在本地连接Android Studio应用程序与mysql服务器（Genymotion模拟器）

Question

我正在尝试通过php脚本将我的android应用程序与mysql数据库连接。我已经尝试了一切，没有什么进展顺利。那么请你告诉我为什么我会收到这个错误，我该如何修复它。我只想在屏幕上显示查询，所以我可以确定我已连接并继续编码。

import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class MainActivity extends AppCompatActivity {

    String category;
    String JSON_String;
    String json_string;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        new BackgroundTask().execute();
    }
    class BackgroundTask extends AsyncTask<Void, Void, String>
    {
        String json_url;

        @Override
        protected void onPreExecute() {
            json_url="http://10.0.2.3/webappdb/get_all_rows.php";//Script
            //super.onPreExecute();
        }

        @Override
        protected String doInBackground(Void... params) {
            try {

                URL url = new URL(json_url);
                HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
                InputStream inputStream = httpURLConnection.getInputStream();
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                StringBuilder stringBuilder = new StringBuilder();
                while ((JSON_String = bufferedReader.readLine())!=null){

                    stringBuilder.append(JSON_String + "\n");

                }

                bufferedReader.close();
                inputStream.close();
                httpURLConnection.disconnect();
                return stringBuilder.toString().trim();

            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }


            return null;
        }

        @Override
        protected void onProgressUpdate(Void... values) {
            super.onProgressUpdate(values);
        }

        @Override
        protected void onPostExecute(String result) {


            TextView textView = (TextView) findViewById(R.id.textview);
            textView.setText(result);
            json_string=result;



        }
    }
}

错误列表

04-01 07:40:12.580 26083-26083/? D/dalvikvm: Late-enabling CheckJNI
    04-01 07:40:12.600 26083-26089/? E/jdwp: Failed sending reply to debugger: Broken pipe
    04-01 07:40:12.600 26083-26089/? D/dalvikvm: Debugger has detached; object registry had 1 entries
    04-01 07:40:12.692 26083-26083/? W/dalvikvm: VFY: unable to find class referenced in signature (Landroid/view/SearchEvent;)
    04-01 07:40:12.692 26083-26083/? I/dalvikvm: Could not find method android.view.Window$Callback.onSearchRequested, referenced from method android.support.v7.view.WindowCallbackWrapper.onSearchRequested
    04-01 07:40:12.692 26083-26083/? W/dalvikvm: VFY: unable to resolve interface method 15039: Landroid/view/Window$Callback;.onSearchRequested (Landroid/view/SearchEvent;)Z
    04-01 07:40:12.692 26083-26083/? D/dalvikvm: VFY: replacing opcode 0x72 at 0x0002
    04-01 07:40:12.692 26083-26083/? I/dalvikvm: Could not find method android.view.Window$Callback.onWindowStartingActionMode, referenced from method android.support.v7.view.WindowCallbackWrapper.onWindowStartingActionMode
    04-01 07:40:12.692 26083-26083/? W/dalvikvm: VFY: unable to resolve interface method 15043: Landroid/view/Window$Callback;.onWindowStartingActionMode (Landroid/view/ActionMode$Callback;I)Landroid/view/ActionMode;
    04-01 07:40:12.692 26083-26083/? D/dalvikvm: VFY: replacing opcode 0x72 at 0x0002
    04-01 07:40:12.748 26083-26083/? I/dalvikvm: Could not find method android.content.res.TypedArray.getChangingConfigurations, referenced from method android.support.v7.widget.TintTypedArray.getChangingConfigurations
    04-01 07:40:12.748 26083-26083/? W/dalvikvm: VFY: unable to resolve virtual method 396: Landroid/content/res/TypedArray;.getChangingConfigurations ()I
    04-01 07:40:12.748 26083-26083/? D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002
    04-01 07:40:12.748 26083-26083/? I/dalvikvm: Could not find method android.content.res.TypedArray.getType, referenced from method android.support.v7.widget.TintTypedArray.getType
    04-01 07:40:12.748 26083-26083/? W/dalvikvm: VFY: unable to resolve virtual method 418: Landroid/content/res/TypedArray;.getType (I)I
    04-01 07:40:12.748 26083-26083/? D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002
    04-01 07:40:12.828 26083-26087/? D/dalvikvm: GC_CONCURRENT freed 180K, 15% free 2674K/3132K, paused 26ms+1ms, total 29ms
    04-01 07:40:12.996 26083-26083/? D/libEGL: loaded /system/lib/egl/libEGL_genymotion.so
    04-01 07:40:13.008 26083-26083/? D/libEGL: loaded /system/lib/egl/libGLESv1_CM_genymotion.so
    04-01 07:40:13.008 26083-26083/? D/libEGL: loaded /system/lib/egl/libGLESv2_genymotion.so
    04-01 07:40:13.076 26083-26083/? W/EGL_genymotion: eglSurfaceAttrib not implemented
    04-01 07:40:13.084 26083-26083/? E/OpenGLRenderer: Getting MAX_TEXTURE_SIZE from GradienCache
    04-01 07:40:13.100 26083-26083/? E/OpenGLRenderer: Getting MAX_TEXTURE_SIZE from Caches::initConstraints()

Error list