把assets的数据拷贝到手机 data/data/包名xxx下

private void copyDB(String path) {

// 判断只要拷贝一次就不要再拷贝

        try {

            InputStream is = getAssets().open(path);

            File file = new File(getFilesDir(), path);

            if(file.exists()&&file.length()>0){

                //正常 不需要拷贝 了

              Log.i("select","不需要拷贝");

            }else{

                FileOutputStream fos = new FileOutputStream(file);

                byte[] buffer = new byte[1024];

                int len = 0;

                while((len=is.read(buffer))!=-1){

                    fos.write(buffer,0,len);



                }

                is.close();

                fos.close();

            }



        } catch (IOException e) {

            e.printStackTrace();

        }

    }