Question

我刚刚使用Okhttp制作了一个简单的JSON解析程序，现在什么是OKhttp响应中的回调以及为什么我们使用它？

OkHttpClient okHttpClient=new OkHttpClient();

    Request request=new Request.Builder().url(url).build();

  okHttpClient.newCall(request).enqueue(new Callback() {
        @Override
        public void onFailure(Call call, IOException e) {

        }

        @Override
        public void onResponse(Call call, Response response) throws IOException {

        }
    });

Answer 1

Callbacks are used for asynchronous calls, in this case it will either return you the result from your network call to the url(Json/Xml data) in onsuccess or if there is an error onfailure will be called.
Error could be if connection didn't got through or connection timeout, response timeout, resource/address not valid, etc.

Answer 2

您已使用入队，这已将请求与其他队列一起放入了队列。与dobackground相同，将其从Mainthread中移除，并允许其他操作继续

回调是必需的，以便当网站有响应时，它知道使用了哪个请求，并通过回调将数据传回。

https://square.github.io/okhttp/3.x/okhttp/okhttp3/Callback.html

为什么我们在android中使用OKhttp的enqueue方法中使用Callback响应

2 个答案: