I am using the Restlet Framework, but now I want to change to a proper server instead of using localhost.
I have already added my php files (they access the java files using the rest_server URL) to the server's folder and my java files as well, but I am not sure how to change the code so it identifies where the new location of the files is.
Here is the code from IdentiscopeServer (constructor empty):
public static void main(String[] args) throws Exception {
//setsup our security manager
if (System.getSecurityManager() == null){
System.setSecurityManager(new SecurityManager());
}
identiscopeServerApp = new IdentiscopeServerApplication();
IdentiscopeServer server = new IdentiscopeServer();
server.getServers().add(Protocol.HTTP,8888);
server.getDefaultHost().attach("", identiscopeServerApp);
server.start();
}
I guess that the correct line to change is the one with "Protocol.HTTP, 8888". If the address of my new server is http://devweb2013.co.uk/research/Identiscope, how exactly do I set this up? Is there anything else necessary for it to work apart from just moving the files to a folder in the server?
The IdensticopeServerApplication is the following:
public class IdentiscopeServerApplication extends Application {
public IdentiscopeServerApplication() {
}
public Restlet createInboundRoot() {
Router router = new Router(getContext());
//attaches the /tweet path to the TweetRest class
router.attach("/collectionPublic", CollectionPublicREST.class);
router.attach("/collectionPrivate", CollectionPrivateREST.class);
router.attach("/analysis", AnalysisREST.class);
return router;
}
}
Thank you in advance, it is my first time using this Framework.
If I understand you correctly, you just want to run your main() method as the server, correct? In this case, the code for main() needs to be in a location that -- when running -- can provide the service at http://devweb2013.co.uk/research/Identiscope. Since you haven't stated what kind of server you are putting the code, I can't say where the best place to put the code would be. I assume you have superuser privileges on your deployment server, since the URL you provided implies port 80 will be serving your Identiscope web service (port 80 is a privileged port on most OS's). So as an answer, I can only provide general information.
On your deployment server, port 80 must be free (i.e. nothing else should be acting as a web server on port 80 on that machine) and the IdentiscopeApplication must be running on port 80. To do that, you need only change the line:
server.getServers().add(Protocol.HTTP,8888);
to:
server.getServers().add(Protocol.HTTP, 80);
then run the application as a user that is allowed to start servers on port 80 (preferably NOT the superuser). If you haven't already, you will need to get Java running on your deployment server and make sure all Restlet libraries are in the classpath where you plan to run your application.
If I understand what you are trying to do, then this should do the trick.
Related
I have a Android application which consumes a webservice on a local network. There's a config screen where the user inform the server IP address, which is running Apache Tomcat.
I'm looking for a way to auto-detect the server based on the current connected wi-fi network.
i.e: The smartphone's IP is 10.1.1.90 and the server IP is 10.1.1.254.
Is there a way to achieve this? I'm thinking on using ping, but I don't know if is a good ideia.
The way I understand it, you need to discover IP of your tomcat server and connect it using your client.
I am assuming , both the server and client is in your control.
One simple way can be to use jGroups Cluster.
You can make your tomcat discoverable
Client can discover it using the name of the cluster you have provided .Refer the JChannel API that Jgroups uses
I simulated it making following server class
public class TomcatServer {
JChannel channel;
private void start() throws Exception {
channel = new JChannel(); // use the default config, udp.xml
channel.connect("TomcatCluster");
}
public static void main(String[] args) throws Exception {
new TomcatServer().start();
}
}
The simulated client class
public class MobileApp extends ReceiverAdapter {
JChannel channel;
private void start() throws Exception {
channel = new JChannel(); // use the default config, udp.xml
channel.setReceiver(this);
channel.connect("TomcatCluster");
channel.close();
}
public static void main(String args[]) throws Exception {
new MobileApp().start();
}
The client will provide you following information
GMS: address=MACHINENAME-47879, cluster=TomcatCluster, physical address=xxxxx:0:xxx:xxxx:xxxx:xxxx:xxx:xxxx:xxxx
** view: [MACHINENAME-31239|1] [MACHINENAME-31239, MACHINENAME-47879]
Where MACHINENAME-47879 is the client machine and port & MACHINENAME-31239 is the tomcat server name and port
Do you want to detect "a tomcat server" or "your tomcat server" ?
