How do I avoid going through the ProxySelector when making a connection with URLConnection or rather how to get a connection guaranteed free of whatever proxies Java knows about ?
I thought this was what Proxy.NO_PROXY was for. Quoting from the Javadoc:
A proxy setting that represents a DIRECT connection, basically telling
the protocol handler not to use any proxying
Yet such a connection will still go through the ProxySelector. I don't get it ??
I've made a small test to prove my point:
public static void main(String[] args) throws MalformedURLException, IOException {
ProxySelector.setDefault(new MyProxySelector());
URL url = new URL("http://foobar.com/x1/x2");
URLConnection connection = url.openConnection(Proxy.NO_PROXY);
connection.connect();
}
and a dummy ProxySelector which does nothing but log what is going on:
public class MyProxySelector extends ProxySelector {
#Override
public List<Proxy> select(URI uri) {
System.out.println("MyProxySelector called with URI = " + uri);
return Collections.singletonList(Proxy.NO_PROXY);
}
#Override
public void connectFailed(URI uri, SocketAddress sa, IOException ioe) {}
}
which prints:
"MyProxySelector called with URI = socket://foobar.com:80"
(Note how the protocol has changed from http to socket)
I can of course create my ProxySelector in such a way so that it always returns Proxy.NO_PROXY if the URI scheme is socket but I guess there would be occasions where there's a SOCKS proxy on the site and then it wouldn't be true.
Let me restate the question: I need a way to make sure a specific URLConnection doesn't use a proxy, regardless of what System Properties may be set or what ProxySelector is installed.
This is tracked as JDK bug 8144008.
I'm developing an Android app using Apache Mina for network IO. Non-SSL connections (reading, writing) work fine, but as soon as I add an SSL filter things stop working.
I also tried pure SSL sockets and they work fine.
This is my Mina connection code (in a separate networking thread):
IoConnector connector = new NioSocketConnector();
connector.getSessionConfig().setReadBufferSize(2048);
SocketSessionConfig cfg = (SocketSessionConfig)connector.getSessionConfig();
cfg.setTcpNoDelay(true);
SslContextFactory f = new SslContextFactory();
f.setTrustManagerFactory(new BogusTrustManagerFactory());
f.setProtocol("SSL");
try {
filter = new SslFilter(f.newInstance(), true);
} catch (Exception e) {
Log.d(TAG, "Exception: ", e);
return;
}
filter.setUseClientMode(true);
connector.getFilterChain().addLast("sslFilter", filter);
connector.getFilterChain().addLast("logger", new LoggingFilter());
connector.getFilterChain().addLast("codec", new ProtocolCodecFilter(new TextLineCodecFactory(Charset.forName("ASCII"))));
connector.setHandler(new MinaClientHandler());
ConnectFuture future = connector.connect(new InetSocketAddress("10.0.1.9", 7072));
future.awaitUninterruptibly();
if (!future.isConnected())
{
Log.d(TAG, "not connected, return");
return;
}
IoSession session = future.getSession();
session.getConfig().setUseReadOperation(true);
session.getCloseFuture().awaitUninterruptibly();
//System.out.println(session.read().getMessage());
Log.d(TAG, "after writting");
connector.dispose();
In my IoHandlerAdapter I have the following override:
#Override
public void sessionOpened(IoSession session)
{
session.write(IoBuffer.wrap(data)); // byte array
}
Not my actual code, but it reproduces the problem.
On the server side I see that the connection is accepted an the handshake succeeds. But on the client side nothing is sent over the socket. I have tried the same code in a desktop Java application and it also works.
Also if I move the write call just after IoSession session = future.getSession(); the same thing happens.
Has anyone had similar issues? Are there known issues with Mina on Android? Am I missing some session config options?
Since normal SSL sockets work, that is a workaround, but I would rather not rewrite all my networking code.
