รัน apk โดยใช้ android studio ผลลัพธ์ได้ error ตามข้างล่าง เมื่อดู code ไม่มีอะไร error สีแดงขึ้นทุกบรรทัด ปัญหานี้ควรแก้ไขอย่างไร

package com.myapplication;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;

public class MyActivity extends Activity implements OnClickListener {

    Button btn_select;
    TextView tv_res;
    EditText txt_hn;
    EditText txt_name;
    EditText txt_age;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_my);
        tv_res = (TextView)findViewById(R.id.tv_res);
        txt_hn = (EditText)findViewById(R.id.txt_hn);
        txt_name = (EditText)findViewById(R.id.txt_name);
        txt_age = (EditText)findViewById(R.id.txt_age);
        btn_select = (Button)findViewById(R.id.btn_select);
        btn_select.setOnClickListener(this);
    }
    @Override
    public void onClick(View v){
        switch(v.getId()){
            case R.id.btn_select:
            {
                select();
                break;
            }
        }
    }
    
    public void clsText(){
        txt_hn.setText("");
        txt_name.setText("");
        txt_age.setText("");
    }

    public void select() {
        tv_res.setText("");
        InputStream is = null;
        String js_result = "";
        try {
            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost("http://localhost/testAndroid/get_data.php");
            HttpResponse response = httpclient.execute(httppost);
            HttpEntity entity = response.getEntity();
            is = entity.getContent();
        } catch (Exception e) {
            Log.d("log_err", "Error in http connection " + e.toString());
        }
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(is,"UTF-8"));
                    StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
            is.close();
            js_result = sb.toString();
        } catch (Exception e) {
            Log.e("log_tag", "Error converting result " + e.toString());
        }
        try {
            final JSONArray jArray = new JSONArray(js_result);
            for (int i = 0; i < jArray.length(); i++) {
                JSONObject jo = jArray.getJSONObject(i);
                String hn = jo.getString("hn");
                String name = jo.getString("name");
                String age = String.valueOf(jo.getInt("age"));
                String date_serv = jo.getString("date_serv");
                Log.d("log",hn+","+name+","+age+","+date_serv);
                tv_res.append(hn+","+name+","+age+","+date_serv+"\n");
            }
        } catch (JSONException e) {
            Log.e("log_tag", "Error parsing data " + e.toString());
        }
    }
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    tools:context=".MyActivity">

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Connect To Mysql Example" />
    <EditText
        android:id="@+id/txt_hn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="HN" >
    </EditText>

    <EditText
        android:id="@+id/txt_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Name-Lastname" />

    <EditText
        android:id="@+id/txt_age"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Age" />
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/btn_select"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Select" />

    </LinearLayout>
    <ScrollView
        android:id="@+id/scrollView1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"></ScrollView>
    <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">
</LinearLayout>
    <TextView
        android:id="@+id/tv_res"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

    </LinearLayout>
    <ScrollView

        android:layout_width="match_parent"
        android:layout_height="wrap_content" >
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent" ></LinearLayout>
    </ScrollView>
</LinearLayout>