尝试上传时，Android Studio会破坏Base64字符串

Question

So I am testing methods to upload an image to a php server. One of the methods was to convert the image to a Base64 String and upload it and then decode it when needed.

When I uploaded a picture I noticed that there was a difference in the Strings. Some spaces were missing and some next lines were misplaced.

Before I sent the string to the server the string is okay and then it goes through a _POST command in the php file and then it is inserted into the database using INSERT INTO.

I suspect that the header that I use changes the string when I try to upload it. the header is /x-www-form-urlencoded. I tried using /json but if the json object is converted to string it changes the original string. So what header do I need to use so the string won't change? Or is there another method to upload a picture to a MySQL database?

This is the method I use to upload the string to the server:

ImageString = getStringImage(bitmap); 
String ImageUploadString="image="+ImageString; 
final OkHttpClient client = new OkHttpClient(); 
MediaType contentType = MediaType.parse("application/x-www-form-urlencoded; charset=utf-8"); 

RequestBody body = RequestBody.create(contentType, imageUploadString)); 
Request request = new Request.Builder().url(uploadURL).post(body).build(); 
Response response = null; 
try { 
    response = client.newCall(request).execute(); 
} catch (IOException e) { 
    e.printStackTrace(); 
} 
try { 
    String json = response.body().string(); 
} catch (IOException e) { 
    e.printStackTrace(); 
}

Edit: this is the php file that I use to insert the picture:

<?php
$response = array();
if (isset($_POST['image']))
{
$image = $_POST['image'];
require_once __DIR__ . '/db_connect.php';
$db = new DB_CONNECT();
$result = $db->query("INSERT INTO images(image) VALUES('$image')");
if ($result) {
$response["success"] = 1;
$response["message"] = "Product successfully created.";
echo json_encode($response);
} else {
$response["success"] = 0;
$response["message"] = "Oops! An error occurred.";
echo json_encode($response);
}
} else {
$response["success"] = 0;
$response["message"] = "missing fields";
echo json_encode($response);
}
?>

Answer 1

For image uploads you can always go for multipart part upload rather than converting it into base64. If you are using retrofit, the implementation will be easier.

I am adding the php and the android code to do it. I assume you are using httpurlconnection and not retrofit.

PHP

  <?php
            $target_dir = "uploads/";
            $target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);
            $uploadOk = 1;
            $imageFileType = pathinfo($target_file,PATHINFO_EXTENSION);
            // Check if image file is a actual image or fake image
            if(isset($_POST["submit"])) {
                $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);
                if($check !== false) {
                    echo "File is an image - " . $check["mime"] . ".";
                    $uploadOk = 1;
                } else {
                    echo "File is not an image.";
                    $uploadOk = 0;
                }
            }
            // Check if file already exists
            if (file_exists($target_file)) {
                echo "Sorry, file already exists.";
                $uploadOk = 0;
            }
            // Check file size
            if ($_FILES["fileToUpload"]["size"] > 500000) {
                echo "Sorry, your file is too large.";
                $uploadOk = 0;
            }
            // Allow certain file formats
            if($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg"
            && $imageFileType != "gif" ) {
                echo "Sorry, only JPG, JPEG, PNG & GIF files are allowed.";
                $uploadOk = 0;
            }
            // Check if $uploadOk is set to 0 by an error
            if ($uploadOk == 0) {
                echo "Sorry, your file was not uploaded.";
            // if everything is ok, try to upload file
            } else {
                if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_file)) {
                    echo "The file ". basename( $_FILES["fileToUpload"]["name"]). " has been uploaded.";
                } else {
                    echo "Sorry, there was an error uploading your file.";
                }
            }
            ?>

Android

fileInputStream = new FileInputStream(new File(_filePath));

        URL url = new URL(urlServer);
        connection = (HttpURLConnection) url.openConnection();

        // Allow Inputs & Outputs
        connection.setDoInput(true);
        connection.setDoOutput(true);
        connection.setUseCaches(false);

        // Enable POST method
        connection.setRequestMethod("POST");
        connection.setRequestProperty("Content-Type",
                "multipart/form-data;boundary=" + boundary);
        outputStream = new DataOutputStream(
                connection.getOutputStream());
        outputStream.writeBytes(twoHyphens + boundary + lineEnd);
        outputStream
                .writeBytes("Content-Disposition: form-data; name=\"fileToUpload\";filename=\""
                        + _filePath + "\"" + lineEnd);
        outputStream.writeBytes(lineEnd);

        bytesAvailable = fileInputStream.available();
        bufferSize = Math.min(bytesAvailable, maxBufferSize);
        buffer = new byte[bufferSize];

        // Read file
        bytesRead = fileInputStream.read(buffer, 0, bufferSize);
        // int contentLength = bytesAvailable+
        // header.getBytes().length+footer.getBytes().length;

        while (bytesRead > 0) {
            outputStream.write(buffer, 0, bufferSize);

            bytesAvailable = fileInputStream.available();
            bufferSize = Math.min(bytesAvailable, maxBufferSize);
            bytesRead = fileInputStream.read(buffer, 0, bufferSize);
        }

        outputStream.writeBytes(lineEnd);
        outputStream.writeBytes(twoHyphens + boundary + twoHyphens
                + lineEnd);

I also suggest you to use retrofit as a lot of network handling are done by the library itself.