使用Json StringRequest和PHP将图像从Android库中上传到服务器？

Question

我想将图像上传到服务器，该怎么做才能在服务器中保存图像。

我想使用Json的String请求将二进制文件图像的值传递给服务器。 在服务器端，我使用php保存文件，如下所示：

            $binary=base64_decode($base);
  header('Content-Type: bitmap; charset=utf-8');
   // Images will be saved under 'www/imgupload/uplodedimages' folder
      $file = fopen('../uploadedimages/'.$filename, 'wb');
      // Create File

     fwrite($file, $binary);
     fclose($file);

Answer 1

使用Base64 Utility Class将选定的图像转换为String。 使用AsynTask可以将Image编码为String，因为它运行时间很长。 编码完成后，调用“ triggerImageUpload”方法，该方法将启动图像上传。

public void encodeImagetoString() {
        new AsyncTask<Void, Void, String>() {

        protected void onPreExecute() {

        };

        @Override
        protected String doInBackground(Void... params) {
            BitmapFactory.Options options = null;
            options = new BitmapFactory.Options();
            options.inSampleSize = 3;
            bitmap = BitmapFactory.decodeFile(imgPath,
                    options);
            ByteArrayOutputStream stream = new ByteArrayOutputStream();
            // Must compress the Image to reduce image size to make upload easy
            bitmap.compress(Bitmap.CompressFormat.PNG, 50, stream); 
            byte[] byte_arr = stream.toByteArray();
            // Encode Image to String
            encodedString = Base64.encodeToString(byte_arr, 0);
            return "";
        }

        @Override
        protected void onPostExecute(String msg) {
            prgDialog.setMessage("Calling Upload");
            // Put converted Image string into Async Http Post param
            params.put("image", encodedString);
            // Trigger Image upload
            triggerImageUpload();
        }
    }.execute(null, null, null);
}

现在，使用AsyncHttp库将编码后的字符串通过HTTP发送到PHP服务器。 （您可以使用任何HTTP库）。 编码完成后，将在onPostExecute方法中调用方法“ triggerImageUpload”：

public void triggerImageUpload() {
        makeHTTPCall();
    }

将编码后的字符串发布到PHP服务器：

public void makeHTTPCall() {
    prgDialog.setMessage("Invoking Php");        
    AsyncHttpClient client = new AsyncHttpClient();
    // Don't forget to change the IP address to your LAN address. Port no as well.
    client.post("http://192.168.2.5:9000/imgupload/upload_image.php",
            params, new AsyncHttpResponseHandler() {
                // When the response returned by REST has Http
                // response code '200'
                @Override
                public void onSuccess(String response) {
                    // Hide Progress Dialog
                    prgDialog.hide();
                    Toast.makeText(getApplicationContext(), response,
                            Toast.LENGTH_LONG).show();
                }

                // When the response returned by REST has Http
                // response code other than '200' such as '404',
                // '500' or '403' etc
                @Override
                public void onFailure(int statusCode, Throwable error,
                        String content) {
                    // Hide Progress Dialog
                    prgDialog.hide();
                    // When Http response code is '404'
                    if (statusCode == 404) {
                        Toast.makeText(getApplicationContext(),
                                "Requested resource not found",
                                Toast.LENGTH_LONG).show();
                    }
                    // When Http response code is '500'
                    else if (statusCode == 500) {
                        Toast.makeText(getApplicationContext(),
                                "Something went wrong at server end",
                                Toast.LENGTH_LONG).show();
                    }
                    // When Http response code other than 404, 500
                    else {
                        Toast.makeText(
                                getApplicationContext(),
                                "Error Occured \n Most Common Error: \n1. Device not connected to Internet\n2. Web App is not deployed in App server\n3. App server is not running\n HTTP Status code : "
                                        + statusCode, Toast.LENGTH_LONG)
                                .show();
                    }
                }
            });
}

现在，根据PHP服务器返回的HTTP响应，通知用户有关上传状态（成功上传或失败）。

哇，我们做到了。