UnknownHostException (webservice http-get)

Question

我有一段简单的代码，可以让get访问get服务。由于某种原因，它无法连接，并在日志unknownHostException中显示错误

代码如下：

String URL = "http://services.sapo.pt/EPG/GetChannelList";
String result = "";
final String tag = "Data received: ";

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    final Button btnSearch = (Button)findViewById(R.id.btnSearch);
    btnSearch.setOnClickListener(new Button.OnClickListener(){
        public void onClick(View v) {
            callWebService();
        }
    });

} // end onCreate()

public void callWebService(){
    HttpClient httpclient = new DefaultHttpClient();
    HttpGet request = new HttpGet(URL);
    ResponseHandler<String> handler = new BasicResponseHandler();

    try {
        result = httpclient.execute(request, handler);
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    httpclient.getConnectionManager().shutdown();
    Log.i(tag, result);
}

这是我清单的一部分

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

<application android:icon="@drawable/icon" android:label="@string/app_name">
    <activity android:name=".AndroidApp"
              android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

Answer 1

我找到了解决方案。我使用添加了标签的manifest中的GUI输入internet权限

<权限android:name"android.permission.INTERNET"/>

然后，我手动输入正确的标签，即：

Answer 2

不确定您是否已经检查过此选项，但请检查您是否在代理服务器或防火墙之后。这是一个way to configure the HttpClient for a proxy和官方apache documentation。