日志记录程序是为了方便各种异常情况，为了方便日后的维修方案进行维修，程序无法百分百健康，完美，有必要保存在日志中代码。易于维护。Java了一个接口UncaughtExceptionHandler，Thread.setDefaultUncaughtExceptionHandler(handler)设置当线程因为未捕获到异常而突然终止，而且没有为该线程定义其它处理程序时所调用的默认处理程序。

所以我们能够继承UncaughtExceptionHandler。 在handler实现对日志的读写

   public class CrashHandler implements UncaughtExceptionHandler {

	// 系统默认的UncaughtException处理

	private Thread.UncaughtExceptionHandler mDefaultHandler;

	public CrashHandler() {

		mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();

	}

	@Override

	public void uncaughtException(Thread thread, Throwable ex) {

		try {

			// 创建日志文件

			File file = createCreashLogFile();

			// 写入日志文件

			if (file != null && file.exists()) {

				writeLog(file, ex);

			}

		} catch (Exception e) {

		    LogUtils.w("", e);

		}

		// 将异常抛给系统处�?

mDefaultHandler.uncaughtException(thread, ex);

	}

	private void writeLog(File logFile, Throwable ex) {

		PrintStream printStream = null;

		FileOutputStream fos = null;

		// 写入日志文件

		try {

			fos = new FileOutputStream(logFile);

			printStream = new PrintStream(fos);

			ex.printStackTrace(printStream);

		} catch (Exception e) {

		    LogUtils.w("", e);

		} finally {

			closeQuietly(printStream);

			closeQuietly(fos);

		}

	}

	private void closeQuietly(OutputStream os) {

		if (os != null) {

			try {

				os.close();

			} catch (IOException e) {

			    LogUtils.w("", e);

			}

		}

	}

	/** 创建�?个空白的崩溃日志文件 */

	public static File createCreashLogFile() throws IOException {

		if (!isExternalStorageAvaliable()) { // �?

查存储是否可�?

			return null;

		}

		File directory = new File(Environment.getExternalStorageDirectory()

				+ "/ViolationQuery/crash_log");

		if (!directory.exists()) {

			directory.mkdirs();

		}

		File file = new File(directory, createCrashLogFileName());

		if (file.exists()) {

			file.delete();

		}

		file.createNewFile();

		return file;

	}

	/** 存储是否可用 */

	public static boolean isExternalStorageAvaliable() {

		String state = Environment.getExternalStorageState();

		if (Environment.MEDIA_MOUNTED.equals(state)) {

			return true;

		} else {

			return false;

		}

	}

	private static String createCrashLogFileName() {

		String dateString = new SimpleDateFormat("yyyyMMdd_HHmmss",

				Locale.getDefault()).format(new Date());

		return "CrashLog_" + dateString + ".txt";

	}

}

<pre name="code" class="java">public class CrashManager {

	public static void start() {

		// 设置异常处理实例

		CrashHandler handler = new CrashHandler();

		Thread.setDefaultUncaughtExceptionHandler(handler);

	}

}

 然后在Application中调用Application中CrashManager.start();这样就大功告成了