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 blockLog.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;    }