullPointerException.ArrayNullPointer(NullPointerException.java:34) 12-27 17:23:24.168 11649 11649 E AndroidRuntime: at com.programandroid.Exception.ExceptionActivity.NullPointerException(ExceptionActivity.java:37) |
5. Object 对象 NullPointerException
对象空指针,这个是常见的空指针,主要是因为引用一个
6. object 对象 NullPointerException 代码举例
简单代码举例如下:
1 2 3 4 5 | public static void ListNullPointer() { ArrayList<String> mArrayList = null; mArrayList.size(); } |
Object 对象 NullPointerException
7. object 对象 NullPointerException log 举例
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Log 信息如下:
1 2 3 | 12-27 17:28:22.565 12725 12725 E AndroidRuntime: Caused by: java.lang.NullPointerException: Attempt to invoke a virtual method on a null object reference 12-27 17:28:22.565 12725 12725 E AndroidRuntime: at com.programandroid.Exception.NullPointerException.ListNullPointer(NullPointerException.java:45) 12-27 17:28:22.565 12725 12725 E AndroidRuntime: at com.programandroid.Exception.ExceptionActivity.NullPointerException(ExceptionActivity.java:37) |
8. object 对象 NullPointerException Log 分析如下:
Object NullPointerException
9. NullPointerException 解决方案
规避空指针举例如下:
-
1.使用时多注意判断对象是否为空
1 2 3 4 5 6 7 | public static void ListNullPointer() { ArrayList<String> mArrayList = null; if (mArrayList != null) { mArrayList.size(); } } |
使用对象是,最好判断对象是否为空
-
2.使用
try-catch 将抛出的异常抓住
1 2 3 4 5 6 7 8 | public static void ListNullPointer() { try { ArrayList<String> mArrayList = null; mArrayList.size(); } catch (Exception e) { // TODO: handle exception } } |
try-catch 代码异常,防止app crash
二、 ClassCastException 类型转换异常
此异常发生在类型转换时,并且在编译期间,编译器不会提示报错,但是当运行时,如果存在此异常,可能会导致
比如当
1. 以下代码 会引起 ClassCastException
请勿 父类强制转换为子类,否则就会发生
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 | public void ClassCastExample() { Fruit banana = new Fruit(); /** * ClassCastException * * 1. 此处强制转换,会导致 app 编译没问题,运行挂掉, Caused by: * java.lang.ClassCastException: * com.programandroid.Exception.ExceptionActivity$ Fruit cannot be cast * to com.programandroid.Exception.ExceptionActivity$Apple * ***/ Apple apple = (Apple) banana; } /** * ClassCastException * * 2. 此处强转回导致app crash return (Apple) banana; * */ public Apple isRight() { Fruit banana = new Fruit(); return (Apple) banana; } class Fruit { public Fruit() { } } class Apple extends Fruit { public Apple() { } } |
ClassCastException 类型转换异常举例
2. ClassCastException Log 举例
1 2 3 | Caused by: java.lang.ClassCastException: com.programandroid.Exception.ExceptionActivity$ Fruit cannot be cast to com.programandroid.Exception.ExceptionActivity$Apple |
3. ClassCastException Log 分析
ClassCastException log 分析
4. ClassCastException 解决方案
使用
使用 try-catch抓住 ClassCastException异常
5. Android 手机 Settings ClassCastException 解决方案
举例是为了更好的解决开发中的异常。比如在开发中,使用
比如
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log 信息如下:
1 2 3 4 5 6 7 | FATAL EXCEPTION: ApplicationsState.Loader 01-05 03:36:56.101 6304 6941 E AndroidRuntime: Process: com.android.settings, PID: 6304 01-05 03:36:56.101 6304 6941 E AndroidRuntime: java.lang.ClassCastException: com.android.settings.datausage.AppStateDataUsageBridge$DataUsageState cannot be cast to com.android.settings.notification.NotificationBackend$AppRow 01-05 03:36:56.101 6304 6941 E AndroidRuntime: at com.android.settings.applications.AppStateNotificationBridge$3.filterApp(AppStateNotificationBridge.java:110) |
6. Settings ClassCastException Log分析
Settings ClassCastException Log1
Settings ClassCastException Log2
7. Setting crash ClassCastException 解决方案:
try-catch 异常报错的地方
try-catch 异常报错的地方
try-catch 异常报错的地方
三、IndexOutOfBoundsException 下标越界异常
List 在开发中经常会被用的,那么错误的使用下标,将会导致
1. IndexOutOfBoundsException 代码举例
IndexOutOfBoundsException 异常举例
2. IndexOutOfBoundsException Log举例
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Log 信息如下:
1 2 3 4 | 12-27 17:41:24.231 16891 16891 E AndroidRuntime: Caused by: java.lang.IndexOutOfBoundsException: Index: 0, Size: 0 12-27 17:41:24.231 16891 16891 E AndroidRuntime: at java.util.ArrayList.get(ArrayList.java:411) 12-27 17:41:24.231 16891 16891 E AndroidRuntime: at com.programandroid.Exception.IndexOutOfBoundsException.isAppOnRecent(IndexOutOfBoundsException.java:40) 12-27 17:41:24.231 16891 16891 E AndroidRuntime: at com.programandroid.Exception.ExceptionActivity.IndexOutOfBoundsException(ExceptionActivity.java:80) |
3. Log 分析如下:
IndexOutOfBoundsException Log分析
4. IndexOutOfBoundsException 解决方案
在使用时判断对象内容是否为0.
