步骤：
打开Android Studio，新建一个项目取名为MVPDemo。demo的功能很简单，就是点击按钮调用上面的那个测试接口，将请求下来的信息显示在屏幕上。
工程的目录结构：
在build.gradle中添加如下依赖：
compile 'com.squareup.retrofit2:retrofit:2.1.0' //添加Retrofit库
compile 'com.squareup.retrofit2:converter-gson:2.1.0' //返回的数据为json类型
compile 'com.squareup.retrofit2:adapter-rxjava:2.1.0' //使Rxjava与retrofit结合使用
compile 'io.reactivex:rxandroid:1.2.0' //引入RxAndroid
RetrofitHelper用于Retrofit的初始化：
public class RetrofitHelper {
private Context mCntext;
OkHttpClient client = new OkHttpClient();
GsonConverterFactory factory = GsonConverterFactory.create(new GsonBuilder().create());
private static RetrofitHelper instance = null;
private Retrofit mRetrofit = null;
public static RetrofitHelper getInstance(Context context){
if (instance == null){
instance = new RetrofitHelper(context);
}
return instance;
}
private RetrofitHelper(Context mContext){
mCntext = mContext;
init();
}
private void init() {
resetApp();
}
private void resetApp() {
mRetrofit = new Retrofit.Builder()
.baseUrl("https://wanandroid.com/wenda/comments/问答id/json")
.client(client)
.addConverterFactory(factory)
.addCallAdapterFactory(RxJavaCallAdapterFactory.create())
.build();
}
public RetrofitService getServer(){
return mRetrofit.create(RetrofitService.class);
}
}
RetrofitService代码：
public interface RetrofitService {
@GET("book/search")
Observable<Book> getSearchBooks(@Query("q") String name,
@Query("tag") String tag,
@Query("start") int start,
@Query("count") int count);
}
manager中DataManager更方便的调用了RetrofitService 中定义的方法：
public class DataManager {
private RetrofitService mRetrofitService;
public DataManager(Context context){
this.mRetrofitService = RetrofitHelper.getInstance(context).getServer();
}
public Observable<Book> getSearchBooks(String name,String tag,int start,int count){
return mRetrofitService.getSearchBooks(name,tag,start,count);
}
}
presenter主要用于网络的请求以及数据的获取，view就是将presenter获取到的数据进行展示。首先看view，创建两个接口类View和BookView,其中View是空的，主要用于和Android中的View区别开来：
public interface View {
}
让BookView继承自View ：
public interface BookView extends View {
void onSuccess(Book mBook);
void onError(String result);
}
定义一个基础Presenter进行网络请求：
public interface Presenter {
void onCreate();
void onStart();//暂时没用到
void onStop();
void pause();//暂时没用到
void attachView(View view);
void attachIncomingIntent(Intent intent);//暂时没用到
}
BookPresenter具体实现代码：
public class BookPresenter implements Presenter {
private DataManager manager;
private CompositeSubscription mCompositeSubscription;
private Context mContext;
private BookView mBookView;
private Book mBook;
public BookPresenter (Context mContext){
this.mContext = mContext;
}
@Override
public void onCreate() {
manager = new DataManager(mContext);
mCompositeSubscription = new CompositeSubscription();
}
@Override
public void onStart() {
}
@Override
public void onStop() {
if (mCompositeSubscription.hasSubscriptions()){
mCompositeSubscription.unsubscribe();
}
}
@Override
public void pause() {
}
@Override
public void attachView(View view) {
mBookView = (BookView)view;
}
@Override
public void attachIncomingIntent(Intent intent) {
}
public void getSearchBooks(String name,String tag,int start,int count){
mCompositeSubscription.add(manager.getSearchBooks(name,tag,start,count)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Observer<Book>() {
@Override
public void onCompleted() {
if (mBook != null){
mBookView.onSuccess(mBook);
}
}
@Override
public void onError(Throwable e) {
e.printStackTrace();
mBookView.onError("请求失败！！");
}
@Override
public void onNext(Book book) {
mBook = book;
}
})
);
}
}
可以调用这个接口方法来进行网络的请求了
先写一下页面的布局代码：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/activity_main"
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:orientation="vertical"
android:paddingTop="@dimen/activity_vertical_margin">
<TextView
android:id="@+id/text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="MVP+Retrofit+RxJava" />
<Button
android:id="@+id/button"
android:onClick="getFollowers"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="请求"/>
</LinearLayout>
界面一共两个控件如下:
Button：点击时进行网络请求
TextView:用于显示请求下来的数据
Activity中代码：
public class MainActivity extends AppCompatActivity {
private TextView text;
private Button button;
private BookPresenter mBookPresenter = new BookPresenter(this);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
text = (TextView)findViewById(R.id.text);
button = (Button)findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mBookPresenter.getSearchBooks("问答id", null, 0, 1);
}
});
mBookPresenter.onCreate();
mBookPresenter.attachView(mBookView);
}
private BookView mBookView = new BookView() {
@Override
public void onSuccess(Book mBook) {
text.setText(mBook.toString());
}
@Override
public void onError(String result) {
Toast.makeText(MainActivity.this,result, Toast.LENGTH_SHORT).show();
}
};
@Override
protected void onDestroy(){
super.onDestroy();
mBookPresenter.onStop();
}
}
最后在AndroidManifest中添加网络权限：
<uses-permission android:name="android.permission.INTERNET"/>