In my android application I need to connect to the internet to check for the time. This snippet works very nicely in mobile networks and in WiFi-Networks with no proxy enabled:
public class MyTimeGetterTask {
#Override
protected Long doInBackground(Void... params) {
WebTimeSntpClient client = new WebTimeSntpClient();
if (client.requestTime("time-d.nist.gov", 3000)) {
long now = client.getNtpTime() + SystemClock.elapsedRealtime()
- client.getNtpTimeReference();
return now;
}
else {
return null;
}
}
}
The core elements of the WebTimeSntpClient are as follows:
public class WebTimeSntpClient {
public boolean requestTime(String host, int timeout) {
DatagramSocket socket = null;
try {
socket = new DatagramSocket();
socket.setSoTimeout(timeout);
InetAddress address = InetAddress.getByName(host);
byte[] buffer = new byte[NTP_PACKET_SIZE];
DatagramPacket request = new DatagramPacket(buffer, buffer.length, address, NTP_PORT);
...
socket.send(request);
DatagramPacket response = new DatagramPacket(buffer, buffer.length);
socket.receive(response);
...
} catch (IOException ex) {
return false;
} finally {
if (socket != null) {
socket.close();
}
}
return true;
}
}
However when I'm in the office and the WiFi requires me to configure a proxy (which I did in the settings by long-pressing on the network and then clicking "modify network" - as of Android API level 17) the connection fails.
Now I have looked up quite a lot of very good posts about proxies on the internet and especially here on SO, but absolutely none of them seem to answer this (to me) very simple question:
How do I force my application to use the proxy that is already configured in the settings?
Instead, they focus on more advanced issues like:
How to GET a proxy from the system
How to SET ip information to the system yourself
and much much more about how to make existing applications from the play store use a proxy
Again: I want to stress that this is not my intention, I simply want my app to connect to the internet, no matter what. Is there some System.useWifiProxyIfAvailable(true) method? I'm sure I must have missed a post somewhere here...
You are trying to use SNTP trough a proxy that only allows HTTP/HTTPS.
Your alternative is to use some HTTP service providing the current time, which will be more than enough for most user level applications.
Give http://www.timeapi.org/utc/now a try, however if you are publishing an application using this service you should check the terms and conditions.
I'm working on a WebService Client and I want to set a Timeout for my WebService Call. I have tried different approaches but still I'm not able to achieve this. I'm using JAX-WS for code generation from WSDL. I'm using JBoss-eap-5.1 as App Server and JDK1.6.0_27. I found these diff approaches for setting timeout but none of them is working for me.
URL mbr_service_url = new URL(null,GlobalVars.MemberService_WSDL, new URLStreamHandler() {
#Override
protected URLConnection openConnection(URL url) throws IOException {
URL clone_url = new URL(url.toString());
HttpURLConnection clone_urlconnection = (HttpURLConnection) clone_url.openConnection();
// TimeOut settings
clone_urlconnection.setConnectTimeout(10000);
clone_urlconnection.setReadTimeout(10000);
return (clone_urlconnection);
}
});
MemberService service = new MemberService(mbr_service_url);
MemberPortType soap = service.getMemberPort();
ObjectFactory factory = new ObjectFactory();
MemberEligibilityWithEnrollmentSourceRequest request = factory.createMemberEligibilityWithEnrollmentSourceRequest();
request.setMemberId(GlobalVars.MemberId);
request.setEligibilityDate(value);
((BindingProvider) soap).getRequestContext().put(com.sun.xml.ws.client.BindingProviderProperties.REQUEST_TIMEOUT, 10000);
((BindingProvider) soap).getRequestContext().put(com.sun.xml.ws.client.BindingProviderProperties.CONNECT_TIMEOUT, 10000);
((BindingProvider) soap).getRequestContext().put(com.sun.xml.internal.ws.client.BindingProviderProperties.REQUEST_TIMEOUT, 10000);
((BindingProvider) soap).getRequestContext().put(com.sun.xml.internal.ws.client.BindingProviderProperties.CONNECT_TIMEOUT, 10000);
((BindingProvider) soap).getRequestContext().put(com.sun.xml.ws.developer.JAXWSProperties.REQUEST_TIMEOUT, 10000);
((BindingProvider) soap).getRequestContext().put(com.sun.xml.ws.developer.JAXWSProperties.CONNECT_TIMEOUT, 10000);
((BindingProvider) soap).getRequestContext().put(com.sun.xml.internal.ws.developer.JAXWSProperties.REQUEST_TIMEOUT, 10000);
((BindingProvider) soap).getRequestContext().put(com.sun.xml.internal.ws.developer.JAXWSProperties.CONNECT_TIMEOUT, 10000);
System.setProperty("sun.net.client.defaultConnectTimeout", "10000");
System.setProperty("sun.net.client.defaultReadTimeout", "10000");
MemberEligibilityWithEnrollmentSourceResponse response = soap.getMemberEligibilityWithEnrollmentSource(request);
logger.log("Call to member service finished.");
For now what I have done is, I have called my webservice method from inside an executor. I know its not a good approach, but its working for me. Guys please help me to do it in a proper way.
