Develop Reference

cannot use both TOMCAT server and my internet connection

I cannot have my tomcat server started and at the same time use internet.
either I can start Tomcat (in Eclipse) and internet is not available.
or I can access the internet but tomcat cannot be started.
Here the original probleme I had when I first wanted to use Tomcat and display my html page on localhost.
GRAVE: StandardServer.await: create[localhost:8005]: I find a way to start the Tomcat Server: in the terminal:
sudo lsof -i : 8005 # checks port 80
sudo route -n flush
sudo route add default 192.168.1.1
then I can use tomcat and localhost:8080 but my internet connexion is dead
if I want my internet connexion then I stop the tomcat server by clicking on the red square in eclipse and then in the terminal I do:
sudo route -n flush
sudo route add default 192.168.0.1
THen I can use internet but tomcat cannot be restarted. I have to undergo the first process.
this of course is a very boring process and I would like to know what 's wrong and how I could fix it.
I use tomcat 9 / Mac OS sierra / Eclipse Neon3

When you say "my internet connexion is dead", do you mean that your network connection drops or that your DNS lookups fail? (What do you think this command is doing and why are you performing it: sudo route add default 192.168.1.1?)
If your program is modifying your system's connectivity settings, I would strongly recommend against preventing it from doing that. There's no reason for it to do so at that level, a more appropriate place to set settings would be at some deploy stage.
Alternatively, you could run your app in a Docker container which I strongly suspect will solve your problem. Visit www.docker.com to learn more.

Connect JVisualVM to a Remote Wildfly Instance?

I'm trying to connect JVisualVM, running on my local machine, to a remote machine which is running a WildFly server (version 8.1.0, to be specific.)
I didn't configure the WildFly server myself, and I don't know who did, but I do know that I can log in as an administrative user from my local machine by pointing my browser at:
https://[ip address of the remote machine]:9443/console
Note that it's https, not ordinary http, and that the port for that has been set to 9443 (I think the default is 8080 or 9990 or something... IDK, I saw a lot of port numbers online. I have been explicitly told that http was disabled for this WildFly server).
I can SSH into the remote machine. I can navigate to the bin directory for WildFly and run jboss-client.sh. I have to connect on port 9999 (I think the default is 9990 for that?)
I copied the jboss-client.jar (under bin/client) to my local machine and ran JVisualVM from the command line like this:
.\jvisualvm.exe -cp:a C:\[path to]\jboss-client.jar
It launches fine. File > Add Remote Host: Then I entered the IP. OK. I right clicked on it under Remote in the tree and picked Add JMX Connection. I entered
service:jmx:http-remoting-jmx://[ip]:9999
I checked off that I wanted to use the security credentials and entered the username and password. Checked off to save the security credentials. Left "Do not require SSL Connection" unchecked. Hit OK. It immediately spat out the message
Cannot connect to admin#service:jmx:http-remoting-jmx://[ip]:9999 using service:jmx:http-remoting-jmx://[ip]:9999
I also tried the port 9443, 9990, and 8080 instead. None of those worked. I tried https instead of http in the protocol name. That also didn't work.
What am I missing? How is it that I can access the console, and connect with jboss-client.sh, but I can't use JVisualVM? Is there some log I can use somewhere to see what's wrong? Maybe someone can point out a configuration I've missed somewhere?
Not sure if it's important or not, but my local machine is running Windows 10 with JDK8 installed. The WildFly server is using Java 6 on CentOS 6.3.

You need to add the jboss-client.jar (or jboss-cli-client.jar) to the class path for JVisualVM. The library can be found in the bin/client directory of the WildFly install.
I used the following command to add the library to the class path.
jvisualvm --cp:a ~/servers/wildfly-10.0.0.Final/bin/client/jboss-client.jar
Then I used service:jmx:remote+http://[ip]:[port] and was able to connect.

