Develop Reference

error resolving localhost while running java servlets in eclipse's browser

I am new to java servlets. I have installed apache-tomcat-9.0.0.M21.
When I run the project containing servlet in eclipse browser, sometimes I get the error-
Error resolving 'localhost': Name or service not known.
Other times the error is -
Error resolving 'localhost' : Temporary failure in name resolution.
This project runs fine in my web browser.
Also, after I add <servlet>...</servlet> and <servlet-mapping>...<servlet-mapping> in web.xml, I get the error - Server Tomcat v9.0 Server at localhost failed to start.
One more thing, I use Ubuntu operating system (if it has to do something with the question).
Please help. I googled for the solution but I am not able to resolve the error.

Try adding the below to your /etc/hosts file.
127.0.0.1 localhost

Activiti Explorer - Request resource is not available

I have big problem to run activiti-explorer when i try access: http://localhost:8080/activiti-explorer/ tomcat shows me HTTP Status 404 - The requested resource is not available. I'm really don't have any idea why that dosen't work. Can you help me?
This what have I done on my PC:
I'm using 5.19.0 version of activiti-explorer
7.0.63 tomcat
JDK 1.8.0.77 (i think there is no point to downgrade java to previous versions (<=1.7) becouse my main application using this version)
I'm sure I have correctly configured environment variables (JAVA_HOME,JRE_HOME,PATH,CATALINA_HOME)
I configured data base connection (db.properties, context.xml) in activiti-explorer.war and i moved this file to tomcat/webapps
I don't have any errors about activiti during tomcat start

Check if activiti explorer is deployed to tomcat in manager.
http://{host}:{port}/manager/html
More info in https://tomcat.apache.org/tomcat-7.0-doc/manager-howto.html

Check the catalina.out log. There will be something in there that leads you to the solution.

Check Admin Console (cmd that runs behind) after hitting the link. most recent exception occurred will be displayed there.

install jenkins into weblogic

I'm trying to install jenkins into weblogic server
If I deploy normally to weblogic, this error evoke.
Error 500--Internal Server Error
From RFC 2068 Hypertext Transfer Protocol -- HTTP/1.1:
10.5.1 500 Internal Server Error
The server encountered an unexpected condition which prevented it from
fulfilling the request.
https://wiki.jenkins-ci.org/display/JENKINS/Weblogic
in this article, It says make some code and drop to WEB-INF of war directory.
But I can not find WEB-INF of jenkins,and If I make WEB-INF, this error still evoke.
How Can I install jenkins into weblogic?

I solved this problem.
I was use jenkins 2.X version and this error evoke.
When I downgrade to 1.615.3 version, this error erased.
So you must use this version.

Unable to start server in Eclipse Gallileo IDE with WAS7

Server not starting in Eclipse Gallileo IDE with WAS7.
I run the server from outside of Eclipse but I want to start it from within the eclipse
Below are the details of my Workspace configurations :
Eclipse Java EE IDE for Web Developers.
WAS 7.0
An alert is coming saying "Cannot connect to VM socket closed".
I got the following exception in console :
JVMSHRC154E Escape character g not valid for cache name
<JIT: FullSpeedDebug: ignoring countString>
<JIT: FullSpeedDebug: ignoring countString>
JVMJ9VM015W Initialization error for library j9shr24(13): JVMJ9VM009E J9VMDllMain failed

Per the JVMSHRC154E, it appears that somehow -Xshareclasses:name=...%g... is being added to your server JVM command line. I do not know why there would be a difference between Eclipse and the command-line (perhaps a product issue that should be reported to IBM), but you could try working around the issue by adding -Xshareclasses:nonfatal to your server's generic JVM arguments.

IBM has released development tools for WebSphere Application Server (WAS).
You can download it from eclipse market place.
There are tools for the WAS7 and up. (IBM Information page)
You probably need WAS 7 Tools - marketplace page.
The short instruction is:
In the eclipse click Help->Eclipse Market Place->Search WebSphere Application Server Tools.

Inside eclipse installation folder go to \plugins.....\cdcla\eclipse\launch\simple.
Open the file websphere70.properties.
You will see the following content and remove the
"_%g"
part and save it
shareclasses=webspherev70_%g,groupAccess,nonfatal

Migrating To Weblogic From Tomcat

I have a web application running on tomcat. I want to deploy it on a weblogic server but i get some problems.
Error(s) found in module 'BatchMonitoring'. Publish was cancelled. See "Problems" view for details.
Target runtime SpringSource dm Server (Runtime) v1.0 is not defined. at BatchMonitoring
Java compiler level does not match the version of the installed Java project facet. at BatchMonitoring
java.lang.IllegalArgumentException: Cannot find state with id 'displayError' in flow 'admin_main' -- Known state ids are 'array<String>['queryAll', 'mainForm', 'register']'
at org.springframework.webflow.engine.Flow.getStateInstance(Flow.java:348)
at org.springframework.webflow.engine.support.DefaultTargetStateResolver.resolveTargetState(DefaultTargetStateResolver.java:60)
at org.springframework.webflow.engine.Transition.execute(Transition.java:217)
at org.springframework.webflow.engine.impl.FlowExecutionImpl.execute(FlowExecutionImpl.java:391)
at org.springframework.webflow.engine.impl.RequestControlContextImpl.execute(RequestControlContextImpl.java:214)
at org.springframework.webflow.engine.support.TransitionExecutingFlowExecutionExceptionHandler.handle(TransitionExecutingFlowExecutionExceptionHandler.java:110)
at org.springframework.webflow.engine.FlowExecutionExceptionHandlerSet.handleException

Seems like you had problems with Java versions of what Tomcat is using(points to JAVA_HOME) at environmental variable and JDK of Weblogic. Also it would be good if you send some logs and exception messages.