将图像存储在数据库中并检索以回显为json

Question

I know this question have been asked many times but I am really having a problem understanding what is happening

I have a project to make an android app that uses the same database as a website my partner is working on

and my problem is working with images

I know that we should not store images in the database....but we have too here

the images are getting stored in the data base as blob and it's working fine on the website but not on my app

I loaded to the app some of the images uploaded to database from the website and some that I have uploaded using the interface of sql wamp server

and they work fine

but when I upload an image from my app to the database when I fetch it back it doesn't show up at all

here is what I'm doing

I start an intent to pick an image with this code

Intent intent = new Intent();
            intent.setType("image/*");
            intent.setAction(Intent.ACTION_GET_CONTENT);
            startActivityForResult(Intent.createChooser(intent,"Select Picture"), 1);

and ononActivityResult

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (resultCode == RESULT_OK) {
        if (requestCode == 1) {
            Uri selectedImageUri = data.getData();
            try {
                PickedImage= MediaStore.Images.Media.getBitmap(this.getContentResolver(), selectedImageUri);

                nPostImage.setImageBitmap(PickedImage);

                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                PickedImage.compress(Bitmap.CompressFormat.PNG, 100, baos);
                nPostImageBytes = baos.toByteArray();

            } catch (IOException e) {
                Toast.makeText(this,"Error Selecting Picture",Toast.LENGTH_SHORT).show();
                e.printStackTrace();
            }
        }// if picking a picture
    }//if ok
}//On activity get result

and then I call this method that uploads the data to the database using volley

private void AddPost(final String UserID, final String UserType, final String nText, final byte[] nImage)
{
    final ProgressDialog loading=ProgressDialog.show(this,"please wait...","adding",false,false);

    String url="http://192.168.43.178/studentpool/add_post.php";

    StringRequest stringRequest=new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            loading.dismiss();
            try {
                JSONObject jsonObject=new JSONObject(response);
                if(jsonObject.getInt(LoginActivity.TAG_SUCCESS)==1)
                {
                    loading.dismiss();
                    Toast.makeText(AddPostActivity.this,"Added Successfully",Toast.LENGTH_SHORT).show();

                    Intent intent=new Intent(AddPostActivity.this,MainActivity.class);
                    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    startActivity(intent);
                }
                else
                {
                    loading.dismiss();
                    Toast.makeText(AddPostActivity.this,jsonObject.getString("message"),Toast.LENGTH_SHORT).show();
                }
            } catch (JSONException e) {
                e.printStackTrace();
                Toast.makeText(AddPostActivity.this,"Error adding",Toast.LENGTH_SHORT).show();
            }
        }
    }, new Response.ErrorListener(){
        @Override
        public void onErrorResponse(VolleyError error) {
            error.printStackTrace();
        }
    }) {
        @Override
        protected Map<String, String> getParams() throws AuthFailureError {
            Map<String, String> params = new HashMap<>();
            params.put("id",UserID);
            params.put("type",UserType);
            params.put("text",nText);
            params.put("image",Base64.encodeToString(nImage,Base64.DEFAULT));

            return params;
        }
    };

    RequestQueue requestQueue = Volley.newRequestQueue(this);
    requestQueue.add(stringRequest);
}//AddPost}

and this is my php code

<?php if($_SERVER['REQUEST_METHOD']=='POST'){
$id  = $_POST['id'];
$text= $_POST['text'];
$image=$_POST['image'];
$type=$_POST['type'];

require_once __DIR__ . '/db_config.php';

$con = mysqli_connect(DB_SERVER,DB_USER,DB_PASSWORD,DB_DATABASE);

$dt = new DateTime();
$dt->add(new DateInterval('PT3H'));

$result=mysqli_query($con,"INSERT INTO posts(user_id,text,post_image,date,type) VALUES ('$id','$text','$image','".$dt->format('Y-m-d h:i:s')."','$type')");

if ($result)
{

//success
$response["success"] = 1;

echo json_encode($response);

}
else
{
    $response["success"] = 0;
    $response["message"] = "Error adding the post";

    echo json_encode($response);
}}else{
$response["success"] = 0;
$response["message"] = "Missing required data";

// echo no users JSON
echo json_encode($response); }//no data ?>

I tried changing the post_image type to mediumtext to see what is getting stored in the database

and the images that works fine (the ones uploaded from the interface) have this kind of format

ÿØÿà?JFIFÿÛC...

the one uploaded from the app has this format

/9j/4AAQSkZJRgABAQAAAQABAAD/2wBD..

I tried encoding the image before storing it in the database but I got an JSONexception

please help if you know anything about this

and sorry for the long question...

Thanks for your time

Answer 1

I think if you add "data:image/png;base64," before your Base64 string, your problem might be solved. So try this:

params.put("image", "data:image/png;base64," + Base64.encodeToString(nImage,Base64.DEFAULT));