I don't know if someone else is also (still) having the same issue (Wildfly10 on a remote machine where management console is available at 9443 with HTTPS). The following worked for me.
For ssh connections:
Starting jvisualvm with jboss-client.jar
jvisualvm --cp:a #JBOSS_HOME/bin/client/jboss-client.jar
Using the following connection string:
service:jmx:remote+https://remote-server:9443
NOTE: I used here remote+https
Provide username and password
Hope this helps.

you missed run jstatd command in remote host ,
this little program is RMI server that possible connection from client to remote host though you using jmx connection it used jmxrmi protocol for that connection .
so first in remote host create file name as security.policy with this contain :
grant codebase "file:${java.home}/../lib/tools.jar" {
permission java.security.AllPermission;
};
off course you must in file section for linux put explicit path and then of creation this file put it in bin directory of jdk.home
then you should run this command on remote host
$JAVA_HOME/bin/jstatd -J-Djava.security.policy=path of /security.policy -J-Djava.rmi.server.hostname=remote ip address -J-Djava.net.preferIPv4Stack=true
then you could connect to server off course with correct settings.

Include jboss-cli-client.jar and jboss-client.jar under \lib\visualvm\platform\lib and restart jvisualvm to pickup new jars.

tomcat 7 change localhost to ip address/hostname

I have deployed tomcat 7 on unix server. Application is working properly in its internal text mode browser which is elinks.
My server ip is 190.0.0.1 and hostname is test123. In elink i entered the URL http://localhost:9999/Test, then the application is working properly.
But whenever i tried to access the application hitting URL http://190.0.0.1:9999/Test, than it is not working. I checked the logs there is no error message in it.
May be some configuration issue i have to change but dont know which?

Please issue hostname -i in your unix box to get the ip address of your machine. Example:
[ssivan#wsapp403p.prod.ch4 conf]$ hostname -i
10.236.55.42
Then you can try with that ip address. Example:
http://10.236.55.42:9999/Test

jboss-5.1.0.GA startup issue

I am trying to configure jboss-5.1.0.GA server for my application on linux platform. When I am starting the server I can see in the log that it starts successfully, but when I am trying to access the started port(8080 by default) it shows no response from server as if server not started. Can any one please help me to sort out this thing.

these are just reasonable guesses, but try the following:
start your server on a commandline with following option:
-b 0.0.0.0
try following options to check if your server is running:
http://127.0.0.1:8080/
http://localhost:8080/
http://(your ip):8080/
good luck

How to remote connect to linux/WASv7 with JConsole?

I'm trying to remotely connect to a server with JConsole to monitor & make use of the MBeans registered there.
I can VNC onto the server and run JConsole locally with "localhost:8050", but any attempt to connect remotely, via ip address or hostname, fails in a NullPointerException.
java.lang.NullPointerException
at
javax.management.remote.rmi.RMIConnector.connect(RMIConnector.java:281)
at
javax.management.remote.rmi.RMIConnector.connect(RMIConnector.java:227)
at sun.tools.jconsole.ProxyClient.tryConnect(ProxyClient.java:334)
at sun.tools.jconsole.ProxyClient.connect(ProxyClient.java:296)
at sun.tools.jconsole.VMPanel$2.run(VMPanel.java:280)
I've read through the other excellent q&a's here and on many other websites. I've tried opening ports with iptables, editing the hosts file. ssl and authentication are disabled, local.only is disabled. I've disabled the proxy and tried the JMXServiceURL too, to no avail.
How come i am able to run JConsole & connect locally but not remotely?
I even have a second server, running win2008 & tomcat, that plays along perfectly!
Any ideas?
Thanks!
Martin

JAVA_OPTS="-Dcom.sun.management.jmxremote \
-Dcom.sun.management.jmxremote.port=<port no> \
-Dcom.sun.management.jmxremote.ssl=false \
-Dcom.sun.management.jmxremote.authenticate=false \
-Dcom.sun.management.jmxremote.local.only=false \
-Djava.rmi.server.hostname=<server ip>"
Try to use this setting on your application server. It worked for me on Tomcat.