Remote debugging on Tomcat with Eclipse - java

I'm trying to initiate a remote debugging session on my PC with Eclipse & Tomcat.
I managed to run tomcat (not through eclipse) with the following params:
set JPDA_TRANSPORT=dt_socket
set JPDA_ADDRESS=5050
cataline jpda start
The server starts ok, this is the outcome:
Using CATALINA_BASE: "C:\Java\Tomcat"
Using CATALINA_HOME: "C:\Java\Tomcat"
Using CATALINA_TMPDIR: "C:\Java\Tomcat\temp"
Using JRE_HOME: "C:\Java\jdk1.6.0_27"
Using CLASSPATH: ...
Listening for transport dt_socket at address: 5050
...
...
INFO: Server startup in 12502 ms
Now, I opened eclipse, and loaded the relevant project.
I set a new debugging configuration using Remote Java Application with localhost and the right port. however when I run it, I get this error message:
Failed to connect to remote VM. Connection refused.
Connection refused: connect
Can't really understand where is the problem. this is all local inside the PC, so there shouldn't be any firewalls involved, can someone think of something ?

Found the solution. apparently the connection was made, but Eclipse & Tomcat don'tt show any notification or status regarding it.
Then, when you initiate the connection again, you get the error because you're already connected.
I think that a small notice, either from Eclipse, or from Tomcat would be nice.

Try adding the following debug options directly to the JVM startup by directly modifying the catalina startup script
-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=5050

There could be problems when there are code mismatches between eclipse and tomcat. So when it matches the error will disappear

You can configure it in remote java application section in debug configuration.
For more details you can refer this link

Related

Spring Boot with debug args not close debug port after application stopped

I'm running my Spring Boot application with debug mode enabled. Like:
mvn -P dev spring-boot:run -Drun.jvmArguments="-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=5005"
I can debug the application after that without any problem. But, after stopped (ctrl + c) and try to start again, I receive this error:
[INFO] Attaching agents: []
ERROR: transport error 202: bind failed: Address already in use
ERROR: JDWP Transport dt_socket failed to initialize, TRANSPORT_INIT(510)
JDWP exit error AGENT_ERROR_TRANSPORT_INIT(197): No transports initialized [debugInit.c:750]
So, every time that I need to start the application in debug mode after that, I need to kill the process using the port 5005.
I would like to know why the port 5005 is still opened after stop the application.
I'm using Cygwin64 on Windows 10, Maven 3.5.2, Java 8 and Spring Boot 1.5.9.RELEASE.
Thanks!
This is not a problem of Spring Boot, but a problem of non-cygwin applications running in cygwin. And your application is not only leaving port 5005 open, it just keeps running in the background, having port 8080 also opened, but as on a restart the debug port is first opened, this is what you see in the error message.
This was discussed in a SpringBoot issue back in 2014 https://github.com/spring-projects/spring-boot/issues/773. I cite from this issue (the link in the citation dates from 2006):
Anyone still following this bug, this isn't a Spring Boot bug at all. It's a known problem with non-Cygwin programs (Java in this case) running on pty-based terminals.
See this link for a full explanation why this can't be fixed: http://cygwin.com/ml/cygwin/2006-12/msg00151.html
So you can basically use one of the following approaches:
use the native windows terminal and setup your java and maven environment for that
run your maven command from within an IDE which can handle this - you might use this for debugging as well
add the Spring Actuator to your app and use the /shutdown endpoint to stop your application

Tomcat home page is not coming properly

After installing Apache tomcat8 I am getting below home page.
I just installed tomcat8, start service and hit url
http://localhost:8080/
I haven't created any project.
It looks to me that the page in your screenshot is being served up by Oracle Application Express (APEX), not Tomcat.
APEX typically uses port 8080, and if you started this before starting Tomcat, Tomcat will be unable to use port 8080. To confirm that this is the case, take a look in your Tomcat stderr log file (it should be under C:\Tomcat 8.0\logs and have a name like tomcat8-stderr.2014-09-21.log). It will quite probably contain an exception whose stacktrace begins as follows:
21-Sep-2014 12:09:15.607 SEVERE [main] org.apache.coyote.AbstractProtocol.init Failed to initialize end point associated with ProtocolHandler ["http-nio-8080"]
java.net.BindException: Address already in use: bind
at sun.nio.ch.Net.bind0(Native Method)
I would recommend that you change Tomcat to use another port. To do this, open your server.xml file (in C:\Tomcat 8.0\conf\). There should be a Connector element in here with an attribute port="8080": change this port number to 8081 (say) and restart Tomcat.
Ok, try this
1- Download a tomcat version.
2- unzip it in a folder. (let say C:\Java)
3- open a command prompt window
4- Type C:\Java\ your tomcat installation \bin\startup.bat
5- Access http://localhost:8080
Looks like you have not started tomcat yet.
Are you sure you have followed a guide like this ?