I mean, do you have any way to custom your server ? If it's the case, then you could create a very simple test page on your server (say a "Hello" JSP page), which your Android application could look for.
If your Android gets a "Hello" result with a GET request on http://<tomcat_ip>/hello.jsp, then you may assume that the tomcat is online.
If you can't add this test page, then you can test any page which the server is supposed to serve. (even a 404 page which sometimes is not configured well, and shows the tomcat version...)
Tomcat response headers can contain the xpoweredBy field that would advertise Tomcat if enabled. However it is most often disabled due security considerations, and even disabled by default. You however could re-enable it if you need to auto-detect exactly your Tomcat servers. From the other side, indeed, if you can place a web page on your server, you can simply place a marking page with the agreed signature.
If the server IP is unknown, I would propose the following ways to detect the server on the network:
The most straightforward way is to do the breadcast ping (ping -b broadcast_address where breadcast address can be computed here, for instance). All network devices that are configured so would reply, then verify as explained above which one is the server. However pinging broadcast address requires a rooted phone. Also the router may not support.
Your DHCP service (most likely your router) can often be configured to issue always the same IP address for the same MAC address of your server network card.
If the server is a desktop computer or laptop, it could show its address as QR code on display. It is possible for a smartphone to scan the code from the screen, and this is way easier than to enter IP address through the touchscreen. QR code can also include auto-generated password for extra security.
If there is wireless router with the possible login where both server and client are connected, the internal pages of that router often contain the relevant IP addresses. You would need to implement logging into the router and doing some screen scrapping.
I made an Android app which used a local server in the WLAN. I made the terminal (the phone) broadcast it's own IP address, which the server then picked up.
I used MultiCast class on the phone, which added the ip-address of itself to the payload. The server always has a thread in multicast read class that obains the payload of the packet (which is the terminals ip-address). Set the terminal in datagram read state and send the servers ip-address to terminal.
Maybe are better ways, but a great way to get the ip-addresses of unknown terminals in the network.
The way i had resolved this problem is with the use of enumerations.
public String getLocalIpAddress()
{
try {
for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();) {
NetworkInterface intf = en.nextElement();
for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements();) {
InetAddress inetAddress = enumIpAddr.nextElement();
if (!inetAddress.isLoopbackAddress()) {
return inetAddress.getHostAddress().toString();
}
}
}
} catch (Exception ex) {
}
return null;
}
}
I have been working on this project where two modules on different machines need to be in communication through RMI.
I start both client and server modules on my laptop. RMI seems to work correctly when i am at work and connected to work network, but when i am home, connected to my home network it does not work. It says remote object could not be found.
Here is the method i use at CLIENT side to get the reference to remote object
public static MyRMIApp getRemoteApp() throws RemoteException, NotBoundException, AccessException {
Registry registry = LocateRegistry.getRegistry("localhost", 28999); // tried 127.0.0.1 instead of localhost here, still not working
MyRMIApp app = (MyRMIApp) registry.lookup("COM");
return app;
}
Digging up a bit with some debugging, when i check the object value returned from getRemoteApp method, it shows me the end point is 67.215.65.132. Which is openDNS i am using to connect to internet. Shouldn't that be 127.0.0.1 ?
Then i used my mobile internet and tried again. It seems to be working but end-point is not 127.0.0.1 again it is the address assigned to me, which is 192.168.x.x
So can anybody please tell me what is wrong i am doing here ? I really would appreciate the help.
Oh and this is the piece of code at SERVER side
//Somwhere up top
private final static MyRMIApp rmiApp = new RMIServer();
//Down below
MyRMIApp stub = (MyRMIApp) UnicastRemoteObject.exportObject(rmiApp, 0);
Registry registry = LocateRegistry.createRegistry(28999);
registry.rebind("COM", stub);
See item A.1 of the RMI FAQ: specifically, 'The appropriate workaround is to set the system property java.rmi.server.hostname when starting the server.'
