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!!!!!
高洛峰2017-04-18 10:32:48
这段代码本身没什么问题,302也已经提示你问题所在了,你访问的URL地址有问题,百度现在是全站https,所以你应该使用https://www.baidu.com
来进行测试,但http://www.baidu.com
在浏览器上又能访问到页面,是什么问题呢?这是因为百度做了跳转,自动给你跳转到https://www.baidu.com上,这个跳转由一个302页面来进行,动作很快,基本察觉不到。这就是为什么你得到302而不是200的原因。
怪我咯2017-04-18 10:32:48
楼上说的对。
所以你需要做两件事:
替换url为:https://www.baidu.com
替换URLConnection,HttpURLConnection 替换为 HttpsURLConnection.