AndroidのLogDog

Androidプログラムを書くとき、シミュレータやデバッガでは捉えられないexceptionによく遭遇します.時には自分できちんとプログラムを実行して他の機械に問題が発生することがあります.Google Playにはエラースタックアップロード機能がありますが、実行中のプロセス全体を記録することはできません.そのため、この問題を解決しようとするLogDogクラスを書きました.

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.lang.Thread.UncaughtExceptionHandler;
import java.sql.Date;
import java.text.SimpleDateFormat;
import java.util.HashSet;

import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Build;
import android.os.Environment;
import android.os.Looper;
//import android.util.Log;
import android.util.Log;

public class LogDog implements UncaughtExceptionHandler {
	
	public static String 			TAG = "LogDog";
	
	private static HashSet	_tags = new HashSet();
	private static boolean			_debug = false;
	
	static {
		// add tags to be captured
		_tags.add(PDFMaster.TAG);
		_tags.add(RecentlyUsedActivity.TAG);
		_tags.add(DB.TAG);
	}

	public static LogDog instance() {
		return _instance;
	}
	
	public static void i(String tag, String message) {
		if(_debug) {
			Log.i(tag, message);
			return;
		}
		PrintWriter writer = _instance.getWriter();
		if(writer != null && _tags.contains(tag)) {
			_instance._writer.println("i:" + tag + ":" + message);
		}
	}

	public static void e(String tag, String message) {
		if(_debug) {
			Log.i(tag, message);
			return;
		}
		PrintWriter writer = _instance.getWriter();
		if(writer != null && _tags.contains(tag)) {
			_instance._writer.println("e" + tag + ":" + message);
		}
	}

	public static void w(String tag, String message) {
		if(_debug) {
			Log.i(tag, message);
			return;
		}
		PrintWriter writer = _instance.getWriter();
		if(writer != null && _tags.contains(tag)) {
			_instance._writer.println("w" + tag + ":" + message);
		}
	}

	public void init(Context context) {
		_context = context;
		_fileName = _context.getString(R.string.app_name) + ".log";
		_defaultHandler = Thread.getDefaultUncaughtExceptionHandler();
		Thread.setDefaultUncaughtExceptionHandler(this);
	}
	
	public void close() {
		if(_writer != null) {
			_writer.close();
			_writer = null;
		}
	}
	
	// private
	
	private static LogDog					_instance = new LogDog();
	private static final String 			PATH =
		Environment.getExternalStorageDirectory().getPath() + "/log";
	private Context							_context;
	private String							_fileName;
	private Thread.UncaughtExceptionHandler	_defaultHandler;
	private PrintWriter						_writer = null;
	
	private LogDog() {
	}
	
	private PrintWriter getWriter() {
		if(_writer != null)
			return _writer;
		// check if we have SD card
		if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
			//Log.w(TAG, "sdcard unmounted,skip dump exception");
			return null;
		}
		File dir = new File(PATH);
		if (!dir.exists()) {
			dir.mkdirs();
		}
		File file = new File(PATH + "/" + _fileName);
		try {
			_writer = new PrintWriter(new BufferedWriter(new FileWriter(file)));
		} catch (IOException e) {
			//Log.e(TAG, "Failed to open " + PATH + "/" + FILE_NAME);
			_writer = null;
		}
		return _writer;
	}

	@Override
	public void uncaughtException(Thread thread, Throwable ex) {
		// first display a toast message
		new Thread() {
			@Override
			public void run() {
				Looper.prepare();
				PDFMarkerApp.instance().showToast("Sorry for the trouble, dumping uncaught exeption to SD card");
			}
		}.start();
		try {
			dump(ex);
		} catch (Exception e) {
			//Log.e(TAG, "Failed to dump because " + e.getMessage());
			e.printStackTrace();
		}
		if (_defaultHandler != null) {  
			_defaultHandler.uncaughtException(thread, ex);  
		} else {
			// sleep so the toast can have time to display
			try {
				Thread.sleep(3000);
			} catch (InterruptedException e) {
			}
			android.os.Process.killProcess(android.os.Process.myPid());  
		}
	}
	
	private void dump(Throwable ex) throws IOException, NameNotFoundException {
		PrintWriter writer = _instance.getWriter();
		if(writer == null)
			return;
		long current = System.currentTimeMillis();
		String time = new SimpleDateFormat("yyyyMMdd.HHmmss").format(new Date(current));
		_writer.println(time);
		PackageManager pm = _context.getPackageManager();
		PackageInfo pi = pm.getPackageInfo(_context.getPackageName(), PackageManager.GET_ACTIVITIES);
		_writer.print("App Version: ");
		_writer.print(pi.versionName);
		_writer.print('_');
		_writer.println(pi.versionCode);  
		_writer.print("OS Version: ");
		_writer.print(Build.VERSION.RELEASE);
		_writer.print("_");
		_writer.println(Build.VERSION.SDK_INT);
		_writer.print("Vendor: ");
		_writer.println(Build.MANUFACTURER);
		_writer.print("Model: ");
		_writer.println(Build.MODEL);
		_writer.print("CPU ABI: ");
		_writer.println(Build.CPU_ABI);
		_writer.println();
		ex.printStackTrace(_writer);
		close();
		File file = new File(PATH + "/" + _fileName);
		File file2 = new File(PATH + "/" + _fileName + "." + time + ".txt");
		file.renameTo(file2);
	}
	
}

使用時にすべてのログが最後の例外まで1つのファイルに記録されます.例外のたびに1つのファイルに単独で記録され、必要なすべての情報が関連付けられます.正常に動作している場合は、このファイルは次回上書きされ、スペースの問題は発生しません.デバッグするなら_debugを変更すると、すべてのログがLogCatに表示され、とても便利です.