Android Material Design Widget Spinner

Spinner_material_design.xml

			<RelativeLayout
                            android:layout_width="match_parent"
                            android:layout_height="match_parent">

                            <Spinner
                                android:id="@+id/subject_spinner"
                                android:layout_width="1dp"
                                android:layout_height="1dp"
                                android:layout_alignParentTop="true"
                                android:layout_centerHorizontal="true"
                                android:layout_marginTop="60dp"
                                android:background="#000000"
                                android:focusable="true"
                                android:focusableInTouchMode="true"
                                android:spinnerMode="dialog"
                                android:visibility="gone" />


                            <android.support.design.widget.TextInputLayout
                                android:id="@+id/input_layout_subject"
                                android:layout_width="match_parent"
                                android:layout_height="wrap_content"
                                android:theme="@style/TextLabel"
                                app:errorTextAppearance="@style/error_appearance">

                                <EditText
                                    android:id="@+id/input_subject"
                                    android:layout_width="match_parent"
                                    android:layout_height="wrap_content"
                                    android:hint="@string/subject_label"
                                    android:inputType="textEmailSubject"
                                    android:maxLength="55"
                                    android:textColor="@color/editText" />
                            </android.support.design.widget.TextInputLayout>
   
            </RelativeLayout>

strings.xml

 <string-array name="subjects">
        <item>S1</item>
        <item>S2</item>
        <item>S3</item>
        <item>SN..</item>
    </string-array>

<string name="subject_label">Subject</string>

TestActivity.java

        final Spinner spinnerSubject = (Spinner) findViewById(R.id.subject_spinner);
        final EditText subject_input = (EditText) findViewById(R.id.input_subject);
        final String[] subjets = getResources().getStringArray(R.array.subjects);
        
        dataAdapterForSpinner = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item,subjets);
        dataAdapterForSpinner.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinnerSubject.setAdapter(dataAdapterForSpinner);

        subject_input.setKeyListener(null);

        subject_input.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                spinnerSubject.setVisibility(View.VISIBLE);
                spinnerSubject.performClick();
            }
        });

        subject_input.setOnFocusChangeListener(new View.OnFocusChangeListener() {
          @Override
          public void onFocusChange(View view, boolean b) {
              if(b){
                  spinnerSubject.setVisibility(View.VISIBLE);
                  spinnerSubject.performClick();
              }
              else{
                  spinnerSubject.setVisibility(View.GONE);
              }
             }
         });
        
        spinnerSubject.setOnItemSelectedListener(new OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView<?> parent, View view,int position, long id) {
                subject_input.setText(spinnerSubject.getSelectedItem().toString()); //this is taking the first value of the spinner by default.
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {
                // TODO Auto-generated method stub
                subject_input.setText("");
            }
        });