《第一行代码》第二版学习笔记（8）—

《第一行代码》第二版学习笔记（8）——网络技术

文章目录

一、Http
- 1、HttpURLConnection
- 2、OKHttp
二、解析JSON格式数据
- 1、使用JSONObject
- 2、使用GSON解析JSON数据

在这里插入图片描述

一、Http

1、HttpURLConnection

 public void run() {HttpURLConnection connection = null;BufferedReader reader = null;try {URL url = new URL("http://www.baidu.com");connection = (HttpURLConnection) url.openConnection();connection.setRequestMethod("GET");connection.setConnectTimeout(8000);connection.setReadTimeout(8000);InputStream in = connection.getInputStream();//                    下面对获取到的输入流进行处理reader = new BufferedReader(new InputStreamReader(in));StringBuilder response = new StringBuilder();String line;while ((line = reader.readLine()) != null){response.append(line);}showRespnse(response.toString());}catch (Exception e){e.printStackTrace();}finally {if (reader != null){try {reader.close();}catch (IOException e){e.printStackTrace();}}if (connection != null){connection.disconnect();}}}}).start();}

2、OKHttp

导入依赖：implementation 'com.squareup.okhttp3:okhttp:3.10.0'

    private void sendRequestWithOkHttp(){new Thread(new Runnable() {@Overridepublic void run() {try {OkHttpClient client = new OkHttpClient();Request request = new Request.Builder().url("http://www.baidu.com").build();Response response = client.newCall(request).execute();String responseData = response.body().string();showRespnse(responseData);} catch (Exception e) {e.printStackTrace();}}}).start();}

二、解析JSON格式数据

1、使用JSONObject

    private void parseJSONWithJSONObject(String jsonData) {try {JSONArray jsonArray = new JSONArray(jsonData);for (int i = 0; i < jsonArray.length(); i++) {JSONObject jsonObject = jsonArray.getJSONObject(i);String id = jsonObject.getString("id");String name = jsonObject.getString("name");String version = jsonObject.getString("version");Log.d(TAG,"id is " + id);Log.d(TAG,"name is " + name);Log.d(TAG,"version is " + version);}} catch (JSONException e) {e.printStackTrace();}}

2、使用GSON解析JSON数据

导入依赖：implementation 'com.google.code.gson.2.10.1' 主要是将一个JSON格式的字符串自动映射成一个对象，无需手动解析。

假如有个Person类，包含name和age字段，调用如下代码就可以将JSON数据解析成一个Person对象了。

Gson gson = new Gson();
Person person = gson.fromJson(jsonData,Person.class);

如果是JSON数组，需要借助TypeToken将期望的数据类型传入到fromJson方法中，如下所示：

List<Person> people = gson.fromJson(jsonData,new TypeToken<List<Person>>(){}.getType());

    private void parseJSONWithGSON(String jsonData){Gson gson = new Gson();List<App> appList = gson.fromJson(jsonData,new TypeToken<List<App>>(){}.getType());for (App app : appList){Log.d(TAG,"id is " + app.getId());Log.d(TAG,"name is " + app.getName());Log.d(TAG,"version is " + app.getVersion());}}