android - 需要处理未捕获的异常并发送日志文件

Question

当我的应用程序创建一个未处理的异常，而不是简单地终止时，我想首先让用户有机会发送一个日志文件。我意识到在遇到随机异常后做更多的工作是有风险的，但是，嘿，最糟糕的是应用程序完成崩溃并且没有发送日志文件。事实证明这比我预期的要棘手:)

工作原理:(1) 捕获未捕获的异常，(2) 提取日志信息并写入文件。

什么还不起作用:(3)开始一个 Activity 来发送电子邮件。最终，我将进行另一项 Activity 来征求用户的许可。如果我让电子邮件 Activity 正常工作，我预计对方不会有太多麻烦。

问题的症结在于我的 Application 类中捕获了未处理的异常。由于那不是 Activity，因此如何使用 Intent.ACTION_SEND 启动 Activity 并不明显。也就是说，通常要启动一项 Activity ，需要调用 startActivity 并使用 onActivityResult 恢复。 Activity 支持这些方法，但 Application 不支持。

关于如何做到这一点的任何建议？

以下是一些代码 fragment 作为入门指南:

public class MyApplication extends Application
{
  defaultUncaughtHandler = Thread.getDefaultUncaughtExceptionHandler();
  public void onCreate ()
  {
    Thread.setDefaultUncaughtExceptionHandler (new Thread.UncaughtExceptionHandler()
    {
      @Override
      public void uncaughtException (Thread thread, Throwable e)
      {
        handleUncaughtException (thread, e);
      }
    });
  }

  private void handleUncaughtException (Thread thread, Throwable e)
  {
    String fullFileName = extractLogToFile(); // code not shown

    // The following shows what I'd like, though it won't work like this.
    Intent intent = new Intent (Intent.ACTION_SEND);
    intent.setType ("plain/text");
    intent.putExtra (Intent.EXTRA_EMAIL, new String[] {"me@mydomain.example"});
    intent.putExtra (Intent.EXTRA_SUBJECT, "log file");
    intent.putExtra (Intent.EXTRA_STREAM, Uri.parse ("file://" + fullFileName));
    startActivityForResult (intent, ACTIVITY_REQUEST_SEND_LOG);
  }

  public void onActivityResult (int requestCode, int resultCode, Intent data)
  {
    if (requestCode == ACTIVITY_REQUEST_SEND_LOG)
      System.exit(1);
  }
}

Answer 1

这是完整的解决方案(几乎是:我省略了 UI 布局和按钮处理) - 源自大量实验以及其他与此过程中出现的问题相关的各种帖子。

你需要做很多事情:

1. 在您的 Application 子类中处理 uncaughtException。
2. 捕获异常后，启动一个新的 Activity 来要求用户发送日志。
3. 从 logcat 的文件中提取日志信息并写入您的自己的文件。
4. 启动一个电子邮件应用，将您的文件作为附件提供。
5. list :过滤您的 Activity 以被您的异常处理程序识别。
6. (可选)设置 Proguard 以去除 Log.d() 和 Log.v()。

现在，这里是详细信息:

(1 & 2) 处理 uncaughtException，开始发送日志 Activity :

public class MyApplication extends Application
{
  public void onCreate ()
  {
    // Setup handler for uncaught exceptions.
    Thread.setDefaultUncaughtExceptionHandler (new Thread.UncaughtExceptionHandler()
    {
      @Override
      public void uncaughtException (Thread thread, Throwable e)
      {
        handleUncaughtException (thread, e);
      }
    });
  }

  public void handleUncaughtException (Thread thread, Throwable e)
  {
    e.printStackTrace(); // not all Android versions will print the stack trace automatically

    Intent intent = new Intent ();
    intent.setAction ("com.mydomain.SEND_LOG"); // see step 5.
    intent.setFlags (Intent.FLAG_ACTIVITY_NEW_TASK); // required when starting from Application
    startActivity (intent);

    System.exit(1); // kill off the crashed app
  }
}

(3) 提取日志(我把它放在我的 SendLog Activity 中):

private String extractLogToFile()
{
  PackageManager manager = this.getPackageManager();
  PackageInfo info = null;
  try {
    info = manager.getPackageInfo (this.getPackageName(), 0);
  } catch (NameNotFoundException e2) {
  }
  String model = Build.MODEL;
  if (!model.startsWith(Build.MANUFACTURER))
    model = Build.MANUFACTURER + " " + model;

  // Make file name - file must be saved to external storage or it wont be readable by
  // the email app.
  String path = Environment.getExternalStorageDirectory() + "/" + "MyApp/";
  String fullName = path + <some name>;

  // Extract to file.
  File file = new File (fullName);
  InputStreamReader reader = null;
  FileWriter writer = null;
  try
  {
    // For Android 4.0 and earlier, you will get all app's log output, so filter it to
    // mostly limit it to your app's output.  In later versions, the filtering isn't needed.
    String cmd = (Build.VERSION.SDK_INT <= Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1) ?
                  "logcat -d -v time MyApp:v dalvikvm:v System.err:v *:s" :
                  "logcat -d -v time";

    // get input stream
    Process process = Runtime.getRuntime().exec(cmd);
    reader = new InputStreamReader (process.getInputStream());

    // write output stream
    writer = new FileWriter (file);
    writer.write ("Android version: " +  Build.VERSION.SDK_INT + "\n");
    writer.write ("Device: " + model + "\n");
    writer.write ("App version: " + (info == null ? "(null)" : info.versionCode) + "\n");

    char[] buffer = new char[10000];
    do
    {
      int n = reader.read (buffer, 0, buffer.length);
      if (n == -1)
        break;
      writer.write (buffer, 0, n);
    } while (true);

    reader.close();
    writer.close();
  }
  catch (IOException e)
  {
    if (writer != null)
      try {
        writer.close();
      } catch (IOException e1) {
      }
    if (reader != null)
      try {
        reader.close();
      } catch (IOException e1) {
      }

    // You might want to write a failure message to the log here.
    return null;
  }

  return fullName;
}

(4) 启动一个电子邮件应用程序(也在我的 SendLog Activity 中):

private void sendLogFile ()
{
  String fullName = extractLogToFile();
  if (fullName == null)
    return;

  Intent intent = new Intent (Intent.ACTION_SEND);
  intent.setType ("plain/text");
  intent.putExtra (Intent.EXTRA_EMAIL, new String[] {"log@mydomain.example"});
  intent.putExtra (Intent.EXTRA_SUBJECT, "MyApp log file");
  intent.putExtra (Intent.EXTRA_STREAM, Uri.parse ("file://" + fullName));
  intent.putExtra (Intent.EXTRA_TEXT, "Log file attached."); // do this so some email clients don't complain about empty body.
  startActivity (intent);
}

(3 & 4) 这是 SendLog 的样子(不过，您必须添加 UI):

public class SendLog extends Activity implements OnClickListener
{
  @Override
  public void onCreate(Bundle savedInstanceState)
  {
    super.onCreate(savedInstanceState);
    requestWindowFeature (Window.FEATURE_NO_TITLE); // make a dialog without a titlebar
    setFinishOnTouchOutside (false); // prevent users from dismissing the dialog by tapping outside
    setContentView (R.layout.send_log);
  }

  @Override
  public void onClick (View v)
  {
    // respond to button clicks in your UI
  }

  private void sendLogFile ()
  {
    // method as shown above
  }

  private String extractLogToFile()
  {
    // method as shown above
  }
}

(5) list :

<manifest xmlns:android="http://schemas.android.com/apk/res/android" ... >
    <!-- needed for Android 4.0.x and eariler -->
    <uses-permission android:name="android.permission.READ_LOGS" />

    <application ... >
        <activity
            android:name="com.mydomain.SendLog"
            android:theme="@android:style/Theme.Dialog"
            android:textAppearance="@android:style/TextAppearance.Large"
            android:windowSoftInputMode="stateHidden">
            <intent-filter>
              <action android:name="com.mydomain.SEND_LOG" />
              <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
     </application>
</manifest>

(6) 设置 Proguard:

在 project.properties 中，更改配置行。您必须指定“优化”，否则 Proguard 不会删除 Log.v() 和 Log.d() 调用。

proguard.config=${sdk.dir}/tools/proguard/proguard-android-optimize.txt:proguard-project.txt

在 proguard-project.txt 中，添加以下内容。这告诉 Proguard 假设 Log.v 和 Log.d 没有副作用(即使它们在写入日志时有副作用)，因此可以在优化期间删除:

-assumenosideeffects class android.util.Log {
    public static int v(...);
    public static int d(...);
}

就是这样!如果您对此有任何改进建议，请告诉我，我可能会对此进行更新。