android 利用Retrofit2.0+RxJava2.0实现网络二次请求
利用Refrogit2.0与RxJava2.0结合的使用 达到了非常简单就可以完成请求网络
首先先导入依赖包：
compile 'com.squareup.retrofit2:retrofit:2.1.0'
compile 'com.squareup.retrofit2:converter-gson:2.1.0'
compile 'com.squareup.okhttp3:okhttp:3.2.0'
compile 'com.google.code.gson:gson:2.2.4'
compile 'io.reactivex.rxjava2:rxjava:2.0.1'
compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
compile 'com.jakewharton.retrofit:retrofit2-rxjava2-adapter:1.0.0'
implementation 'com.android.support:recyclerview-v7:26+'
implementation 'com.squareup.picasso:picasso:2.3.2' 添加网络权限：
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
这是访问的接口，接口里面还有一个接口，所以我们要进行二次请求：
http://www.ipanda.com/kehuduan/news/index.json请看ApiService接口代码：
public interface ApiService {
@GET//这是一次请求接口，也就是总接口url
Observable<MyBean> getData(@Url String url);
@GET//这是总接口里面的接口，也就是要请求的二次接口url_two
Observable<MyTwoBean> getData2(@Url String url_two);
}
封装的Constants类里面：
public class Constants {
//http://www.ipanda.com/kehuduan/news/index.json //一次请求接口
public static final String BASE_URL="http://www.ipanda.com/";
}MainActivity代码把，详细解释请看代码中的注释：
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import com.jakewharton.retrofit2.adapter.rxjava2.RxJava2CallAdapterFactory;
import com.squareup.picasso.Picasso;
import java.util.List;
import io.reactivex.Observable;
import io.reactivex.ObservableSource;
import io.reactivex.android.schedulers.AndroidSchedulers;
import io.reactivex.functions.Consumer;
import io.reactivex.functions.Function;
import io.reactivex.schedulers.Schedulers;
import okhttp3.OkHttpClient;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private Button btn_getdata;
private RecyclerView lv_recy;
private ImageView img;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
}
private void initView() {
btn_getdata = (Button) findViewById(R.id.btn_getdata);
btn_getdata.setOnClickListener(this);
lv_recy = (RecyclerView) findViewById(R.id.lv_recy);
lv_recy.setOnClickListener(this);
img = (ImageView) findViewById(R.id.img);
img.setOnClickListener(this);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_getdata:
OkHttpClient client = new OkHttpClient();
final Retrofit retrofit = new Retrofit.Builder()
.baseUrl(Constants.BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.addCallAdapterFactory(RxJava2CallAdapterFactory.create())
.client(client)
.build();
final ApiService apiService = retrofit.create(ApiService.class);
Observable<MyBean> observable = apiService.getData("kehuduan/news/index.json");
//请求数据必须切换到子线程
observable.subscribeOn(Schedulers.io())
//请求完数据要更新UI 切换到主线程
.observeOn(AndroidSchedulers.mainThread())
.doOnNext(new Consumer<MyBean>() {
@Override
public void accept(MyBean myBean) throws Exception {
Picasso.with(MainActivity.this).load(myBean.getData().getBigImg().get(0).getImage()).into(img);
}
})
.observeOn(Schedulers.io())
//flatMap操作符 注意Function中第一个泛型必须是总接口实体bean, 第二个泛型中的ObservableSource泛型是总接口里面的第二个接口的实体Bean
.flatMap(new Function<MyBean, ObservableSource<MyTwoBean>>() {
@Override
public ObservableSource<MyTwoBean> apply(MyBean myBean) throws Exception {
//获取到二次请求的接口
Observable<MyTwoBean> observable2 = apiService.getData2(myBean.getData().getListurl());
return observable2;
}
})
.observeOn(Schedulers.io()) //请求数据必须切换到子线程
.observeOn(AndroidSchedulers.mainThread()) //请求完数据要更新UI 切换到主线程
.subscribe(new Consumer<MyTwoBean>() {
@Override
public void accept(MyTwoBean myTwoBean) throws Exception {
List<MyTwoBean.ListBean> beanList = myTwoBean.getList();
MyRecyAdapter adapter = new MyRecyAdapter(beanList, MainActivity.this);
LinearLayoutManager manager = new LinearLayoutManager(MainActivity.this, LinearLayoutManager.VERTICAL, false);
lv_recy.setLayoutManager(manager);
lv_recy.setAdapter(adapter);
}
});
break;
}
}
}
来看MainActivity中布局代码：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.example.administrator.mytwourl.MainActivity">
<Button
android:id="@+id/btn_getdata"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="点击请求数据" />
<ImageView
android:id="@+id/img"
android:layout_width="match_parent"
android:layout_height="200dp" />
<android.support.v7.widget.RecyclerView
android:id="@+id/lv_recy"
android:layout_width="match_parent"
android:layout_height="match_parent"></android.support.v7.widget.RecyclerView>
</LinearLayout>
RecyView的适配器代码，
package com.example.administrator.mytwourl;
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import com.squareup.picasso.Picasso;
import java.util.List;
/**
* Created by Administrator on 2018/4/28.
*/
public class MyRecyAdapter extends RecyclerView.Adapter<MyRecyAdapter.ViewHolder> {
List<MyTwoBean.ListBean> beanList;
private Context context;
public MyRecyAdapter(List<MyTwoBean.ListBean> beanList, Context context) {
this.beanList = beanList;
this.context = context;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View inflate = LayoutInflater.from(context).inflate(R.layout.item_recy, parent, false);
ViewHolder holder = new ViewHolder(inflate);
return holder;
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
Picasso.with(context).load(beanList.get(position).getPicurl()).into(holder.img);
holder.txt_title.setText(beanList.get(position).getTitle());
}
@Override
public int getItemCount() {
return beanList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
private final ImageView img;
private final TextView txt_title;
public ViewHolder(View itemView) {
super(itemView);
img = itemView.findViewById(R.id.img);
txt_title = itemView.findViewById(R.id.txt_title);
}
}
}
适配器需要布局:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<ImageView
android:id="@+id/img"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/txt_title"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>