Android模拟器中未解决的主机异常

Question

我试图通过传递JSON参数来调用部署在App Engine上的servlet。以下是代码：

    public static String doPost(String url, String jsonData)
        throws ClientProtocolException, IOException {
    HttpClient httpclient = new DefaultHttpClient();
    HttpConnectionParams.setConnectionTimeout(httpclient.getParams(), 0); // Timeout

    HttpPost request = new HttpPost(url);
    StringEntity s = new StringEntity(jsonData);
    s.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE,"application/json"));
    HttpEntity entity = s;
    request.setEntity(entity);
    HttpResponse response = httpclient.execute(request);
    HttpEntity resEntity = response.getEntity();
    if (resEntity != null) {
        // Log.i("RESPONSE", EntityUtils.toString(resEntity));
        String responseData = EntityUtils.toString(resEntity).trim();
        return responseData;
    }
    return null;
}

我将网址传递给： http://abcd.appspot.com/

但是当代码在 模拟器 中执行时，我收到“java.net.UnknownHostException：Host is unresolved”错误。但是在 Android 2.2.1设备 中执行相同的代码时，一切正常。但是我无法在所有版本的 模拟器 中执行代码。

堆栈跟踪：

W/System.err(  987): java.net.UnknownHostException: Host is unresolved: aamjantaatest.appspot.com:80
W/System.err(  987):    at java.net.Socket.connect(Socket.java:1002) W/System.err(  987):   at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:117) 
W/System.err(  987):    at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:129) 
W/System.err(  987):    at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164) 
W/System.err(  987):    at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119) 
W/System.err(  987):    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:348)
W/System.err(  987):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555) 
W/System.err(  987):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487) 
W/System.err(  987):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465) 
W/System.err(  987):    at com.aamjantaa.android.service.Request.doPost(Request.java:62) 
W/System.err(  987):    at com.aamjantaa.android.intent.StoreListView$StoreListAsynTask.doInBackground(StoreListView.java:170) 
W/System.err(  987):    at com.aamjantaa.android.intent.StoreListView$StoreListAsynTask.doInBackground(StoreListView.java:1) 
W/System.err(  987):    at android.os.AsyncTask$2.call(AsyncTask.java:185) 
W/System.err(  987):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:256) 
W/System.err(  987):    at java.util.concurrent.FutureTask.run(FutureTask.java:122) 
W/System.err( 987):     at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:648) 
W/System.err(  987):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:673) 
W/System.err(  987):    at java.lang.Thread.run(Thread.java:1058)

Answer 1

可能是您的模拟器未连接到互联网。如果没有重新启动模拟器，请检查您的模拟器是否能够通过启动浏览器连接到互联网。

Answer 2

以上网址http://abcd.appspot.com/未在浏览器中打开，我已对其进行了检查，请再次查看

Answer 3

Unresolved Host Exception Android

检查此链接似乎是类似的问题，这对我有用

Answer 4

无论如何我自己找到了，这里是参考，

http://www.gitshah.com/2011/02/android-fixing-no-internet-connection.html