XML : Change spinner text color

I follow this answer to change spinner text color to black color, however I get cannot find symbol variable spinner_item . What's wrong here ?

Add_Details_Information.java

  public class Add_Details_Information extends AppCompatActivity {        private Spinner project;        @Override      protected void onCreate(Bundle savedInstanceState)      {          super.onCreate(savedInstanceState);          setContentView(R.layout.add_details_information);          addItemsOnSpinner(); // Spinner for project/service/training        }        public void addItemsOnSpinner()      {          project=(Spinner)findViewById(R.id.SpinnerProject);          List<String> list = new ArrayList<String>();          list.add("Pro-XXX-XXX");          list.add("TRN-XXX-XXX");          list.add("SRV-XXX-XXX");            ArrayAdapter<String> adapter = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.spinner_item, list);          adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);          project.setAdapter(adapter);      }  }    

spinner_item.xml (layout)

  <?xml version="1.0" encoding="utf-8"?>    <TextView      xmlns:android="http://schemas.android.com/apk/res/android"      android:layout_width="match_parent"      android:layout_height="wrap_content"      android:textSize="20sp"      android:gravity="left"      android:textColor="#000"      android:padding="5dip"/>    

add_details_information.xml

  <Spinner          android:layout_width="321dp"          android:layout_height="41dp"          android:layout_margin="10dp"          android:background="@drawable/round_corner_for_spinner"          android:layout_weight="0.07"          android:paddingLeft="20dp"          android:layout_x="14dp"          android:layout_y="59dp"          android:id="@+id/SpinnerProject" />    

round_color_for_spinner.xml (drawable)

  <?xml version="1.0" encoding="utf-8"?><!--  res/drawable/rounded_edittext.xml -->  <shape xmlns:android="http://schemas.android.com/apk/res/android"      android:padding="10dp"      android:shape="rectangle">      <solid android:color="@color/white" />      <stroke          android:width="3dip"          android:color="@color/light_gray" />      <corners          android:bottomLeftRadius="15dp"          android:bottomRightRadius="15dp"          android:topLeftRadius="15dp"          android:topRightRadius="15dp" />    </shape>    

Image

enter image description here

How to change the text color inside the drop-down list to black ? Thanks