I'm using Tomcat 8.5.6 inside Eclipse 4.6.1. I have my web-app project/context foo, which has a JAX-RS (using RESTEasy 3.1.0.CR3) endpoint of bar, so I can fire up Tomcat inside Eclipse and access:
http://localhost:8080/foo/bar
I have a variable named foobar which I want to access inside my JAX-RS implementation using JNDI:
final String foobar = (String) new InitialContext().lookup("java:comp/env/foobar");
I plan on deploying the produced WAR in production using Tomcat autodeploy. I want to configure the foobar variable for Tomcat externally to the WAR. How can I do that so that I can test it in Eclipse?
After a lot of reading, I found what I thought to be the $CATALINA_HOME of Eclipse: …\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\. So I created a context file for foo at …\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\conf\Catalina\localhost\foo.xml to correspond to my project/context, and put the following inside it:
<?xml version="1.0" encoding="UTF-8"?>
<Context>
<Environment name="foobar" type="java.lang.String" value="123"/>
</Context>
Yes, I know that Eclipse erases this directory whenever I rebuild. But after building, I saved to file at least want to see if it works. It doesn't. I get an error:
javax.naming.NameNotFoundException: Name [foobar] is not bound in this Context. Unable to find [foobar].
I want to at least get it working so I can know how to do this in production, and worry later about the context file deletion thing in Eclipse. So what did I do wrong? Why can't Tomcat in Eclipse find this JNDI variable?
Note: I am not using a web.xml file and have no desire to do so; besides, this variable should be defined outside the WAR in the production deployment.
Update: The good news is that (on Windows 10 Professional Anniversary Edition 64-bit) using the same Tomcat but in standalone mode, I put the same foobar.xml file inside the standalone Tomcat's conf\Catalina\localhost\foo.xml, and my JAX-RS application picked it up just fine. So how can I define a JNDI variable in Tomcat inside Eclipse for testing?
It appears that in order to get Eclipse+Tomcat to recognize the per-module context files, you have to go into the server configuration (double-click on the server) and turn on the Publish module contexts to separate XML files. This way Tomcat will use the specific context XML file you created. Otherwise it apparently puts them in conf/server.xml and ignores the context-specific file you created.
There is still the problem that Eclipse regenerates this file each time you do a rebuild, destroying whatever JNDI variables you placed there. I'm trying to get the workaround in https://stackoverflow.com/a/22380248/421049 to work, but not yet succeeding. Anyone have any better ideas?
At least I'm able to reproduce a production environment now --- albeit temporarily, until the next rebuild.
Your link to Markus' answer on https://stackoverflow.com/a/22380248/1794485 allowed me to get this working, or at least as described in his workaround. But the remaining problem to solve was ordering.
As he said, you can workaround this by having a local copy of the META-INF/context.xml somewhere else, and adding this folder to the Deployment Assembly in the project properties of the Eclipse project.
This didn't pick up for me initially though. It looks like that while the Deployment Assembly in the properties shows as sorted by name, in fact it has an order like any other path. When I then removed the src/main/webapp entry (so the one containing the normal META-INF/context.xml) and added it back in, this effectively moved it down the pecking order. The next Tomcat deploy and startup in Eclipse finally put my preferred copy of META-INF/context.xml in .metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\myapp\META-INF
If in doubt about the true sequence of that Deployment Assembly path, have a look under your Eclipse project on the file system - at .settings\org.eclipse.wst.common.component.
Related
I am working with Intellij but some of my co-workers don't. When I was writing install doc, I realized that Tomcat is not managed the same way on the two IDEs.
Which is a problem considering what happened next when I tried to set up our project on Eclipse.
Basically, on Intellij, you select a Tomcat on your computer and it will literally copy the war into the webapps folder and run the server with everything working fine.
I am not a user of Eclipse so I might have misunderstood something, but I found that when you create a Tomcat server, it will embed the one you gave it to it. Doing that is a bit of an issue when you are working with logback, because usually you set your logs location directly into the Tomcat folder. And in Eclipse you are working out of this folder.
So, I can't run my application because it can't find the location of the logs folder at the fine place.
Is there a way to use Tomcat in Eclipse like Intellij? Or did I just miss something because I am kind of new with Eclipse?
See the FAQ: (1) (2)
I found that when you create a Tomcat server, it will embed the one you gave it to it.
You have to be more specific with your description. How you do things and what do you see. What do you mean by "embed"? What is the actual failure that you are observing with your logging?
There are different ways to do things.
