文件IO

    final String FILE_PATH="/data/data/com.android.hymake.ecard/";
    final String FILE_NAME="CARD.XML";
    final String TEXT_ENCODING = "UTF-8";

    File file;
    FileOutputStream out;
    FileInputStream in;
    String display;

    //生成保存本机名片的XML文件并显示内容
    private void generateLocalECardXml(){
    	try {
			String infoToWriter = getLocalECardInfo();
			out = this.openFileOutput(FILE_NAME, MODE_PRIVATE);
			out.write(infoToWriter.getBytes());
			Log.i(TAG, "filewrite:"+infoToWriter);
			out.close();
			Log.i(TAG, "create local ecard xml file successfully!");

			in = this.openFileInput(FILE_NAME);
			byte[] temp = new byte[1024];
			int length = in.read(temp);

			display = EncodingUtils.getString(temp, TEXT_ENCODING);
			Log.i(TAG, "fileread:"+display);
			in.close();
			Toast.makeText(Ecard.this, display, Toast.LENGTH_LONG).show();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			Log.e(TAG, e.getMessage());
		}
    }

    //读取本机名片并生成XML形式的实符串
    private String getLocalECardInfo() throws Exception{
    	StringBuffer xmlStr;
    	//获取名片表中第一条记录
    	mCardsCursor = mDbHelper.get(1, CardsDbAdapter.DATABASE_TB_CARDS);
    	if (mCardsCursor==null){
        	setListAdapter(null);
        	Log.e(TAG,"本机名片不在!");
        	throw new Exception("本机名片不在!");
    	}
    	xmlStr = new StringBuffer("<?xml version=\"1.0\" encoding=\"utf-8\"?><cardinfo>");
    	xmlStr.append("<username>").append(getNotNullStr(mCardsCursor.getString(1)))
    			.append("</username");
    	xmlStr.append("<phonenumber>").append(getNotNullStr(mCardsCursor.getString(3)))
				.append("</phonenumber>");
    	xmlStr.append("<useraddress>").append(getNotNullStr(mCardsCursor.getString(4)))
				.append("</useraddress>");
    	xmlStr.append("<usernote>").append(getNotNullStr(mCardsCursor.getString(5)))
				.append("</usernote>");
    	xmlStr.append("</cardinfo>");
    	return xmlStr.toString();
    }

    public static String getNotNullStr(String str){
    	return null==str?"":str;
    }