"Uncaught Could not connect" error when using Openshift to deploy .war for PHP/Java bridge

Problem: Recieve 'Could not connect' error when using Openshift to deploy .war for PHP/Java bridge
Below I describe every step I've taken to get to this error, thanks in advance.
Full error: (IP concealed)
"Fatal error: Uncaught Could not connect to the JEE server W.X.Y.Z:8080. Please start it. Or define('JAVA_HOSTS',9267); define('JAVA_SERVLET',false); before including 'Java.inc' and try again. Error message: Connection refused (111) thrown in /home/stevenw1/public_html/softwareProject/real/inc/Java.inc on line 989"
Players: "Java_Bridge.war" = my java .war file that php will use to call methods from
"W.X.Y.Z" = Unchanging IP address of deployed .war file
"GUIProfile" = a Java class with #WebServlet("/GUIProfile") as public class GUIProfile extends HttpServlet
"tomcattest.php" = test file that calls GUIProfile's static method 'validate'
Deployed Java_Bridge.war and tomcattest.php work fine on my local tomcat, just not yet on Openshift.
Senario:
0. followed command line steps from Openshift 2012 java tomcat application
1. Using Openshift's rhc I have created my first app using "rhc app create -a tomcat6 -t jbossews-1.0"
2. cd ~/tomcat6/; git rm -rf ./src/ pom.xml
3. cp ~/Java_Bridge.war ./webapps/; git add ./webapps/Java_Bridge.war; git commit -m "first try"; git push
//notable output includes:
remote: Stopping jbossews cartridge
remote: Sending SIGTERM to jboss:386662 ...
remote: Skipping Maven build due to absence of pom.xml
remote: Preparing build for deployment
remote: Deployment id is bd83d6eb
remote: Activating deployment
remote: + '[' Java_Bridge.war ']'
remote: Starting jbossews cartridge
remote: Found W.X.Y.Z:8080 listening port //(not actual IP)
remote: Git Post-Receive Result: success
remote: Activation status: success
remote: Deployment completed with status: success
to ssh://thisisnottheactualuser#tomcat6-notthenamehereeither.rhcloud.com
4. Thinking the .war was deployed I ran a tomcattest.php that calls a java method 'validate', from java class GUIProfile that extends httpservlet, using the php/java bridge Java.inc
//of course using the same IP from above...
cat tomcattest.php;
<?php
define("JAVA_HOSTS", "W.X.Y.Z:8080");
define("JAVA_SERVLET", "/Java_Bridge/GUIProfile");
require_once("Java.inc");
$valiationOutput = java_context()->getServlet()->validate("hello");
echo $valiationOutput;
?>
EDIT: later tried this also in all instances: same results exactly
cat alternatetest.php
<?php
define("JAVA_HOSTS", "W.X.Y.Z:8080");
require_once("Java.inc");
echo java("java.lang.System")->getProperties();
?>
The output of calling tomcattest.php is the 'Fatal error' you see at the top.
Double Check:
5. ssh thisisnottheactualuser#tomcat6-notthenamehereeither.rhcloud.com
6. env | grep "IP"
OPENSHIFT_JBOSSEWS_IP=W.X.Y.Z
7. env | grep "PORT"
OPENSHIFT_JBOSSEWS_HTTP_PORT=8080
OPENSHIFT_JBOSSEWS_JPDA_PORT=8787
8. changed port in tomcattest.php to 8787, didn't change a thing of course.
9. restarted from the top, this time keeping ./src/ & pom.xml, same 'Deployment completed with status: success', same error using tomcattest.php with new listening IP...
10. tried solution from 'openshift youtube vid 2012' seemingly outdated. Followed step by step:
onced ssh'ed, no "tomcat" dir, I used cd $OPENSHIFT_DATA_DIR instead to access data dir
wget tomcat, changed ports to >15000, sh startup.sh && tail -f ../logs/*
notable errors in the result include:
SEVERE: Failed to initialize connector [Connector[AJP/1.3-15009]]
org.apache.catalina.LifecycleException: Failed to initialize component
[Connector[AJP/1.3-15009]] SEVERE: Failed to initialize connector
[Connector[AJP/1.3-15009]] org.apache.catalina.LifecycleException:
Failed to initialize component [Connector[AJP/1.3-15009]] SEVERE:
Failed to initialize end point associated with ProtocolHandler
["ajp-bio-15009"] java.net.BindException: Permission denied
:15009 SEVERE: Failed to initialize end point associated with
ProtocolHandler ["ajp-bio-15009"] java.net.BindException: Permission
denied :15009
11. restarted step 6, this time left IP's as they were, changing only localhost to tomcat-stevenwernercs.rhcloud.com, same result but with original IP's
12. ran out of options online, then I posed this question...
13. then I edited it a lot...
14. patiently wait :)
That is everything I have done, I am not sure why php isnt finding Java.
I looked at previous questions didn't find anything helpful.
Open to anything, thank you
Gears in a non-scable application are not allowed to communicate on any non http/ws port. So if your php java bridge is trying to communicate with the tomcat instance on 15009 (from what i see above) that is not going to work. You could only make requests on 80/443/8000/8443. Can you verify what port the java bridge works over?
Alternate solution: https://bitnami.com/cloud
I got it working using Bitnami with Amazon AWS, it provides free service for 1 year, documentation that is easy to follow, and plentiful and up to date, It took less than an hour.
Disclaimer: Using ssh tunnel for port 8080 i configured tomcat as if on localhost, and moved my hosted .php to the
same microserver that also hosted the tomcat. (I gave up on trying to host php and tomcat separately.)
I have hosted tomcat separately before on my university's tomcat server. But that was a node I had full access to.
I would still like to try Openshifts free solution, although the current resources and methods I've seen seem to no longer be valid. And unfortunately the workarounds are not intuitive enough and are currently over my head. Thank you.

