网络请求框架(二):volley使用之自定义请求

一.导入volley的依赖或jar包

二.仿照StringRequest写一个自定义的请求对象,这样可以把json解析成需要的javabean

1.定义一个类继承request

public class MyRequest extends Request {
    private static final String TAG = "MyRequest";
    //需要解析的json字符串的泛型
    private Class mClass;
    //解析成功后的接口对象,用于数据的回调
    private  Response.Listener mSuccessListener;
    
    public MyRequest(String url, Class clazz, Response.ErrorListener listener,Response.Listener successListener) {
        super(url, listener);
        //通过构造函数,传入需要的字段
        this.mClass=clazz;
        this.mSuccessListener=successListener;
    }

    
    @Override
    protected Response parseNetworkResponse(NetworkResponse response) {
        Gson gson =new Gson();
        //根据gson解析,把从网络获取的字节数据解析成javabean
        T t = gson.fromJson(new String(response.data), mClass);
        return Response.success(t, HttpHeaderParser.parseCacheHeaders(response));
    }

    //数据的回调
    @Override
    protected void deliverResponse(T t) {
        mSuccessListener.onResponse(t);

    }
}

二.javaBean

public class JavaBean {
    private static final String TAG = "JavaBean";


    public int retcode;


    public List data;
    public List extend;

    public static class DataBean {
        public int id;
        public String title;
        public int type;
 

        public List children;

        public static class ChildrenBean {
            public int id;
            public String title;
            public int type;
            public String url;
        }
    }
}









三.请求数据代码

public class MainActivity extends AppCompatActivity implements Response.ErrorListener, Response.Listener {
    public static final String HOST = "http://192.168.56.1:8080/zhbj/categories.json";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

    }
    /*volley请求三部曲
    一.创建请求对象(解析数据成功或失败通过接口回调)
    二.创建请求队列
    三,添加请求到队列,发起请求
    * 
    * */
    public void request(View view){
        //创建请求对象
        MyRequest request=new MyRequest<>(HOST,JavaBean.class,this,this);
        //创建请求队列
        RequestQueue queue = Volley.newRequestQueue(this);
       //添加请求
        queue.add(request);

    }

    @Override
    public void onErrorResponse(VolleyError volleyError) {

    }

    @Override
    public void onResponse(JavaBean javaBean) {
        List data = javaBean.data;
        Toast.makeText(this,data.size()+"个数" , Toast.LENGTH_SHORT).show();

    }
}