在Android中实现文件读写

android 实现下载文件

/**

　　* 从网上下载

　　*@param url 下载路径

　　*@param outputFile 创建本地保存流的文件

　　*@return

　　* @return 下载失败返回1(比如没有网络等情况)下载成功返回0

　　*/

　　public static int downloadFile(String urlPsth, File outputFile) {

　　int result=0;

　　try {

　　URL url = new URL(urlPsth);

　　HttpURLConnection conn =(HttpURLConnection) url.openConnection();

　　conn.setDoInput(true);

　　conn.connect();

　　if( conn.getResponseCode() == HttpURLConnection.HTTP_OK)

　　{

　　InputStream is = conn.getInputStream();

　　FileOutputStream fos = new FileOutputStream(outputFile);

　　byte[] bt = new byte[1024];

　　int i = 0;

　　while ((i = is.read(bt)) > 0) {

　　fos.write(bt, 0, i);

　　}

　　fos.flush();

　　fos.close();

　　is.close();

　　}else {

　　result=1;

　　}

　　} catch (FileNotFoundException e) {

　　result=1;

　　} catch (IOException e) {

　　result=1;

　　}

　　return result;

　　}

编程中文件读写是少不了的，如下：

读：
public String ReadSettings(Context context){
      FileInputStream fIn = null;
      InputStreamReader isr = null;
     
      char[] inputBuffer = new char[255];
      String data = null;
     
      try{
       fIn = openFileInput("settings.dat");      
          isr = new InputStreamReader(fIn);
          isr.read(inputBuffer);
          data = new String(inputBuffer);
          Toast.makeText(context, "Settings read",Toast.LENGTH_SHORT).show();
          }
          catch (Exception e) {      
          e.printStackTrace();
          Toast.makeText(context, "Settings not read",Toast.LENGTH_SHORT).show();
          }
          finally {
             try {
                    isr.close();
                    fIn.close();
                    } catch (IOException e) {
                    e.printStackTrace();
                    }
          }
          return data;
     }

写：
    public void WriteSettings(Context context, String data){
      FileOutputStream fOut = null;
      OutputStreamWriter osw = null;
     
      try{
       fOut = openFileOutput("settings.dat",MODE_PRIVATE);      
          osw = new OutputStreamWriter(fOut);
          osw.write(data);
          osw.flush();
          Toast.makeText(context, "Settings saved",Toast.LENGTH_SHORT).show();
          }
          catch (Exception e) {      
          e.printStackTrace();
          Toast.makeText(context, "Settings not saved",Toast.LENGTH_SHORT).show();
          }
          finally {
             try {
                    osw.close();
                    fOut.close();
                    } catch (IOException e) {
                    e.printStackTrace();
                    }
          }
     }

使用方法：
WriteSettings(this,"setting0, setting1, setting2");
String data[] = ReadSettings(this).split(",");


在读取txt文件时，可能会遇到中文乱码情况，解决办法如下：

private String getTextString(String pathandname) throws IOException{
		
		String str="";
		
		FileInputStream fis = new FileInputStream(pathandname);
//		InputStreamReader isr=new InputStreamReader(fis, "gbk");
//		BufferedReader br=new BufferedReader(isr);
		
		int size=fis.available();
		
		byte[] buffer=new byte[size];
		
		fis.read(buffer);

		fis.close();
		   
		str = new String(buffer,"GBK");//支持双字节字符
		
		myApp.setCharNumofString(str.length());//存储总字符数
		
		return  str;
	}

读取assets文件夹下的txt文件
http://gundumw100.iteye.com/blog/850611