logger.log("Parameters set for createorUpdateContact call.\nGoing in Executor Service.");
ExecutorService executorService = Executors.newSingleThreadExecutor();
executorService.execute(new Runnable() {
#Override
public void run() {
try {
response = soap.getMemberEligibilityWithEnrollmentSource(request);
} catch (MemberServiceException ex) {
logger.log("Exception in call to WebService", ex.fillInStackTrace());
}
}
});
executorService.shutdown();
try {
executorService.awaitTermination(GlobalVars.WSCallTimeOut, TimeUnit.SECONDS);
} catch (InterruptedException ex) {
logger.log("Thread Interrupted!", ex);
executorService.shutdownNow();
}
You could try these settings (they are paired to be used in pairs)
BindingProviderProperties.REQUEST_TIMEOUT
BindingProviderProperties.CONNECT_TIMEOUT
BindingProviderProperties should be from com.sun.xml.internal.WS.client
Or the strings for JBoss:
javax.xml.ws.client.connectionTimeout
javax.xml.ws.client.receiveTimeout
All properties to be put on getRequestContext() in milliseconds.
(BindingProvider)wsPort).getRequestContext().put(BindingProviderProperties.REQUEST_TIMEOUT, yourTimeoutInMillisec);
For JBoss specifically, you might want to use the property StubExt.PROPERTY_CLIENT_TIMEOUT from org.jboss.ws.core.StubExt. See this thread for details.
Like kolossus said you should use:
com.sun.xml.internal.ws.client.BindingProviderProperties
And String values are:
com.sun.xml.internal.ws.connect.timeout
com.sun.xml.internal.ws.request.timeout
Although internal packages shouldn't be used, this is the only way if you work with default JDK6. So, in this case setting receive and connect timeout should be done with:
bindingProvider.getRequestContext().put(BindingProviderProperties.REQUEST_TIMEOUT,requestTimeoutMs);
bindingProvider.getRequestContext().put(BindingProviderProperties.CONNECT_TIMEOUT,connectTimeoutMs);
But beware, constant values are different if you are using other JAXWS reference implementation, i.e. JAXWS-RT 2.1.4 BindingProviderProperties:
com.sun.xml.ws.client.BindingProviderProperties
you will have different String values for REQUEST_TIMEOUT and CONNECT_TIMEOUT:
com.sun.xml.ws.request.timeout
com.sun.xml.ws.connect.timeout
For me setting javax.xml.ws.client.connectionTimeout and javax.xml.ws.client.receiveTimeout solved the problem.
((BindingProvider)port).getRequestContext().put("javax.xml.ws.client.connectionTimeout", timeout);
((BindingProvider)port).getRequestContext().put("javax.xml.ws.client.receiveTimeout", timeout);
refer link
Setting the following options works for me. I am using the Metro JAXWS implementation.
((BindingProvider)portType).getRequestContext().put(JAXWSProperties.CONNECT_TIMEOUT, 10000);
((BindingProvider) portType).getRequestContext().put(JAXWSProperties.REQUEST_TIMEOUT, 50000);
portType is the Web Service endpoint interface.
Values of the above fields from the com.sun.xml.internal.ws.developer.JAXWSProperties
public static final java.lang.String CONNECT_TIMEOUT = "com.sun.xml.internal.ws.connect.timeout";
public static final java.lang.String REQUEST_TIMEOUT = "com.sun.xml.internal.ws.request.timeout";
Upgrade jbossws-native library and use StubExt.PROPERTY_CLIENT_TIMEOUT
For upgrading jbossws-native, follow this link.
