Always want to preview your camera in SurfaceView

As per the title, I would like to start the camera on SurfaceView as soon as the application is started, and I always want to keep previewing, but I use MediaRecorder to provide recording functionality.
It's been a little over two months since I first started Android, so I don't know anything about it, but as a feeling,
When using the Camera API or MediaRecorder API, I feel that it is not suitable.There are several things I would like to improve with the current code, so please help me to improve it.

What you want to improve
①I want to always display the camera image in SurfaceView from startup (even after recording)
②I want to get the image that the camera will get from the in-camera (sub-camera?)
③Implement auto-focus functionality and always do auto-focus

が and は have found several large samples depending on the Camera API, but I would like to improve them somehow.Thank you for your cooperation.

public class MainActivity extensions AppCompatActivity implements SurfaceHolder.Callback{

static MediaRecorder mRecorder;
static Camera;
static SurfaceHolder;
Button button 1;
TextView text1;
SurfaceView mSurfaceView1;
static boolean isRecording = false;
@ Override
protected void onCreate (Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mRecorder = new MediaRecorder();
    setContentView(R.layout.activity_main);
    initRecorder();
    mSurfaceView1=(SurfaceView) findViewById (R.id.surfaceView1);
    button1 = (Button) findViewById (R.id.button1);
    text1 = (TextView) findViewById (R.id.textView1);
    text1.setText("Now Standing By...");
    mHolder=mSurfaceView1.getHolder();

    mHolder.addCallback(this);

    button1.setOnClickListener(newView.OnClickListener(){
        @ Override
        public void onClick (View v) {
            if(isRecording){
                mRecorder.stop();
                isRecording = false;
                initRecorder();
                prepareRecorder();
                text1.setText("Stop Recording");
                button1.setText("Rec●");
            } else{
                text1.setText("Now Recording");
                isRecording = true;
                mRecorder.start();
                button1.setText("Stop Rec");
            }
        }
    });

}
public Camera getCameraInstance(){
    mCamera=null;
    try{
        mCamera=Camera.open(1);
    } catch(Exceptione){
        e.printStackTrace();
    }
    return mCamera;
}

private void initRecorder(){
    mRecorder.setAudioSource (MediaRecorder.AudioSource.CAMCORDER);
    mRecorder.setVideoSource (MediaRecorder.VideoSource.CAMERA);
    mRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
    mRecorder.setAudioEncoder (MediaRecorder.AudioEncoder.AAC);
    mRecorder.setVideoEncoder (MediaRecorder.VideoEncoder.H264);



          // recorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH));

    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    File pathExternalPublicDir=Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM+File.separator+"VID_"+timeStamp+".mp4");
    String dir=pathExternalPublicDir.getPath();

    mRecorder.setOutputFile(dir);
    mRecorder.setMaxDuration (60*1000);
    mRecorder.setMaxFileSize (50*1000*1000);
}

private void prepareRecorder(){
    mRecorder.setPreviewDisplay(mHolder.getSurface());

    try{
        mRecorder.prepare();
    }catch(IllegalStateExceptione){
        e.printStackTrace();
        finish();
    }catch(IOExceptione){
        e.printStackTrace();
        finish();
    }
}
@ Override
public void surfaceCreated (SurfaceHolder holder) {
    prepareRecorder();
    try{
        Camera.Parameters parameters=mCamera.getParameters();
        List<String>focusList=params.getSupportedFocusModes();
        for(inti=0;i<focusList.size();i++){
            Log.d("CameraFocusMode:", focusList.get(i));
        }
        param.setFocusMode(Camera.Parameters.FOCUS_MODE_INFINITY);
        mCamera.setParameters(params);
        mCamera.setPreviewDisplay(holder);
        mCamera.startPreview();
        mCamera.autoFocus(mAutoFocusListener);
    }catch(Exceptione) {e.printStackTrace();}
}
private Camera.AutoFocusCallback mAutoFocusListener=new Camera.AutoFocusCallback(){
    public void onAutoFocus(boolean success, Camera camera) {

        camera.takePicture(null, null, null);
    }
};

@ Override
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h){

}
@ Override
public void surfaceDestroyed (SurfaceHolder holder) {
    if(isRecording){
        mRecorder.stop();
        isRecording = false;
    }
    mRecorder.release();
    finish();
}

(Partial excerpt)

android java camera

2022-09-29 21:26