For me by default Eclipse does not embed Tomcat, but runs it as a proper java process. (org.apache.catalina.startup.Bootstrap) You should be able to see it with jconsole and similar tools.
It runs your web application expanded, i.e. without zipping it into a war file. It creates a separate configuration of Tomcat, i.e. runs it with separate CATALINA_HOME and CATALINA_BASE directories (as documented in RUNNING.txt file of Apache Tomcat). The CATALINA_HOME directory stays untouched and CATALINA_BASE directory is ${workspace}/.metadata/.plugins/org.eclipse.wst.server.core/tmp0 etc. A logs directory can be found there.
One known caveat is that java.util.logging is not configured by default (the system properties java.util.logging.manager and others are not set). See "How do I enable the JULI logging" item in the FAQ. -- In the same way you will set any other system properties that you may need.
The default configuration of java.util.logging (as provided by JRE) is to log everything to the console, without creating any files.
I have an Eclipse Project which is attached to a Tomcat 6 using WST. For testing reasons I need to set some context parameters to override settings in the web.xml. The following Server Options are set: "Serve without publishing" as I want to run my application right from the project and "Publish contexts to separate XML files".
Now I can find the context fragment inside .metadata.plugins\org.eclipse.wst.server.core\tmp1\Conf\catalina\localhost and change them as needed. This works for some time, but after each Eclipse restart my context fragment is replaced with a fresh generated one - without the required parameters of course.
How can I prevent Eclipse from replacing my configuration? Or is there a way to add the necessary parameters to the generated context fragment?
Certainly changing stuff in the .metadata/.../wst.server is not a good idea - those directories are completely controlled by Eclipse.
If you look in your Eclipse 'Servers' project entry, you will see server.xml and context.xml - that is the place to change things. Eclipse copies those files to that .metadata directory - IF it isn't fouled up somehow.
How can I make sure that the server.xml which Eclipse produces for every separate project that relies on Tomcat, will always contain a specific option, which I added manually?
I'd like to add a bunch of <Context> mappings to the server.xml file. I tried doing that in the server.xml in the main tomcat dir - didn't work.
Then I saw that Eclipse builds a temporary folder for every project that uses Tomcat. This folder also containes this server.xml file. I edited it, and voila, it worked. However, soon after that the same file got updated by Eclipse, with the original data that it contained.
It is not very efficient to manually copy and paste the code every time before I run/restart tomcat. I hope there is a more permanent way.
Let's assume you have configured tomcat 5.5
If you have configured your tomcat server in eclipse using all default options, you want to edit the server.xml located at WORKSPACE_LOC\Servers\Tomcat v5.5 Server at localhost-config\server.xml
I have two tomcat web applications that need to share information using a singleton. I have already made it work by placing the jared classes in the tomcat common directory. Each webapp then gets the same copy of the singleton. What I would like to do is to integrate this behavior within eclipse. I would like the common classes to be a single project that gets incorporated into the tomcat common class loader every time I start the tomcat server within eclipse. Anyone knows how to configure eclipse to do this?
May be one possibility could be to extend the tomcat class loader in order for that class loader to search in other directories than WEB-INF/lib, this by:
Extending org.apache.catalina.loader.WebappClassLoader and override the findClassInternal method.
Configuring Tomcat to use the extended classloader.
This is done in the appropriate webapp configuration file under the Tomcat conf/Catalina/hostname path with the following element:
...
Then in eclipse, you could set your common project on the "Required projects on the build path", which makes it part of the classpath.
That means your extended classloader must be able to look for other classe:
either in a fixed pre-defined path
or in a pre-defined path within the classpath.
Not tested myself, but may be that can give you a lead on this issue.
A much simpler solution is proposed by noselasd in the comments, taking advantage of the GlobalNamingResources Component of Tomcat.
However, the FAQ does mentions:
When you create a new Tomcat server in Eclipse, the New Server wizard assumes it is not safe to affect the current behavior of the Tomcat installation that this new server will use.
WTP is able to avoid affecting the behavior of the installed Tomcat by using Tomcat's ability to run multiple server instances from a single installation. Thus, the default configuration for each new Tomcat sever you create will be a new server instance of the Tomcat installation associated with the Tomcat runtime selected in the wizard.
If you expect the new Tomcat server in Eclipse to run the same instance that the default batch files in your Tomcat installation run, you will likely be surprised when the Tomcat server in Eclipse doesn't behave as expected.
The Tomcat server configuration can be changed so that it does run the same instance as your Tomcat installation.
