как можно разделить одну строку на две

так у меня программа, где происходит регистрация с помощью retrofit.  
тут я щас кину весь нужный код.

UI

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/supportop_view_bg"
android:orientation="vertical">
<android.support.design.widget.TextInputLayout
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:layout_marginHorizontal="20dp"
    android:layout_marginTop="50dp"
    android:background="@drawable/style">
    <android.support.design.widget.TextInputEditText
        android:id="@+id/name"
        android:layout_width="match_parent"
        android:layout_height="30dp"
        android:layout_marginTop="40dp"
        android:background="@android:color/transparent"
        android:hint="@string/name_surname"
        android:paddingLeft="10dp" />
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:layout_marginHorizontal="20dp"
    android:layout_marginTop="10dp"
    android:background="@drawable/style">
    <android.support.design.widget.TextInputEditText
        android:id="@+id/username"
        android:layout_width="match_parent"
        android:layout_height="30dp"
        android:layout_marginTop="10dp"
        android:background="@android:color/transparent"
        android:hint="@string/username"
        android:paddingLeft="10dp" />
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:layout_marginHorizontal="20dp"
    android:layout_marginTop="10dp"
    android:background="@drawable/style">
    <android.support.design.widget.TextInputEditText
        android:id="@+id/email"
        android:layout_width="match_parent"
        android:layout_height="30dp"
        android:layout_marginTop="10dp"
        android:background="@android:color/transparent"
        android:hint="@string/email_log"
        android:inputType="textEmailAddress"
        android:paddingLeft="10dp" />
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:layout_marginHorizontal="20dp"
    android:layout_marginTop="10dp"
    android:background="@drawable/style"
    app:passwordToggleEnabled="true">
    <EditText
        android:id="@+id/password"
        android:layout_width="match_parent"
        android:layout_height="30dp"
        android:layout_marginTop="10dp"
        android:background="@android:color/transparent"
        android:hint="@string/password_log"
        android:inputType="textPassword"
        android:paddingLeft="10dp" />
</android.support.design.widget.TextInputLayout>

<Button
    android:id="@+id/register"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginHorizontal="20dp"
    android:layout_marginTop="15dp"
    android:background="@drawable/corner_button"
    android:text="@string/send_verification_email"
    android:textAllCaps="false"
    android:textColor="#fff"
    android:textSize="15sp" />
<Button
    android:id="@+id/facebook"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginHorizontal="20dp"
    android:layout_marginTop="15dp"
    android:background="@drawable/corner_button_2"
    android:text="@string/f_log_in_with_facebook"
    android:textAllCaps="false"
    android:textColor="#fff"
    android:textSize="15sp" /> </LinearLayout>

Model class

public class SupportopObj {
@SerializedName("username")
@Expose
private String username;
@SerializedName("password")
@Expose
private String password;
@SerializedName("email")
@Expose
private String email;
@SerializedName("firstName")
@Expose
private String firstName;
@SerializedName("lastName")
@Expose
private String lastName;
public String getUsername() {
    return username;
}
public void setUsername(String username) {
    this.username = username;
}
public String getPassword() {
    return password;
}
public void setPassword(String password) {
    this.password = password;
}
public String getEmail() {
    return email;
}
public void setEmail(String email) {
    this.email = email;
}
public String getFirstName() {
    return firstName;
}
public void setFirstName(String firstName) {
    this.firstName = firstName;
}
public String getLastName() {
    return lastName;
}
public void setLastName(String lastName) {
    this.lastName = lastName;
}}

Registration part

public class FragmentRegistration extends Fragment {
View mainView;
EditText username, email, password, name;
Button button;
ApiClient pentairAPIClient = ApiClient.getInstance();
SupportopObj supportopObj = new SupportopObj();
SupportopObjActivate supportopObjActivate = new SupportopObjActivate();
@Override
public View onCreateView(LayoutInflater inflater,
                         @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    mainView = getLayoutInflater().inflate(R.layout.registration, container, false);
    username = mainView.findViewById(R.id.username);
    email = mainView.findViewById(R.id.email);
    password = mainView.findViewById(R.id.password);
    name = mainView.findViewById(R.id.name);
    button = mainView.findViewById(R.id.register);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            supportopObj.setUsername(username.getText().toString());
            supportopObj.setEmail(email.getText().toString());
            supportopObj.setPassword(password.getText().toString());              
            updateApp();
        }
    });
    return mainView;
}
public void updateApp() {
    FragmentRegistration context = this;
    Call<ResponseBody> call = pentairAPIClient.registration(supportopObj);
    call.enqueue(new Callback<ResponseBody>() {
        @Override
        public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
            if (response.isSuccessful()) {
            } else {
                Toast.makeText(getContext(), "Something went wrong",
                        Toast.LENGTH_SHORT).show();
            }
        }
        @Override
        public void onFailure(Call<ResponseBody> call, Throwable t) {
            Toast.makeText(getContext(), "Error...", Toast.LENGTH_SHORT).show();
        }
    });
}    
}}

вы тут видите да supportopObj.setUsername(username.getText().toString()); supportopObj.setEmail(email.getText().toString()); supportopObj.setPassword(password.getText().toString()); . это я как-бы присваиваю объектам из класса модели текст полученной из моих edittext , но тут у меня есть поле name это для firstname и lastname, как я могу разделить имя от фамилии и присвоить их классам модели?