使用判断List 的size是否为0
四、ActivityNotFoundException
主要原因是未在
1. ActivityNotFoundException 代码举例
比如以下代码会引起此异常
Activity未在Androidmainfest.xml 中注册会引起ActivityNotFoundException
2. ActivityNotFoundException Log 举例
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Log信息如下:
1 2 | 12-27 17:46:05.994 17893 17893 E AndroidRuntime: Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.programandroid/com.programandroid.Test.TestActivity}; have you declared this activity in your AndroidManifest.xml? 12-27 17:46:05.994 17893 17893 E AndroidRuntime: at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1810) |
3. Log 分析如下:
ActivityNotFoundException Log分析
4. ActivityNotFoundException 解决方案
在
四大组件一定,一定要在AndroidMainfest.xml 中注册
五、IllegalStateException
以下代码会引起
1. IllegalStateException 代码举例
IllegalStateException 代码举例
2. IllegalStateException Log 举例
-
log信息如下:
1 2 3 4 5 6 7 8 | 12-27 16:07:41.158 1715 1715 E AndroidRuntime: FATAL EXCEPTION: main 12-27 16:07:41.158 1715 1715 E AndroidRuntime: Process: com.programandroid, PID: 1715 12-27 16:07:41.158 1715 1715 E AndroidRuntime: java.lang.IllegalStateException: Could not find method IllegalStateException(View) in a parent or ancestor Context for android:onClick attribute defined on view class android.widget.Button with id 'btn_on_click' 12-27 16:07:41.158 1715 1715 E AndroidRuntime: at android.view.View$DeclaredOnClickListener.resolveMethod(View.java:4781) 12-27 16:07:41.158 1715 1715 E AndroidRuntime: at android.view.View$DeclaredOnClickListener.onClick(View.java:4740) |
3. IllegalStateException Log分析如下:
IllegalStateException Log截图
4. IllegalStateException 解决方案
IllegalStateException
六、 ArrayIndexOutOfBoundsException 数组越界异常
数组在代码中经常被用到,当适用数组下标不当时,就会出现
1. ArrayIndexOutOfBoundsException 代码举例:
1 2 3 4 5 | public static void ArrayIndexOutOfBounds() { String[] mStrings = { "a", "b", "c", "d" }; String testsString = mStrings[5]; } |
ArrayIndexOutOfBoundsException 代码举例
2. ArrayIndexOutOfBoundsException Log举例:
-
Log信息如下:
1 2 3 4 | 12-27 17:51:15.420 19185 19185 E AndroidRuntime: Caused by: java.lang.ArrayIndexOutOfBoundsException: length=4; index=5 12-27 17:51:15.420 19185 19185 E AndroidRuntime: at com.programandroid.Exception.ArrayIndexOutOfBoundsException.ArrayIndexOutOfBounds(ArrayIndexOutOfBoundsException.java:20) 12-27 17:51:15.420 19185 19185 E AndroidRuntime: at com.programandroid.Exception.ExceptionActivity.ArrayIndexOutOfBoundsException(ExceptionActivity.java:105) 12-27 17:51:15.420 19185 19185 E AndroidRuntime: ... 11 more |
3. ArrayIndexOutOfBoundsException Log分析如下:
ArrayIndexOutOfBoundsException Log分析
4. ArrayIndexOutOfBoundsException解决方案
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1.正确使用数组下标
-
2.如果不确定数组长度,请先获取长度,然后在判断下标是否大于等于数组长度。
-
3.try-catch 抓住异常,防止crash,但不能从根本上解决问题。
七、SecurityException 安全异常
1. SecurityException 代码举例
获取手机的IMEI 号属于手机的敏感信息
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | /** * * <!-- 读取手机IMEI的设备权限 --> * * <uses-permission android:name="android.permission.READ_PHONE_STATE" /> * */ public static String getIMEI(Context context) { TelephonyManager tm = (TelephonyManager) context .getSystemService(Context.TELEPHONY_SERVICE); String deviceId = tm.getDeviceId(); if (deviceId == null) { return "UnKnown"; } else { return deviceId; } } |
获取手机IMEI号
2. SecurityException log举例
1 2 3 4 | 12-27 18:05:55.663 21467 21467 E AndroidRuntime: Caused by: java.lang.SecurityException: getDeviceId: Neither user 10117 nor current process has android.permission.READ_PHONE_STATE. 12-27 18:05:55.663 21467 21467 E AndroidRuntime: at android.os.Parcel.readException(Parcel.java:1683) 12-27 18:05:55.663 21467 21467 E AndroidRuntime: at android.os.Parcel.readException(Parcel.java:1636) 12-27 18:05:55.663 21467 21467 E AndroidRuntime: at com.android.internal.telephony.ITelephony$Stub$Proxy.getDeviceId(ITelephony.java:4281) |
3. SecurityException log 分析
SecurityException log 分析
4. SecurityException 解决方案
AndroidMainfest.xml 中申请权限
八、IllegalArgumentException: Service not registered 服务未注册异常
1.报错信息如下:
1 2 3 4 5 6 7 8 | 01-30 09:10:26.257 23681 23681 W System.err: java.lang.IllegalArgumentException: Service not registered: com.programandroid.Exception.ExceptionActivity$1@5f3161e 01-30 09:10:26.257 23681 23681 W System.err: at android.app.LoadedApk.forgetServiceDispatcher(LoadedApk.java:1363) 01-30 09:10:26.257 23681 23681 W System.err: at android.app.ContextImpl.unbindService(ContextImpl.java:1499) 01-30 09:10:26.257 23681 23681 W System.err: at android.content.ContextWrapper.unbindService(ContextWrapper.java:648) 01-30 09:10:26.257 23681 23681 W System.err: at com.programandroid.Exception.ExceptionActivity.ServiceNotRegisteredCrash(ExceptionActivity.java:276) 01-30 09:10:26.257 23681 23681 W System.err: at java.lang.reflect.Method.invoke(Native Method) 01-30 09:10:26.258 23681 23681 W System.err: at android.view.View$DeclaredOnClickListener.onClick(View.java:4744) 01-30 09:10:26.258 23681 23681 W System.err: at android.view.View.performClick(View.java:5675) |
2.Log分析如下:
Log 分析
此异常经常发生在错误的解除绑定服务造成的,解决方法:
1.解除绑定服务之前,先判断是否绑定过,只有绑定过后才可以解绑
2.使用
代码举例如下:
Service not registered 异常举例
九、BadTokenException 解决方案
1. log 举例
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | 03-12 14:55:13.734 5564 5564 E AndroidRuntime: FATAL EXCEPTION: main 03-12 14:55:13.734 5564 5564 E AndroidRuntime: Process: com.android.fmradio, PID: 5564 03-12 14:55:13.734 5564 5564 E AndroidRuntime: java.lang.RuntimeException: Error receiving broadcast Intent { act=android.intent.action.HEADSET_PLUG flg=0x40000010 (has extras) } in com.android.fmradio.FmService$FmServiceBroadcastReceiver@b3d2a03 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at android.app.LoadedApk$ReceiverDispatcher$Args.lambda$getRunnable$0(LoadedApk.java:1401) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at android.app.-$$Lambda$LoadedApk$ReceiverDispatcher$Args$_BumDX2UKsnxLVrE6UJsJZkotuA.run(Unknown Source:2) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at android.os.Handler.handleCallback(Handler.java:873) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:99) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at android.os.Looper.loop(Looper.java:193) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:6702) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:911) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: Caused by: android.view.WindowManager$BadTokenException: Unable to add window android.view.ViewRootImpl$W@f652dba -- permission denied for window type 2003 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at android.view.ViewRootImpl.setView(ViewRootImpl.java:851) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:356) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:93) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at android.app.Dialog.show(Dialog.java:329) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at com.android.fmradio.FmService$FmServiceBroadcastReceiver.onReceive(FmService.java:322) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: at android.app.LoadedApk$ReceiverDispatcher$Args.lambda$getRunnable$0(LoadedApk.java:1391) 03-12 14:55:13.734 5564 5564 E AndroidRuntime: ... 8 more |
2.产生原因
Android 8.0 之后如果要弹出系统弹窗,需要使用
3. 解决方案
系统弹窗,请用TYPE_APPLICATION_OVERLAY 替换之前的Windows Type。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | Dialog mFMDialog = new AlertDialog.Builder(context) .setTitle(R.string.airplane_title).setMessage(R.string.airplane_message) .setPositiveButton(R.string.close_FM, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { } } ).setCancelable(false).create(); // Android 8.0 之后弹出系统弹窗,需要使用 TYPE_APPLICATION_OVERLAY // <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" /> // 一下两个 之前常用的系统的Dialog 会报 // BadTokenException: Unable to add window android.view.ViewRootImpl$W@f652dba -- permission denied for window type 2003 //mFMDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_DIALOG); //mFMDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT); mFMDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY); mFMDialog.show(); |
4. 参考 Google Android GO 行为变更
Google 官方链接如下:
Android 8.0 Alert 弹窗行为变更
Android 8.0 Alert 弹窗行为变更
参考文章:
https://www.jianshu.com/p/8c6beaccfdb9;
https://blog.csdn.net/weixin_44053242/article/details/99293108;
https://mp.weixin.qq.com/s?__biz=MzU4MTIzMjM3MA==&mid=2247485503&idx=5&sn=6e9eb15516f43f06bb14f7438591e2ea&scene=21#wechat_redirect