我使用以下类发送一个 http 请求并在我的 android 项目中获取返回的 XML 响应。但是在尝试发送请求时会抛出 UnknownHostException。请帮我解决这个问题。
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import android.os.AsyncTask;
import android.util.Xml;
class RequestTask extends AsyncTask<String, String, String>{
@Override
protected String doInBackground(String... uri) {
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response;
String responseString = null;
try {
response = httpclient.execute(new HttpGet(uri[0]));
StatusLine statusLine = response.getStatusLine();
if(statusLine.getStatusCode() == HttpStatus.SC_OK){
ByteArrayOutputStream out = new ByteArrayOutputStream();
response.getEntity().writeTo(out);
out.close();
responseString = out.toString();
} else{
//Closes the connection.
response.getEntity().getContent().close();
throw new IOException(statusLine.getReasonPhrase());
}
} catch (ClientProtocolException e) {
//TODO Handle problems..
} catch (IOException e) {
String s=e.toString();
System.out.println(s);
//TODO Handle problems..
}
return responseString;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
//Do anything with response..
System.out.println(result);
}
}