怎么在Android中利用orc实现一个文字识别功能

public class MainActivity extends AppCompatActivity implements View.OnClickListener {private TextView mTvInfo;private TessBaseAPI mBaseAPI;private ProgressBar mProbar;private String path;private RadioGroup mRadioGroup;private RadioButton mRbtnIdCard;private RadioButton mRbtnBankNumber;private RadioButton mRbtnTxt;@Overrideprotected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);  findViewById(R.id.btn_start).setOnClickListener(this);  mProbar = (ProgressBar) findViewById(R.id.pb);  mTvInfo = (TextView) findViewById(R.id.tv_info);  mRadioGroup = (RadioGroup) findViewById(R.id.rg);  mRbtnIdCard = (RadioButton) findViewById(R.id.rb_idCard);  mRbtnBankNumber = (RadioButton) findViewById(R.id.rb_bankNumber);  mRbtnTxt = (RadioButton) findViewById(R.id.rb_txt);  mRadioGroup.check(0);  path = Environment.getExternalStorageDirectory().getAbsoluteFile().getAbsolutePath();}@Overridepublic void onClick(View v) {  mTvInfo.setText("");  switch (v.getId()) {    case R.id.btn_start:      if (Build.VERSION.SDK_INT >= 23) {        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {          // 没有权限          if(ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.CALL_PHONE)){            //如果没勾选“不再询问”，向用户发起权限请求            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CALL_PHONE}, 0);          }else{            Toast.makeText(this,"请前往设置——>存储卡权限——>允许",Toast.LENGTH_SHORT).show();          }        } else {          // 有权限,接着你要干的活          startReadText();        }      }else{        startReadText();      }      break;  }}private Handler mHandler = new Handler() {  @Override  public void handleMessage(Message msg) {    switch (msg.what) {      case 0:        String s = (String) msg.obj;        if (!TextUtils.isEmpty(s)) {          mProbar.setVisibility(View.GONE);          mTvInfo.setText(s);          //释放bitmap          mBaseAPI.clear();        } else {          mProbar.setVisibility(View.GONE);          Toast.makeText(MainActivity.this, "识别图片内容失败", Toast.LENGTH_SHORT).show();        }        break;      case 1:        Toast.makeText(MainActivity.this, "读取图片失败", Toast.LENGTH_SHORT).show();        break;    }  }};private Bitmap getBitmap(int id) {  Bitmap bitmap = null;  try {    bitmap = BitmapFactory.decodeResource(getResources(), id);  } catch (Exception e) {    return null;  }  return bitmap;}private void startReadText() {  File f = new File(path+"/tessdata") ;  if(!f.exists()){    Toast.makeText(this,"请先下载好语言包置于sd/tessdata目录",Toast.LENGTH_SHORT).show();    return;  }  final int btnId = mRadioGroup.getCheckedRadioButtonId();  final int resId ;  if(R.id.rb_idCard==btnId){    resId = R.drawable.idcard;  }else if(R.id.rb_bankNumber==btnId){    resId = R.drawable.bank_number;  }else{    resId = R.drawable.tet_info;  }  mProbar.setVisibility(View.VISIBLE);  new Thread() {    @Override    public void run() {      mBaseAPI = new TessBaseAPI();//初始化需要耗时，可以启动时程序时，预初始化      mBaseAPI.init(path + File.separator, "chi_sim");      Bitmap bitmap = getBitmap(resId);      if (bitmap == null) {        mHandler.sendEmptyMessage(1);      } else {        mBaseAPI.setImage(bitmap);        //根据Init的语言，获得ocr后的字符串        String t = mBaseAPI.getUTF8Text();//耗时操作        Message obtain = Message.obtain();        obtain.what = 0;        obtain.obj = t;        mHandler.sendMessage(obtain);      }    }  }.start();}}