HttpClient.execute (HttpPost) on Android 4.2 error
I’m following the site http://givemepass.blogspot.hk/2011/12/http-server.html try to connect to a PHP server using an android app to get messages.
GetServerMessage.java
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
public class GetServerMessage {
public String stringQuery(String url){
try
{
HttpClient httpclient = new DefaultHttpClient();
HttpPost method = new HttpPost(url);
HttpResponse response = httpclient.execute(method);
HttpEntity entity = response.getEntity();
if(entity != null){
return EntityUtils.toString(entity);
}
else{
return "No string.";
}
}
catch(Exception e){
return "Network problem";
}
}
}
GetPhpServerMessageDemoActivity.java
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
public class GetPhpServerMessageDemoActivity extends Activity {
/** Called when the activity is first created. */
private TextView textView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
textView = (TextView)findViewById(R.id.text_view);
GetServerMessage message = new GetServerMessage();
String msg = message.stringQuery("http://192.168.1.88/androidtesting.php");
textView.setText("Server message is "+msg);
}
}
I’m trying to download the Android app project from this site http://uploadingit.com/file/d4632ekfpwjiupyn/GetPhpServerMessageDemo2.zip running on my phone and it works.
But when I start a new project (Minimuim Requied SDK: API8, Target SDK: API17, Compile: API17) and copy both java code. I ADDED PERMISSIONS ANDROID.PERMISSION.INTERNET
, SO I DON’T KNOW WHERE THE PROBLEM IS, I JUST KNOW WHEN RUNNING HTTPRESPONSE = httpclient.execute(method);
An error occurs and returns the string “Network problem”.
Solution
Update: If you are using kotlin, use coroutines for threading. AsncTask is no longer used.
You are running network-related operations on a UI thread. You get NetworkOnMainThreadException
post honeycomb.
Use Thread
or Asynctask
Invoke an asynchronous task
new TheTask().execute("http://192.168.1.88/androidtesting.php");
Asynchronous tasks
http://developer.android.com/reference/android/os/AsyncTask.html
class TheTask extends AsyncTask<String,String,String>
{
@Override
protected String onPostExecute(Void result) {
TODO Auto-generated method stub
super.onPostExecute(result);
update textview here
textView.setText("Server message is "+result);
}
@Override
protected void onPreExecute() {
TODO Auto-generated method stub
super.onPreExecute();
}
@Override
protected String doInBackground(String... params) {
try
{
HttpClient httpclient = new DefaultHttpClient();
HttpPost method = new HttpPost(params[0]);
HttpResponse response = httpclient.execute(method);
HttpEntity entity = response.getEntity();
if(entity != null){
return EntityUtils.toString(entity);
}
else{
return "No string.";
}
}
catch(Exception e){
return "Network problem";
}
}
}
Update HttpClient is deprecated in API 23. Use HttpUrlConnection
.
http://developer.android.com/reference/java/net/HttpURLConnection.html