Retrofit请求网络解析json

约定不等于承诺〃 2022-05-11 07:44 214阅读 0赞

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][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][Link 1]《《《《

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

效果浏览：

![70][]

[RecyclerView]: https://blog.csdn.net/qq_40881680/article/details/81837572
[http_www.qubaobei.com_ios_cf_dish_list.php_stage_id_1_limit_20_page_1]: http://www.qubaobei.com/ios/cf/dish_list.php?stage_id=1&limit=20&page=1
[Link 1]: https://blog.csdn.net/qq_40881680/article/details/82012180
[70]: /images/20220511/3183f3430d194743b5cb6cbb48d9310a.png