Android 如何打印异常的stacktrace
我想打印堆栈跟踪,因为目前我正在运行这个Android 如何打印异常的stacktrace,android,android-logcat,Android,Android Logcat,我想打印堆栈跟踪,因为目前我正在运行这个 } catch (IOException e) { throw new Error("Copying Failed"); } 我被告知打印e.stacktrace() 如何执行此操作?很可能是您被要求通过e.printStackTrace()打印堆栈跟踪 } catch (IOException e) { e.printStackTrace(); } } catch (IOException e) { e.printStack
} catch (IOException e) {
throw new Error("Copying Failed");
}
我被告知打印e.stacktrace()代码>
如何执行此操作?很可能是您被要求通过e.printStackTrace()打印堆栈跟踪代码>
} catch (IOException e) {
e.printStackTrace();
}
} catch (IOException e) {
e.printStackTrace();
throw new Error("Copying Failed");
}
并检查LogCat的输出。在Android中,您应该使用与Android使用的LogCat日志查看器配合良好的日志方法
} catch (IOException e) {
Log.e("YOUR ERROR TAG HERE", "Copying failed", e);
}
使用以throwable作为参数的Log.e方法,可以确保Log类将获取stacktrace并将其正确记录到Logcat。如果您使用e.printStackTrace,这将使用常规Java日志记录方法,它将不会在Logcat中正确显示,在某些情况下,无法双击Logcat中的类名跳转到stacktrace中提到的类和方法中
被零除的打印堆栈跟踪将如下所示:
11-21 20:55:47.360: W/System.err(989): java.lang.ArithmeticException: divide by zero
11-21 20:55:47.379: W/System.err(989): at test.tabs.TabChooser.onCreate(TabChooser.java:15)
11-21 20:55:47.390: W/System.err(989): at android.app.Activity.performCreate(Activity.java:4465)
11-21 20:55:47.410: W/System.err(989): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
11-21 20:55:47.410: W/System.err(989): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1919)
11-21 20:55:47.420: W/System.err(989): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1980)
11-21 20:55:47.420: W/System.err(989): at android.app.ActivityThread.access$600(ActivityThread.java:122)
11-21 20:55:47.420: W/System.err(989): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1146)
11-21 20:55:47.420: W/System.err(989): at android.os.Handler.dispatchMessage(Handler.java:99)
11-21 20:55:47.420: W/System.err(989): at android.os.Looper.loop(Looper.java:137)
11-21 20:55:47.420: W/System.err(989): at android.app.ActivityThread.main(ActivityThread.java:4340)
11-21 20:55:47.430: W/System.err(989): at java.lang.reflect.Method.invokeNative(Native Method)
11-21 20:55:47.430: W/System.err(989): at java.lang.reflect.Method.invoke(Method.java:511)
11-21 20:55:47.430: W/System.err(989): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
11-21 20:55:47.430: W/System.err(989): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
11-21 20:55:47.430: W/System.err(989): at dalvik.system.NativeStart.main(Native Method)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): Copying failed
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): java.lang.ArithmeticException: divide by zero
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at test.tabs.TabChooser.onCreate(TabChooser.java:16)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.app.Activity.performCreate(Activity.java:4465)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1919)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1980)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.app.ActivityThread.access$600(ActivityThread.java:122)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1146)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.os.Handler.dispatchMessage(Handler.java:99)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.os.Looper.loop(Looper.java:137)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.app.ActivityThread.main(ActivityThread.java:4340)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at java.lang.reflect.Method.invokeNative(Native Method)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at java.lang.reflect.Method.invoke(Method.java:511)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at dalvik.system.NativeStart.main(Native Method)
异常被记录为警告,日志标记没有多大帮助
被零除的正确日志记录如下所示:
11-21 20:55:47.360: W/System.err(989): java.lang.ArithmeticException: divide by zero
11-21 20:55:47.379: W/System.err(989): at test.tabs.TabChooser.onCreate(TabChooser.java:15)
11-21 20:55:47.390: W/System.err(989): at android.app.Activity.performCreate(Activity.java:4465)
11-21 20:55:47.410: W/System.err(989): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
11-21 20:55:47.410: W/System.err(989): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1919)
11-21 20:55:47.420: W/System.err(989): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1980)
11-21 20:55:47.420: W/System.err(989): at android.app.ActivityThread.access$600(ActivityThread.java:122)
11-21 20:55:47.420: W/System.err(989): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1146)
11-21 20:55:47.420: W/System.err(989): at android.os.Handler.dispatchMessage(Handler.java:99)
11-21 20:55:47.420: W/System.err(989): at android.os.Looper.loop(Looper.java:137)
11-21 20:55:47.420: W/System.err(989): at android.app.ActivityThread.main(ActivityThread.java:4340)
11-21 20:55:47.430: W/System.err(989): at java.lang.reflect.Method.invokeNative(Native Method)
11-21 20:55:47.430: W/System.err(989): at java.lang.reflect.Method.invoke(Method.java:511)
11-21 20:55:47.430: W/System.err(989): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
11-21 20:55:47.430: W/System.err(989): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
11-21 20:55:47.430: W/System.err(989): at dalvik.system.NativeStart.main(Native Method)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): Copying failed
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): java.lang.ArithmeticException: divide by zero
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at test.tabs.TabChooser.onCreate(TabChooser.java:16)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.app.Activity.performCreate(Activity.java:4465)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1919)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1980)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.app.ActivityThread.access$600(ActivityThread.java:122)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1146)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.os.Handler.dispatchMessage(Handler.java:99)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.os.Looper.loop(Looper.java:137)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at android.app.ActivityThread.main(ActivityThread.java:4340)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at java.lang.reflect.Method.invokeNative(Native Method)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at java.lang.reflect.Method.invoke(Method.java:511)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
11-21 21:03:32.480: E/YOUR ERROR TAG HERE(1356): at dalvik.system.NativeStart.main(Native Method)
将异常作为错误正确记录在日志标记和日志消息中。另一种方法非常有用:
try
{
...
}
catch (Exception e)
{
Log.e(APP_TAG, "STACKTRACE");
Log.e(APP_TAG, Log.getStackTraceString(e));
}
这比系统更可取吗?呃?@Igor G:是的,Igor,这比系统更可取。如果您仅使用System.err,那么您将无法在LogCat输出中看到您的应用程序标记。我只得到java.lang.NullPointerException
,但这不是堆栈跟踪,这只是错误!,我怎样才能得到完整的跟踪?@FranciscoCorralesMorales:你把三个参数传递给Log.e了吗?如果只传递两个参数,例如Log.e(“tag”,e)代码>或Log.e(“标记”、“消息”+e)代码>那么您将无法获得跟踪。必须是Log.e(“标签”,“消息”,e)代码>。不知何故,从未知道存在这种对日志方法的重写。呜呜!您在哪里设置了应用程序标签?还是你没有?@FranciscoCorralesMorales:APP\u TAG
只是用常量变量命名项目标记的常用约定。您可以将其定义为您想要的应用程序标记名。