*jbossws-native-3.4.0 is the latest supported version for Jboss 5.1.0GA. You can see JBossWS - Supported Target Containers
This worked for me
I have a old installation runtime that have this environment:
Jdk-1.5, Jboss-4.2.3.GA and the WSClient was created by JAX-WS specification 2.0.
to activate Soap Request Timeout I use the follow code
((BindingProvider)port).getRequestContext().put(org.jboss.ws.core.StubExt.PROPERTY_CLIENT_TIMEOUT, String.valueOf(readTimeout));
and the jar jbossws-client.jar copied in jboss-4.2.3.GA\server\default\lib\
How do you check if you can connect to the internet via java? One way would be:
final URL url = new URL("http://www.google.com");
final URLConnection conn = url.openConnection();
... if we got here, we should have net ...
But is there something more appropriate to perform that task, especially if you need to do consecutive checks very often and a loss of internet connection is highly probable?
You should connect to the place that your actual application needs. Otherwise you're testing whether you have a connection to somewhere irrelevant (Google in this case).
In particular, if you're trying to talk to a web service, and if you're in control of the web service, it would be a good idea to have some sort of cheap "get the status" web method. That way you have a much better idea of whether your "real" call is likely to work.
In other cases, just opening a connection to a port that should be open may be enough - or sending a ping. InetAddress.isReachable may well be an appropriate API for your needs here.
The code you basically provided, plus a call to connect should be sufficient. So yeah, it could be that just Google's not available but some other site you need to contact is on but how likely is that? Also, this code should only execute when you actually fail to access your external resource (in a catch block to try and figure out what the cause of the failure was) so I'd say that if both your external resource of interest and Google are not available chances are you have a net connectivity problem.
private static boolean netIsAvailable() {
try {
final URL url = new URL("http://www.google.com");
final URLConnection conn = url.openConnection();
conn.connect();
conn.getInputStream().close();
return true;
} catch (MalformedURLException e) {
throw new RuntimeException(e);
} catch (IOException e) {
return false;
}
}
People have suggested using INetAddress.isReachable. The problem is that some sites configure their firewalls to block ICMP Ping messages. So a "ping" might fail even though the web service is accessible.
And of course, the reverse is true as well. A host may respond to a ping even though the webserver is down.
And of course, a machine may be unable to connect directly to certain (or all) web servers due to local firewall restrictions.
The fundamental problem is that "can connect to the internet" is an ill-defined question, and this kind of thing is difficult to test without:
information on the user's machine and "local" networking environment, and
information on what the app needs to access.
So generally, the simplest solution is for an app to just try to access whatever it needs to access, and fall back on human intelligence to do the diagnosis.
If you're on java 6 can use NetworkInterface to check for available network interfaces.
I.e. something like this:
Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
while (interfaces.hasMoreElements()) {
NetworkInterface interf = interfaces.nextElement();
if (interf.isUp() && !interf.isLoopback())
return true;
}
Haven't tried it myself, yet.
This code should do the job reliably.
Note that when using the try-with-resources statement we don't need to close the resources.
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.UnknownHostException;
public class InternetAvailabilityChecker
{
public static boolean isInternetAvailable() throws IOException
{
return isHostAvailable("google.com") || isHostAvailable("amazon.com")
|| isHostAvailable("facebook.com")|| isHostAvailable("apple.com");
}
private static boolean isHostAvailable(String hostName) throws IOException
{
try(Socket socket = new Socket())
{
int port = 80;
InetSocketAddress socketAddress = new InetSocketAddress(hostName, port);
socket.connect(socketAddress, 3000);
return true;
}
catch(UnknownHostException unknownHost)
{
return false;
}
}
}
This code:
"127.0.0.1".equals(InetAddress.getLocalHost().getHostAddress().toString());
Returns - to me - true if offline, and false, otherwise. (well, I don't know if this true to all computers).
This works much faster than the other approaches, up here.
EDIT: I found this only working, if the "flip switch" (on a laptop), or some other system-defined option, for the internet connection, is off. That's, the system itself knows not to look for any IP addresses.
InetAddress.isReachable sometime return false if internet connection exist.
