1.数据持久化-SDCard

//数据持久化-SDCard
findViewById(R.id.button1).setOnClickListener(new OnClickListener()
{@Overridepublic void onClick(View v){//判断SDCard是否正常加载if(Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())){//获取SDCard根目录File sdcardPath = Environment.getExternalStorageDirectory();//获取SDCard可用空间long freeSpace = sdcardPath.getFreeSpace();Log.e("space", freeSpace + "");}}
});

2.SharedPreferences：(data/data/包名/shared_prefs/)

private void btn2Click(){// SharedPreferences sp = getPreferences(0);SharedPreferences sp = getSharedPreferences("filename", MODE_PRIVATE);//私有模式String str = sp.getString("value", "noread");boolean bol = sp.getBoolean("flag", true);textView.setText(str + " " + bol);}private void btn1Click(){
//        SharedPreferences sp = getPreferences(MODE_WORLD_READABLE | MODE_WORLD_WRITEABLE);//全局可读可写SharedPreferences sp = getSharedPreferences("filename", MODE_APPEND);//指定文件名，(内容)追加模式Editor editor = sp.edit();String value = editText.getText().toString();editor.putString("value", value);editor.putBoolean("flag", false);editor.commit();}

3.内部存储internalStorage:(data/data/包名/files/)

private void btn2Click(){try{FileInputStream fis = openFileInput("fos1.txt");//读取文件int length = 0;byte[] buffer = new byte[1024];while(-1 != (length = fis.read(buffer))){textView.setText(new String (buffer,0,length));}}catch (FileNotFoundException e){e.printStackTrace();}catch (IOException e){e.printStackTrace();}}private void btn1Click(){FileOutputStream fos = null;try{fos = openFileOutput("fos1.txt",MODE_PRIVATE);//写入文件String str = editText.getText().toString();fos.write(str.getBytes());fos.flush();}catch (FileNotFoundException e){e.printStackTrace();}catch (IOException e){e.printStackTrace();}finally{if( null != fos ){try{fos.close();}catch (IOException e){e.printStackTrace();}}}}