You will find here how to modify the server.xml in WTP.
I've managed to get it working. Here is what I did:
Created a common project in the eclipse workspace.
Created the two web applications, called first and second, that should share the common project.
When the web applications are created a Servers project is created with the tomcat configuration.
Change catalina.properties inside the Servers project and add the line shared.loader=/path-to-workspace/common/bin.
This works perfectly for development. Every time a new build is created everything is in sync. For deployment You need to convert the common project into a common.jar and place it in ${catalina.home}/lib.
I would like to collect some best-practices on deployment of a web-application to a running Tomcat. Not long ago I had to describe the deployment process of our web-application and the process appeared rather confusing.
Say, we have an application in a WAR file (foo.war) correctly configured and not requiring additional configuration. In this case, the deployment process is rather easy:
Copy the foo.war file to the $CATALINA_HOME/webapps directory. If the application starts correctly, the application will automatically deploy to $CATALINA_HOME/webapps/foo directory.
To undeploy the application:
Remove the foo.war file from the $CATALINA_HOME/webapps. If the application unloads correctly, it will be unloaded and the $CATALINA_HOME/webapps/foo will be removed.
Now I want to override some context parameters in my running application. Having read the docs, all I need to do:
Create a context.xml file called foo.xml
Copy the file to the $CATALINA_BASE/conf/[enginename]/[hostname]/ directory.
Unfortunately, that did not work: the application would not restart. Empirically, we found out that the only working solution is when the war file is deployed to a location outside the $CATALINA_HOME/webapps.
Besides, the default values of the configurable context parameters in the WAR file should be specified in the web.xml, since context.xml in the WAR file is not read when there is a context.xml outside.
Here is an easy example of the foo.xml:
<?xml version='1.0' encoding='utf-8'?>
<Context docBase="/path-to-deployment-directory/foo.war">
<Parameter name="myparam" value="newvalue" override="false"/>
</Context>
Be sure to specify override=false for the parameter if you want the 'newvalue' to override the value specified in the WAR's web.xml. This was not obvious for us.
Thus, to deploy an aplication to a running Tomcat:
Create a context.xml file called foo.xml
Copy the file to the $CATALINA_BASE/conf/[enginename]/[hostname]/ directory.
Copy the foo.war to the location specified in the docBase of the foo.xml; the application will deploy automatically.
To apply new context parameters:
Add the parameter values to the foo.xml and save the file; the application will re-deploy automatically.
To undeploy the application:
Remove the foo.xml from the $CATALINA_BASE/conf/[enginename]/[hostname]/ directory
Note that removing the foo.war will also work, but will remove the foo.xml as well.
By now, I have the following questions:
Is it a best-practice at all to deploy a web-application without stopping the tomcat? I heard an opinion that deployment to a running tomcat is never needed since people run each application in a separate tomcat.
Is it a good idea to copy WAR files to $CATALINA_HOME/webapps or they should better be kept in a separate location?
How can I configure an application deployed to $CATALINA_HOME/webapps
Why there is no INFO line in the catalina.out for deployment of an application and there is one for undeployment? Is it configurable?
On question (1), Tomcat works great for deploying servlets into a running server. There may be concerns w.r.t. security or possibly D.O.S. or provisioning reasons why you would have separate server instances.
You have the flexibility to do either way, but it is often more convenient to deploy to an already running server. This is a BUILT-IN feature in the servlet architecture. :)
For (2), again it is at your discretion where you you want to put WARs. It sounds like you already have it configured a non-standard (non-default I should say) way. Check your server.xml file for the settings in your server instance(s). Check for attributes like unpackWARs and autoDeploy.
For (3) and (4), plus your (1,2) questions, it might be a good idea to consult the Tomcat docs for your version of Tomcat on its deployment model. You should be able to use the same docs to figure out how your server has been configured.
See Tomcat Web Application Deployment in the Tomcat manual, adjusting for your version of Tomcat.
One solution would be to use the manager application. If you decide that is safe to use it, then you can easily deploy, start, stop and undeploy applications:
http://localhost:8080/manager/deploy?path=[context_path]
http://localhost:8080/manager/start?path=[context_path]
http://localhost:8080/manager/stop?path=[context_path]
http://localhost:8080/manager/undeploy?path=[context_path]
There are ant tasks that can help you with these.
I am guessing, but do not know for sure, that stopping and starting an application will make it reread the context.xml.
Regarding your second question, I believe it is better for maintenance reasons to keep the war files in the webapps directory.