How to save a byte into mysql database in java android

Question

am trying to save to save a fingerprint image which is a byte into mysql database from my android app.

 public void save(View view) {

    String id = efid.getText().toString().trim();

    String left_finger_image = new String(Left_Finger_Image);
    String right_finger_image = new String(Right_Finger_Image);
    String left_finger_iso = new String(Left_Finger_ISOTemplate);
    String right_finger_iso = new String(Right_Finger_ISOTemplate);

    if(!id.equals("")){
        StringRequest stringRequest = new StringRequest(Request.Method.POST, URL_SAVE_FINGERPRINT, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                Log.d("res", response);
                if (response.equals("error")==false) {
                    Toast.makeText(Enrollment.this, "Fingerprint Enrolled Successfully..", Toast.LENGTH_SHORT).show();
                    Intent intent = new Intent(Enrollment.this, MainActivity.class);
                    startActivity(intent);
                    finish();
                } else if (response.equals("failure")==true) {
                    Toast.makeText(Enrollment.this, "Fingerprint Enrolled Failed..", Toast.LENGTH_SHORT).show();
                }
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Toast.makeText(Enrollment.this, error.toString().trim(), Toast.LENGTH_SHORT).show();
            }
        }){
            @Override
            protected Map<String, String> getParams() throws AuthFailureError {
                Map<String, String> data = new HashMap<>();
                data.put("fid", id);
                data.put("l_finger",left_finger_image);
                data.put("r_finger",right_finger_image);
                data.put("l_finger_iso",left_finger_iso);
                data.put("r_finger_iso",right_finger_iso);

                return data;

            }
        };
        RequestQueue requestQueue = Volley.newRequestQueue(getApplicationContext());
        requestQueue.add(stringRequest);
    }else{
        Toast.makeText(this, "Fields can not be empty!", Toast.LENGTH_SHORT).show();
    }
}