I have a desktop application built with jdk 6 which publishes web services to be consumed by a web application. So far I've had no problem while both applications are running in the same physical computer, i can access the wsdl without any problem and the web application works with the desktop application just fine. The thing is I cannot access to the services from a remote computer in the same network. The two PCs are connected and can interact. If I run both applications in PC1, from PC2 I can use the webapp through
http://PC1:8080
I am currently publishing like this:
public Publicador(){
servicios= new Servicios();
Endpoint endpoint = Endpoint.publish("http://PC1:8686/servicios", servicios);
}
where PC1 is the name of the pc. From PC1, i can see the generated wsdl from the following address, and it's the one I used for the wsimport command:
http://PC1:8686/servicios?wsdl
But I cannnot from PC2.
Any ideas why it is not visible from outside PC1?
Incredible as it may seem, I found the simplest of answers... Instead of publishing as
Endpoint endpoint = Endpoint.publish("http://PC1:8686/servicios", servicios);
I published as
Endpoint endpoint = Endpoint.publish("http://0.0.0.0:8686/servicios", servicios);
and that solved it...
Another solution was to get the address to publish from a file, that worked too. I don't know why it didn't hardcoded... I ended up doing it like this:
Properties prop = new Properties();
InputStream is = null;
String currenDir = System.getProperty("user.dir");
String nombreArchivo = currenDir + File.separator + "ubicacion.PROPERTIES";
try {
is=new FileInputStream(nombreArchivo);
prop.load(is);
} catch(IOException ioe) {}
String pc = prop.getProperty("ServiciosWeb");
Endpoint endpoint = Endpoint.publish( pc, servicios);
}
I'm looking form way how to get system proxy information in Java under Windows, but I've found just one way. But it does not work for me.
public static void main(String[] args) throws Throwable {
System.setProperty("java.net.useSystemProxies", "true");
System.out.println("detecting proxies");
List<Proxy> pl = ProxySelector.getDefault().select(new URI("http://ihned.cz/"));
for (Proxy p : pl)
System.out.println(p);
Proxy p = null;
if (pl.size() > 0) //uses first one
p = pl.get(0);
System.out.println(p.address());
System.out.println("Done");
}
When I run the program, I get:
detecting proxies
DIRECT
null
Done
Java means, that I'm situated directly on internet. But it's wrong. I'm behind proxy. I'm unable to get the solution for my computer.
As we discussed in the comments the proxy settings is just applied for some of browsers you use.
If you want Java to use the same settings you need to manually put it into the java network settings (check this web page for details).
Thanks to Dacwe. The problem is, that browser does not use any system proxy, but it sets proxy self using a script. Thus there are not any proxies in the system and Java cannot reach them.
Tomcat offers a build in "Virtual Hosting" Support: An Engine/Web-Application can be configured to be responsible for a list of Domains. These Domains have to be put into the server.xml/context.xml files with a special xml directive.
=> Is there any possibility to change the Tomcat Configuration (in general) and especially the "Virtual Hosts" of a Web-Application/Engine programmatically?
For example if a new user signs up, I have to add his domain to the list of "accepted virtual hosts/domains". The only way I currently think of is changing the xml files via a script and then restart Tomcat.
Is there any way to add them add runtime via some Java-Methods programmatically?
Thank you very much!
Jan
Tomcat provides APIs to create new virtual host. To get access to the wrapper object needed for this, you need to implement a ContainerServlet. You can create virtual host like this,
Context context = (Context) wrapper.getParent();
Host currentHost = (Host) context.getParent();
Engine engine = (Engine) currentHost.getParent();
StandardHost host = new StandardHost();
host.setAppBase(appBase);
host.setName(domainName);
engine.addChild(host);
You need to make sure appBase directory exist and you have to find ways to persist the new host to the server.xml or you lose the host on restart.
However, this approach rarely works. If your users run their own apps, you really want run separate instances of Tomcat so you can sandbox the apps better. e.g. One app running out of memory doesn't kill all other apps.
If you provide the app, you can just use one host (defaultHost). You can get the domain name from Host header and do whatever domain-specific stuff in your code.
