I'm trying to make my app communicate with the host PC (it will still be the case when running on a real phone). My PC itself communicates with a remote server : I wrote Java classes that send HTTP request and listen for incoming HTTP notifications. These classes run perfectly on my PC.
I adapted them a little bit in my Android app. But unfortunately, the application is unable to access to the Internet : all requests timeout. I double-checked authorizations : Internet access is allowed in my Manifest file and effectively appear in the application informations in the parameters menu. My emulator has full Internet access : I can browse the Internet, including websites on the host PC.
In order to eliminate a problem with the PC, I first tried to get "http://www.google.fr/index.html" : it perfectly works on my PC with the same class, but not on the emulator. I then tried to tcpdump the traffic as on the interface of the emulator as advised here: I didn't have any HTTP request.
I can't figure out why...
My emulator is running Android 2.3.3 (API level 10).
Here's my connection class (I tried it with a HTTPClient and had the same issue) : (I know the log statement "request sent" is not at the best place, it will be corrected :)
package com.example.myApp;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.SocketTimeoutException;
import java.net.URL;
import java.security.InvalidParameterException;
import android.util.Log;
public class ServerConnection {
private String url;
private String method;
private String body;
private String response;
private int responseCode;
private int DEFAULT_TIMEOUT = 4 * 1000;
private int READ_TIMEOUT = 6 * 1000;
private static String TAG = "ServerConnection";
/**
* Create a new HTTP connection in order to send requests, retrieve responses, delete resources or receive notifications
* method MUST BE GET, POST or DELETE.
* @param url
* @param port
* @param method
* @param body
* @throws InvalidParameterException
*/
public ServerConnection(String url, String method, String body) throws InvalidParameterException{
this.url = url;
this.method = method;
this.body = body;
Log.d(TAG,"ServerConnection instantiated with parameters");
if(this.method == "POST")
this.sendPost();
else if (this.method =="GET")
this.sendGet();
else if (this.method == "DELETE")
this.sendDelete();
else
throw new InvalidParameterException("Invalid HTTP method");
}
/**
* Sends a HTTP request that does not require any body : for example a GET or DELETE
* @param url
* @param method
* @throws InvalidParameterException
*/
public ServerConnection(String url, String method) throws InvalidParameterException{
this.url = url;
this.method = method;
Log.d(TAG,"HTTP Request instantiated without body");
if (this.method =="GET")
this.sendGet();
else if (this.method == "DELETE")
this.sendDelete();
else
throw new InvalidParameterException("Invalid HTTP method");
}
/**
* Send a POST request with the specified url, port, body arguments.
*
* @return
*/
public void sendPost(){
new Thread(new Runnable() {
public void run() {
HttpURLConnection connection = null;
Log.d(TAG,"Sending HTTP POST Request...");
try{
URL serverUrl = new URL(ServerConnection.this.url);
connection = (HttpURLConnection) serverUrl.openConnection();
InputStream is;
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/xml");
connection.setRequestProperty("Accept", "application/xml");
connection.setRequestProperty("Content-Length","" + Integer.toString(ServerConnection.this.body.getBytes().length));
connection.setUseCaches(false);
connection.setInstanceFollowRedirects(false);
connection.setConnectTimeout(DEFAULT_TIMEOUT);
connection.setReadTimeout(READ_TIMEOUT);
connection.connect();
OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream());
writer.write(ServerConnection.this.body);
writer.flush();
writer.close();
// Get the response
is = connection.getInputStream();
ServerConnection.this.response = getStringFromInputStream(is);
ServerConnection.this.responseCode = connection.getResponseCode();
} catch(SocketTimeoutException ex) {
ex.printStackTrace();
Log.d(TAG,"SocketTimeoutException");
ServerConnection.this.response = null;
return;
}catch(MalformedURLException ex) {
ex.printStackTrace();
Log.e(TAG,"MalformedURLException");
} catch (IOException ex) {
ex.printStackTrace();
Log.e(TAG,"IOException");
} finally {
connection.disconnect();
Log.d(TAG,"Request sent.");
}
}
}).start();
}
public void sendDelete(){
new Thread(new Runnable() {
public void run() {
HttpURLConnection connection = null;
Log.d(TAG,"Sending HTTP DELETE Request...");
try{
URL serverUrl = new URL(ServerConnection.this.url);
connection = (HttpURLConnection) serverUrl.openConnection();
InputStream is;
connection.setDoOutput(true);
connection.setRequestMethod("DELETE");
connection.setRequestProperty("Accept", "application/xml");
connection.setRequestProperty("Host", ServerConnection.this.url);
connection.setConnectTimeout(DEFAULT_TIMEOUT);
connection.setReadTimeout(READ_TIMEOUT);
connection.connect();
Log.d(TAG,"Connected");
// Get the response
is = connection.getInputStream();
ServerConnection.this.response = getStringFromInputStream(is);
ServerConnection.this.responseCode = connection.getResponseCode();
} catch(SocketTimeoutException ex) {
ex.printStackTrace();
Log.d(TAG,"SocketTimeoutException");
ServerConnection.this.response = null;
return;
}catch(MalformedURLException ex) {
