自定义列表视图没有'；t显示项目

我从互联网上重写了一些代码，当我尝试它时，listview没有显示任何内容，只是一个空白活动这是代码：

Adapter.java:

public class Adapter extends BaseAdapter{
    private Activity activity;
    private LayoutInflater inflater;
    private List<DataAnggota> items;
    public Adapter(Activity activity, List<DataAnggota> items) {
        this.activity = activity;
        this.items = items;
    }
    @Override
    public int getCount() {
        return items.size();
    }
    @Override
    public Object getItem(int location) {
        return items.get(location);
    }
    @Override
    public long getItemId(int position) {
        return position;
    }
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (inflater == null)
            inflater = (LayoutInflater) activity
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        if (convertView == null)
            convertView = inflater.inflate(R.layout.view_user_list, null);
        TextView id = (TextView) convertView.findViewById(R.id.id);
        TextView nama = (TextView) convertView.findViewById(R.id.nama);
        TextView status = (TextView) convertView.findViewById(R.id.status);
        DataAnggota data = items.get(position);
        id.setText(data.getId_anggota());
        nama.setText(data.getNama());
        status.setText(data.getStatus());
        return convertView;
    }
}

ViewUser.java

public class ViewUser extends AppCompatActivity {
    ListView list;
    List<DataAnggota> itemList = new ArrayList<DataAnggota>();
    Adapter adapter;
    LayoutInflater inflater;
    String url_viewuser = "http://10.0.2.2/test/viewuser.php";
    private static final String TAG = MainActivity.class.getSimpleName();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_view_user);
        list = (ListView) findViewById(R.id.listView);
        adapter = new Adapter(ViewUser.this, itemList);
        list.setAdapter(adapter);
        callVolley();
    }
    private void callVolley(){
        itemList.clear();
        adapter.notifyDataSetChanged();
        // membuat request JSON
        JsonArrayRequest jArr = new JsonArrayRequest(url_viewuser, new Response.Listener<JSONArray>() {
            @Override
            public void onResponse(JSONArray response) {
                Log.d(TAG, response.toString());
                for (int i = 0; i < response.length(); i++) {
                    try {
                        JSONObject obj = response.getJSONObject(i);
                        DataAnggota item = new DataAnggota();
                        item.setId_anggota(obj.getString("id_anggota"));
                        item.setNama(obj.getString("nama"));
                        item.setStatus(obj.getString("status"));
                        itemList.add(item);
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }
                adapter.notifyDataSetChanged();
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                VolleyLog.d(TAG, "Error: " + error.getMessage());
            }
        });
        AppController.getInstance(ViewUser.this).addToRequestQueue(jArr);
    }
}

activity_view_user.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_view_user"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.rzproject.koperasi.ViewUser">
    <ListView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/listView"></ListView>
</RelativeLayout>

view_user_list.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/id"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/nama"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/status"/>
</LinearLayout>

viewuser.php

include "init.php";
    $query = mysql_query("SELECT * FROM anggota ORDER BY id_anggota ASC");
    $json = array();
    while($row = mysql_fetch_assoc($query)){
        $json[] = $row;
    }
    echo json_encode($json);
    mysql_close($con);

代码有错吗？请帮助