java - Android使用HttpURLConnection简单的获取百度的首页源码失败？

Question

就是想很简单的获取百度的源码，开了一个子线程，使用HttpURLConnection，却不知到为什么一直获取失败。求高手告之原因。

public class MainActivity extends Activity implements View.OnClickListener
{

    public static final int SHOW_RESPONSE = 0;

    private Button sendRequest;

    private TextView responseText;

    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);
            }
        }

    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.web_layout);
        sendRequest = (Button) findViewById(R.id.send_request);
        responseText = (TextView) findViewById(R.id.response_text);
        sendRequest.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        if (v.getId() == R.id.send_request) {
            sendRequestWithHttpURLConnection();
        }

    }



    private void sendRequestWithHttpURLConnection() {
        // 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("http://www.baidu.com/");
                    connection = (HttpURLConnection) url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.setConnectTimeout(8000);
                    connection.setReadTimeout(8000);
                    connection.setDoInput(true);
                    connection.setDoOutput(true);
                    if(connection.getResponseCode()!=200)
                    {
                        Log.d("haha", "code is "+connection.getResponseCode());
                    }
                    InputStream in = connection.getInputStream();
                    // 下面对获取到的输入流进行读取
                    BufferedReader reader = new BufferedReader(
                            new InputStreamReader(in));
                    StringBuilder response = new StringBuilder();

                    String line;
                    while ((line = reader.readLine()) != null) {
                        response.append(line);
                    }
                    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.toString();
                    handler.sendMessage(message);
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                    if (connection != null) {
                        connection.disconnect();
                    }
                }
            }
        }).start();
    }


}

布局代码：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:orientation="vertical" >

    <Button
        android:id="@+id/send_request"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Send Request" />

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

        <TextView
            android:id="@+id/response_text"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
    </ScrollView>

</LinearLayout>

log里没有任何异常信息报出，url的返回码为302.
真的很疑惑，因为代码检查过很多次了觉得没有问题，求助！！！！！

Answer 1

Tidak ada yang salah dengan kod ini sendiri 302 juga telah memberitahu anda tentang masalah tersebut. tetapi https://www.baidu.com berada dalam Halaman boleh diakses pada pelayar semula, apa masalahnya? Ini kerana Baidu membuat lompatan dan melompat anda secara automatik ke https://www.baidu.com Lompatan ini dilakukan oleh halaman 302 Tindakan ini sangat pantas dan pada dasarnya tidak dapat dikesan. Itulah sebabnya anda mendapat 302 bukannya 200. http://www.baidu.com

Answer 2

Betul kata orang di atas.
Jadi anda perlu melakukan dua perkara:

1. Ganti url dengan: https://www.baidu.com

2. Ganti URLConnection, HttpURLConnection dengan HttpsURLConnection.