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() {
            @Override
            public 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());
        }
    }