retrofit封装网络请求,retrofit post请求

懒得一大堆废话，说完实现最终目标，直接进入正题操作，直接上代码，看使用方法

 

实现目标：用Retrofit解析网络json，放到RecyclerView中

 

第一步，写好布局文件以及item，我这里用的RecyclerView,不知道RecyclerView就点进去看看，解析出来的格式就是，一个图片，一个文字，直接看布局文件和item。

加入依赖

implementation 'com.squareup.retrofit2:retrofit:2.3.0'
implementation 'com.squareup.retrofit2:converter-gson:2.3.0'

 

加入RecyclerView

<?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" tools:context=".MainActivity"> <android.support.v7.widget.RecyclerView android:id="@+id/recyclerView" android:layout_width="match_parent" android:layout_height="match_parent"></android.support.v7.widget.RecyclerView></LinearLayout>

item:

<?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"> <ImageView android:id="@+id/imageView" android:layout_width="0dp" android:layout_height="120dp" android:layout_weight="2" /> <TextView android:id="@+id/textView" android:layout_width="0dp" android:layout_height="120dp" android:layout_weight="3" android:gravity="center" /></LinearLayout>

 

之后写一个RecyclerView的适配器，用具加入图片和文字

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.MyHolder> { private Context context; private List<JavaBean.DataBean> data;//数据源集合 //构造方法 public RecyclerViewAdapter(Context context, List<JavaBean.DataBean> data) { this.context = context; this.data = data; } @NonNull @Override public MyHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) { View inflate = LayoutInflater.from(context).inflate(R.layout.item, viewGroup, false); return new MyHolder(inflate); } @Override public void onBindViewHolder(@NonNull MyHolder myHolder, int i) { Picasso.with(context).load(data.get(i).getPic()).into(myHolder.imageView);//加入图片 myHolder.textView.setText(data.get(i).getTitle());//加入名字 } @Override public int getItemCount() { return data.size();//返回集合size } public class MyHolder extends RecyclerView.ViewHolder { ImageView imageView; TextView textView; public MyHolder(@NonNull View itemView) { super(itemView); imageView = itemView.findViewById(R.id.imageView); textView = itemView.findViewById(R.id.textView); } }}

提供网络字符串:http://www.qubaobei.com/ios/cf/dish_list.php?stage_id=1&limit=20&page=1

 

写出解析类JavaBean类，即解析类！

 

接下来是重点，如何通过Retrofit获取网络数据，看java代码

Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://1604a.com/data/")//网络数据源，网址前半段 .addConverterFactory(GsonConverterFactory.create())//解析 .build();

 

创建接口，get请求方式，写入网址的后半段，即最后一个“/”之后的字符，像下面这么写

public interface MyInterface { @GET("ymdx.json") Call<JavaBean> gerRequest();}

 

接着使用这个接口

MyInterface myInterface = retrofit.create(MyInterface.class);Call<JavaBean> call = myInterface.gerRequest();

 

接下来写Call的一个方法enqueue，注释有详细标明

call.enqueue(new Callback<JavaBean>() { //成功 @Override public void onResponse(Call<JavaBean> call, Response<JavaBean> response) { //解析添加到创建的集合 arrayList = response.body().getData(); recyclerView.setLayoutManager(new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL)); recyclerView.setItemAnimator(new DefaultItemAnimator());//RecyclerView动画：默认动画 //使用适配器 recyclerView.setAdapter(new RecyclerViewAdapter(MainActivity.this,arrayList)); } //失败 @Override public void onFailure(Call<JavaBean> call, Throwable t) { Toast.makeText(MainActivity.this, "请求失败", Toast.LENGTH_SHORT).show(); } });

 

看一下完整的java代码

public class MainActivity extends AppCompatActivity { private List<JavaBean.DataBean> arrayList; private RecyclerView recyclerView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initView(); Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://1604a.com/data/") .addConverterFactory(GsonConverterFactory.create()) .build(); MyInterface myInterface = retrofit.create(MyInterface.class); Call<JavaBean> call = myInterface.gerRequest(); call.enqueue(new Callback<JavaBean>() { //成功 @Override public void onResponse(Call<JavaBean> call, Response<JavaBean> response) { //解析添加到创建的集合 arrayList = response.body().getData(); recyclerView.setLayoutManager(new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL)); recyclerView.setItemAnimator(new DefaultItemAnimator()); //使用适配器 recyclerView.setAdapter(new RecyclerViewAdapter(MainActivity.this,arrayList)); } //失败 @Override public void onFailure(Call<JavaBean> call, Throwable t) { Toast.makeText(MainActivity.this, "请求失败", Toast.LENGTH_SHORT).show(); } }); } private void initView() { recyclerView = (RecyclerView) findViewById(R.id.recyclerView); }}

 

》》》》快速实例化控件《《《《

 

最重要的一步，加入网络权限：<uses-permission android:name="android.permission.INTERNET"/>

 

效果浏览：