ex.printStackTrace();
Log.d(TAG,"MalformedURLException");
} catch (IOException ex) {
ex.printStackTrace();
Log.d(TAG,"IOException");
} finally {
connection.disconnect();
Log.d(TAG,"Request sent.");
}
}
});
}
public void sendGet(){
new Thread(new Runnable() {
public void run() {
HttpURLConnection connection = null;
Log.d(TAG,"Sending HTTP GET Request...");
try{
InputStream is;
URL serverUrl = new URL(ServerConnection.this.url);
connection = (HttpURLConnection) serverUrl.openConnection();
connection.setDoOutput(true);
connection.setRequestMethod("GET");
connection.setRequestProperty("Accept", "application/xml");
connection.setRequestProperty("Host", ServerConnection.this.url);
connection.setConnectTimeout(DEFAULT_TIMEOUT);
connection.setInstanceFollowRedirects(false);
connection.connect();
Log.d(TAG,"Connecting for GET request");
// Get the response
ServerConnection.this.responseCode = connection.getResponseCode();
is = connection.getInputStream();
ServerConnection.this.response = getStringFromInputStream(is);
Log.d(TAG,"page received: " + ServerConnection.this.response);
} catch(SocketTimeoutException ex) {
ex.printStackTrace();
Log.d(TAG,"SocketTimeoutException while sending GET request");
ServerConnection.this.response = null;
}catch(MalformedURLException ex) {
ex.printStackTrace();
Log.e(TAG,"MalformedURLException");
} catch (IOException ex) {
ex.printStackTrace();
Log.e(TAG,"IOException");
} finally {
connection.disconnect();
Log.d(TAG,"Request sent.");
}
}
}).start();
}
private static String getStringFromInputStream(InputStream is) {
Log.d(TAG,"Converting InputStream to response String...");
BufferedReader br = null;
StringBuilder sxb = new StringBuilder();
String line;
try {
br = new BufferedReader(new InputStreamReader(is));
while ((line = br.readLine()) != null) {
sxb.append(line);
}
} catch (IOException e) {
Log.e(TAG,"IOException");
e.printStackTrace();
} finally {
if (br != null) {
try {
br.close();
} catch (IOException e) {
e.printStackTrace();
Log.e(TAG,"IOException");
}
}
}
return sxb.toString();
}
public int getResponseCode(){
return this.responseCode;
}
public String getResponse(){
return this.response;
}
@Override
public String toString() {
return "CTSConnection [url=" + url + ", method=" + method + ", body="
+ body + ", response=" + response + ", responseCode="
+ responseCode + "]";
}
}
When I launch ServerConnection cnx = new ServerConnection("http://www.google.fr/index.html","GET");, I get the following log:
08-30 14:42:43.072: D/ServerConnection(581): Sending HTTP GET Request...
08-30 14:42:43.203: D/ServerConnection(581): Connecting for GET request
08-30 14:42:43.252: W/System.err(581): java.io.FileNotFoundException: http://www.google.fr/index.html
08-30 14:42:43.252: W/System.err(581): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:521)
08-30 14:42:43.252: W/System.err(581): at com.example.myApp.ServerConnection$3.run(ServerConnection.java:205)
08-30 14:42:43.252: W/System.err(581): at java.lang.Thread.run(Thread.java:1019)
08-30 14:42:43.252: E/ServerConnection(581): IOException
08-30 14:42:43.252: D/ServerConnection(581): Request sent.
For a POST request (with a valid body), for example ServerConnection cnx = new SertverConnection(10.0.2.2:65005,"POST","xml_document_to_string") :
08-30 14:42:43.299: D/ServerConnection(581): Sending HTTP POST Request...
08-30 14:42:47.348: W/System.err(581): java.net.SocketTimeoutException: Connection timed out
08-30 14:42:47.365: W/System.err(581): java.net.SocketTimeoutException: Connection timed out
08-30 14:42:47.365: W/System.err(581): at org.apache.harmony.luni.platform.OSNetworkSystem.connect(Native Method)
08-30 14:42:47.365: W/System.err(581): at dalvik.system.BlockGuard$WrappedNetworkSystem.connect(BlockGuard.java:357)
08-30 14:42:47.365: W/System.err(581): at org.apache.harmony.luni.net.PlainSocketImpl.connect(PlainSocketImpl.java:204)
08-30 14:42:47.365: W/System.err(581): at org.apache.harmony.luni.net.PlainSocketImpl.connect(PlainSocketImpl.java:437)
08-30 14:42:47.365: W/System.err(581): at java.net.Socket.connect(Socket.java:983)
08-30 14:42:47.365: W/System.err(581): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.<init>(HttpConnection.java:75)
08-30 14:42:47.365: W/System.err(581): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.<init>(HttpConnection.java:48)
08-30 14:42:47.365: W/System.err(581): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection$Address.connect(HttpConnection.java:322)
08-30 14:42:47.365: W/System.err(581): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnectionPool.get(HttpConnectionPool.java:89)
08-30 14:42:47.365: W/System.err(581): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getHttpConnection(HttpURLConnectionImpl.java:285)
08-30 14:42:47.372: W/System.err(581): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.makeConnection(HttpURLConnectionImpl.java:267)
08-30 14:42:47.372: W/System.err(581): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:205)
08-30 14:42:47.372: W/System.err(581): at com.example.myApp.ServerConnection$1.run(ServerConnection.java:102)
08-30 14:42:47.382: W/System.err(581): at java.lang.Thread.run(Thread.java:1019)
08-30 14:42:47.382: D/ServerConnection(581): SocketTimeoutException
08-30 14:42:47.382: D/ServerConnection(581): Request sent.
Well, I really can't figure out where this problem comes from... any hint ?
Thanks in advance !