An alternative method to check internet availability in java is : This function make a real ICMP ECHO ping.
public static boolean isReachableByPing(String host) {
try{
String cmd = "";
if(System.getProperty("os.name").startsWith("Windows")) {
// For Windows
cmd = "ping -n 1 " + host;
} else {
// For Linux and OSX
cmd = "ping -c 1 " + host;
}
Process myProcess = Runtime.getRuntime().exec(cmd);
myProcess.waitFor();
if(myProcess.exitValue() == 0) {
return true;
} else {
return false;
}
} catch( Exception e ) {
e.printStackTrace();
return false;
}
}
I usually break it down into three steps.
I first see if I can resolve the domain name to an IP address.
I then try to connect via TCP (port 80 and/or 443) and close gracefully.
Finally, I'll issue an HTTP request and check for a 200 response back.
If it fails at any point, I provide the appropriate error message to the user.
URL url=new URL("http://[any domain]");
URLConnection con=url.openConnection();
/*now errors WILL arise here, i hav tried myself and it always shows "connected" so we'll open an InputStream on the connection, this way we know for sure that we're connected to d internet */
/* Get input stream */
con.getInputStream();
Put the above statements in try catch blocks and if an exception in caught means that there's no internet connection established. :-)
The code using NetworkInterface to wait for the network worked for me until I switched from fixed network address to DHCP. A slight enhancement makes it work also with DHCP:
Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
while (interfaces.hasMoreElements()) {
NetworkInterface interf = interfaces.nextElement();
if (interf.isUp() && !interf.isLoopback()) {
List<InterfaceAddress> adrs = interf.getInterfaceAddresses();
for (Iterator<InterfaceAddress> iter = adrs.iterator(); iter.hasNext();) {
InterfaceAddress adr = iter.next();
InetAddress inadr = adr.getAddress();
if (inadr instanceof Inet4Address) return true;
}
}
}
This works for Java 7 in openSuse 13.1 for IPv4 network. The problem with the original code is that although the interface was up after resuming from suspend, an IPv4 network address was not yet assigned. After waiting for this assignment, the program can connect to servers. But I have no idea what to do in case of IPv6.
1) Figure out where your application needs to be connecting to.
2) Set up a worker process to check InetAddress.isReachable to monitor the connection to that address.
This code is contained within a jUnit test class I use to test if a connection is available. I always receive a connection, but if you check the content length it should be -1 if not known :
try {
URL url = new URL("http://www.google.com");
URLConnection connection = url.openConnection();
if(connection.getContentLength() == -1){
fail("Failed to verify connection");
}
}
catch (IOException e) {
fail("Failed to open a connection");
e.printStackTrace();
}
public boolean checkInternetConnection()
{
boolean status = false;
Socket sock = new Socket();
InetSocketAddress address = new InetSocketAddress("www.google.com", 80);
try
{
sock.connect(address, 3000);
if(sock.isConnected()) status = true;
}
catch(Exception e)
{
status = false;
}
finally
{
try
{
sock.close();
}
catch(Exception e){}
}
return status;
}
You can simply write like this
import java.net.InetAddress;
import java.net.UnknownHostException;
public class Main {
private static final String HOST = "localhost";
public static void main(String[] args) throws UnknownHostException {
boolean isConnected = !HOST.equals(InetAddress.getLocalHost().getHostAddress().toString());
if (isConnected) System.out.println("Connected");
else System.out.println("Not connected");
}
}
There are (nowadays) APIs for this, but they are platform specific:
On Android ConnectivityManager (https://developer.android.com/training/basics/network-ops/reading-network-state) does everything you need.
On Windows INetworkListManager::GetConnectivity (for which you'll need a JNI)
On generic Linux, you are probably stuck with testing if you have access to a DNS server and Google, as above.
there is probably an Apple way to do this as well
(I'd use the specific tools where available)
This have worked well for me.
try{
InetAddress addr = InetAddress.getByName("google.com" );
}catch(IOException e){
JOptionPane.showMessageDialog(new JFrame(),"No Internet connection.\nTry again later", "Network Error", JOptionPane.ERROR_MESSAGE);
}
There is also a gradle option --offline which maybe results in the behavior you want.
The following piece of code allows us to get the status of the network on our Android device
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView mtv=findViewById(R.id.textv);
ConnectivityManager connectivityManager=
(ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if(((Network)connectivityManager.getActiveNetwork())!=null)
mtv.setText("true");
else
mtv.setText("fasle");
}
}
}