You shouldn't change the server environment programmatically and there are no reliable and standard ways to do this. Best is to do and keep it all on the webapp side. To start, a Filter is perfectly suitable for this. Store the names somewhere in a database table or a properties file which you cache in the application scope. Check the HttpServletRequest#getRequestURI() (or the getServerName() if it is a subdomain instead of pathinfo) and do the forwarding task accordingly.
Hope this helps.
Use JMX
ArrayList serverList = MBeanServerFactory.findMBeanServer(null);
MBeanServer server = (MBeanServer) serverList.get(0);
Object[] params = { "org.apache.catalina.core.StandardHost", hostName };
String[] signature = { "java.lang.String", "java.lang.String" };
server.invoke(new ObjectName("Catalina:type=Engine"), "addChild", params, signature);
If needed, retrieve the host object and work with it:
ObjectName host = new ObjectName("Catalina:type=Host,host=" + hostName);
server.setAttribute(host, new Attribute("autoDeploy", false));
server.invoke(host, "start", null, null);
I would suggest you set your application to be the default virtual host in server.xml so your single virtual host can respond to requests addressed to any host name. Tomcat ships with the localhost application set as the default virtual host. So you can see how to do this by simply inspecting the server.xml file of a vanilla tomcat installation. You can programatically determine the host name the user sent the request to using the ServletRequest.getServerName() method.
Tomcat used to ship with a web application called "host-manager". Note: this is different than the "manager" web application that still comes with Tomcat. Host manager allowed for changing configuration or adding new virtual hosts on the fly without restarting the server. You could interact with the host-manager over HTTP (programmatically if desired). However, it had the unfortunate flaw of not committing its changes to server.xml so they were all lost on a web server restart. For whatever reason, starting with version 6, Tomcat no longer ships with the host-manager application. So it doesn't appear to be supported anymore.
To sum up ZZ Coder answer which guided me a lot:
You have to create a servlet that implements ContainerServlet and override setWrapper method to get the org.apache.catalina.Wrapper object.
For doing that you have to have privileged="true" in your context.xml Context tag or it will throw an exception. Then you can use the Wrapper object and:
StandardContext context = (StandardContext) wrapper.getParent();
StandardHost currentHost = (StandardHost) context.getParent();
StandardEngine engine = (StandardEngine) currentHost.getParent();
StandardHost host = new StandardHost();
host.setAppBase(currentHost.getAppBase()); //in my case I created another instance of the same application
host.setDomain(currentHost.getDomain());
host.setAutoDeploy(false); // not restarting app whenever changes happen
host.setName("domain.com");
host.setThrowOnFailure(true);// tell it to throw an exception here if it fails to create the host
host.setDeployOnStartup(true);
host.setStartChildren(true);
host.setParent(engine);
// you can add multiple aliases
host.addAlias(alias);
StandardContext ctx = new StandardContext();
ctx.setDocBase(context.getDocBase()); //again I reused my same application setting
ctx.setPath("");
if(currentHost.getWorkDir() != null)
{//create a working directory based on your new host's name
ctx.setWorkDir(currentHost.getWorkDir().replace(currentHost.getName(), host.getName()));
}
ctx.setName(host.getDomain());
//some extra config that you can use
ctx.setUseHttpOnly(false);
ctx.setReloadable(false);
ctx.setXmlValidation(false);
ctx.setXmlNamespaceAware(false);
ctx.setCrossContext(false);
ctx.setParent(host);
// you have to have this or it will not work!!
ctx.addLifecycleListener(new ContextConfig());
//you can also create resources and add it to the context like so:
final ContextResource res = new ContextResource();
res.setName("name");
res.setAuth("Container");
res.setType("javax.sql.DataSource");
ctx.getNamingResources().addResource(res);
host.addChild(ctx);
engine.addChild(host);
You can add properties to your resource by calling res.setProperty("name", "value")
Some properties that you can use are:
initialSize,maxTotal,maxIdle,maxWaitMillis,removeAbandonedOnBorrow,removeAbandonedTimeout,validationQuery,timeBetweenEvictionRunsMillis,driverClassName,url,username,password.
Another exciting thing to is to get the host from the tomcat engine by calling engine.findChild(domain) and use stop(), start(), getStateName() and have your own Tomcat Admin panel!