写文件

写入内部存储：

public Boolean SaveDataToRom(String name, String pwd){
        Boolean flag = false;
        try{
            String content = name+":"+pwd;
            FileOutputStream fos = context.openFileOutput("data.txt", Context.MODE_WORLD_WRITEABLE|Context.MODE_WORLD_READABLE);
            fos.write(content.getBytes());
            fos.flush();
            fos.close();
            flag = true;
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }finally{
            return flag;
        }
        
    }

 写入sdcard:

public Boolean SaveDataToSDCard(String name, String pwd){
        Boolean flag = false;
        try{
            String content = name+":"+pwd;
            if(Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())){
                FileOutputStream fos = new FileOutputStream(new File(Environment.getExternalStorageDirectory(),"test.txt"));
                fos.write(content.getBytes());
                fos.flush();
                fos.close();
                flag = true;
            }else{
                return flag;
            }
                
            
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }finally{
            return flag;
        }
        
    }