保存android程序崩溃日志到SD卡

	private boolean writeToSDCard(Throwable ex)
	{
		boolean isDealing = false;
		if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
		{
			RandomAccessFile randomAccessFile = null;
			try
			{
				String fileName = SDCARDROOT + File.separator + "logs" + File.separator + "crash" + File.separator;
				File file = new File(fileName);
				if(!file.exists())
					file.mkdirs();
				randomAccessFile = new RandomAccessFile(fileName + paserTime(System.currentTimeMillis())+ ".log", "rw");
				long fileLength = randomAccessFile.length();
				randomAccessFile.seek(fileLength);
				randomAccessFile.writeBytes(getThrowableInfo(ex));
			}
			catch (IOException e)
			{
				e.printStackTrace();
			}
			finally
			{
				if (randomAccessFile != null)
				{
					try
					{
						randomAccessFile.close();
						isDealing = true;
					}
					catch (IOException e)
					{
						e.printStackTrace();
					}
				}
			}
		}
		return isDealing;
	}

	private static String getThrowableInfo(Throwable ex)
	{
		StringWriter stringWriter = new StringWriter();
		PrintWriter printWriter = new PrintWriter(stringWriter);
		ex.printStackTrace(printWriter);
		return stringWriter.toString();
	}