Android网络请求之HttpURLConnection/HttpClient

首先必须声明权限：

<uses-permission android:name="android.permission.INTERNET"/>

API接口：https://www.juhe.cn/docs/api/id/46

1 HttpURLConnection

Get

private void httpURLConnectionGet() {
        // 开启线程来发起网络请求
        new Thread(new Runnable() {
            @Override
            public void run() {
                HttpURLConnection connection = null;
                try {
                    URL url = new URL(URL_GET+"key="+API_KEY+"&menu="+MENU);
                    //获取HttpURLConnection实例
                    connection = (HttpURLConnection) url.openConnection();
                    //GET表示希望从服务器获取数据
                    connection.setRequestMethod("GET");
                    //设置连接超时、读取超时的毫秒数
                    connection.setConnectTimeout(8000);
                    connection.setReadTimeout(8000);
                    getURLConnectionResponse(connection);
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                    if (connection != null) {
                        //关闭HTTP连接
                        connection.disconnect();
                    }
                }
            }
        }).start();
    }

Post

private void httpURLConnectionPost() {
        // 开启线程来发起网络请求
        new Thread(new Runnable() {
            @Override
            public void run() {
                HttpURLConnection connection = null;
                try {
                    URL url = new URL(URL_POST);
                    //获取HttpURLConnection实例
                    connection = (HttpURLConnection) url.openConnection();
                    //GET表示希望从服务器获取数据
                    connection.setRequestMethod("POST");
                    DataOutputStream out = new DataOutputStream(connection.getOutputStream());
                    //不解码会乱码
                    out.writeBytes("key="+API_KEY+"&menu="+URLEncoder.encode(MENU,"UTF-8"));
                    //设置连接超时、读取超时的毫秒数
                    connection.setConnectTimeout(8000);
                    connection.setReadTimeout(8000);
                    getURLConnectionResponse(connection);
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                    if (connection != null) {
                        //关闭HTTP连接
                        connection.disconnect();
                    }
                }
            }
        }).start();
    }

getURLConnectionResponse

private void getURLConnectionResponse(HttpURLConnection connection) throws Exception {
        //获取服务器返回的输入流
        InputStream in = connection.getInputStream();
        // 利用BufferedReader对服务器返回的流进行读取
        BufferedReader reader = new BufferedReader(
                new InputStreamReader(in));
        StringBuilder response = new StringBuilder();
        String line;
        while ((line = reader.readLine()) != null) {
            response.append(line);
        }
        sendMessage(response.toString());
    }

2 HttpClient

Get

private void httpClientGet() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    //创建一个HttpClient实例
                    HttpClient httpClient = new DefaultHttpClient();
                    //创建一个HttpGet对象以发起GET请求
                    //指定访问的服务器地址是电脑本机
                    HttpGet httpGet = new HttpGet(URL_GET+"key="+API_KEY+"&menu="+MENU);
                    HttpResponse httpResponse = httpClient.execute(httpGet);
                    getHttpClient(httpResponse);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }

Post

private void httpClientPost() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    //创建一个HttpClient实例
                    HttpClient httpClient = new DefaultHttpClient();
                    //创建一个HttpGet对象以发起GET请求
                    //指定访问的服务器地址是电脑本机
                    HttpPost httpPost = new HttpPost(URL_POST);
                    
                    List<NameValuePair> params = new ArrayList<NameValuePair>();
                    params.add(new BasicNameValuePair("key", API_KEY));
                    params.add(new BasicNameValuePair("menu", MENU));
                    UrlEncodedFormEntity entity = new UrlEncodedFormEntity(params, "UTF-8");
                    httpPost.setEntity(entity);
                    
                    HttpResponse httpResponse = httpClient.execute(httpPost);
                    getHttpClient(httpResponse);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }

getHttpClient

private void getHttpClient(HttpResponse httpResponse) throws Exception{
        if (httpResponse.getStatusLine().getStatusCode() == 200) {
            // 请求和响应都成功了
            HttpEntity entity1 = httpResponse.getEntity();
            String response = EntityUtils.toString(entity1, "utf-8");
            //parseJSONWithJSONObject(response);
            sendMessage(response);
        }
    }

sendMessage

private void sendMessage(String response) {
        Message message = new Message();
        message.what = SHOW_RESPONSE;
        // 将服务器返回的结果存放到Message中
        message.obj = response;
        handler.sendMessage(message);
    }

 handler

//子线程无法操作UI,要借用Handler将服务器返回的内容显示出来
    private Handler handler = new Handler() {
        public void handleMessage(Message msg) {
            switch (msg.what) {
            case SHOW_RESPONSE:
                String response = (String) msg.obj;
                // 在这里进行UI操作，将结果显示到界面上
                responseText.setText(response);
            }
        }
    };