Unable to start WebLogic remotely to Debug

I setup my remote WebLogic server to debug, using these options:
-Xdebug -Xnoagent -Xrunjdwp:transport=dt_socket,address=${DEBUG_PORT},server=y,suspend=n -Djava.compiler=NONE"
I started WebLogic on the server and saw that it was listening on 8453 for dt_socket. I added the remote server on my local Eclipse and tested the connection. I also see that the server is STARTED and I can view the details. However, I'm unable to restart in DEBUG. I also stopped WebLogic on the server and now in Eclipse I see that it is stopped, but I'm not able to start it (the icons for debug and start are greyed out). When I set up my Remote Java Application in Eclipse I did check "Allow termination of remote VM".
Before stopping the server, the debug icon wasn't disabled and when I clicked it I got this message:
Cannot attach to remote server.
Please make sure the server myserver.com is running and listening for transport dt_socket at address: 8453
Failed to connect to remote VM. Connection refused.
Connection refused: connect
Instead of using java startup options, modify the following scripts:
setDomainEnv.sh -> make sure DEBUG_PORT is set ie. 8453
startWebLogic.sh -> set PRODUCTION_MODE=false and set debugFlag=true
Restart server, remote debug should work on port 8453.

Unable to deploy in Netbeans 6.7.1 and Glassfish v2.1.1

I am trying to deploy a simple WebService in Netbeans 6.7.1 and Glassfish v2.1.1 and am getting the following error. I am using GlassfishESBv2.2 and windows 7 machine. I have tried googling and implemented things as shown in
http://forums.netbeans.org/topic10055-0-asc-0.html . Still unable to deploy. Though the message says that application server is not started, from the Server tab , I am able to see a message which indicates Glassfish has started.Also , doing a netstat after trying to deploy returns this, which means that Glassfish is running.
C:>netstat -an | findstr "4848"
TCP 0.0.0.0:4848 0.0.0.0:0 LISTENING
I have been trying real hard to get this resolved. Any help is highly appreciated.
Error Message :
The Sun Java System Application Server could not start.
More information about the cause is in the Server log file.
Possible reasons include:
- IDE timeout: refresh the server node to see if it's running now.
- Port conflicts. (use netstat -a to detect possible port numbers already used by the operating system.)
- Incorrect server configuration (domain.xml to be corrected manually)
- Corrupted Deployed Applications preventing the server to start.(This can be seen in the server.log file. In this case, domain.xml needs to be modified).
- Invalid installation location.
C:\Users\xyz\Documents\NetBeansProjects\HWebService\nbproject\build-impl.xml:564: Deployment error:
The Sun Java System Application Server could not start.
More information about the cause is in the Server log file.
Possible reasons include:
- IDE timeout: refresh the server node to see if it's running now.
- Port conflicts. (use netstat -a to detect possible port numbers already used by the operating system.)
- Incorrect server configuration (domain.xml to be corrected manually)
- Corrupted Deployed Applications preventing the server to start.(This can be seen in the server.log file. In this case, domain.xml needs to be modified).
- Invalid installation location.
See the server log for details.
BUILD FAILED (total time: 29 seconds)
I've described the solution please visit here...
http://forums.netbeans.org/post-65058.html

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