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Tomcat set application context using configuration (not war name)

My question is this - Say I have a war file called my-app-123.war. I want to deploy it on a Tomcat server (9.0.x), let it auto unpack.
The application would then be accessible by http://localhost:8080/my-app-123
Is there a way, without renaming the war file, to make the application accessible from http://localhost:8080/my-app?
I will preface this by saying I realize the easiest solution is to just name the war file. I'm curious if there is a way to do this in Tomcat configurations.
I did do this already (inside the host section of my server.xml file):
<Context path="/my-app" docBase="my-app-123"></Context>
But I read this online (https://tomcat.apache.org/tomcat-7.0-doc/config/context.html) in the path variable description:
Even when statically defining a Context in server.xml, this attribute must not be set unless either the docBase is not located under the Host's appBase or both deployOnStartup and autoDeploy are false. If this rule is not followed, double deployment is likely to result.
And I can access the app now at http://localhost:8080/my-app and http://localhost:8080/my-app-123, which isn't a real solution.

The following works for Tomcat deployments I have used - there are no double-deployment issues.
In the example I will use here, I have a simple "hello world" webapp in TomcatDemo-1.0-SNAPSHOT.war. It is deployed on Tomcat 9.0 in the standard location (webapps directory).
I want the application's context path to be /my-foo-app.
I use the following context entry in server.xml:
<Context path="/my-foo-app" docBase="TomcatDemo-1.0-SNAPSHOT.war"></Context>
I also use the following in server.xml:
<Host name="localhost"
appBase="webapps"
deployOnStartup="true"
deployIgnore="TomcatDemo-1.0-SNAPSHOT.war"
unpackWARs="true"
autoDeploy="false">
The important item here is deployIgnore. It is described here:
https://tomcat.apache.org/tomcat-9.0-doc/config/host.html#Automatic_Application_Deployment
When using automatic deployment, the docBase defined by an XML Context file should be outside of the appBase directory. If this is not the case, difficulties may be experienced deploying the web application or the application may be deployed twice. The deployIgnore attribute can be used to avoid this situation.
Alternatively, if you don't mind about automatic start-up deployments, you can set deployOnStartup="false" - in which case you don't need deployIgnore.
In these scenarios, the web app is available only here:
http://localhost:8080/my-foo-app/ <-- OK
Otherwise, as you note, with double-deployment the web app would also be available here (and you would see two exploded directories in webapps):
http://localhost:8080/TomcatDemo-1.0-SNAPSHOT/ <-- BAD!
Hope that helps.
Finally, it can get a little complicated, with all the various auto-deployment options. This page provides a set of summary tables and explanations:
https://tomcat.apache.org/tomcat-9.0-doc/config/automatic-deployment.html

Java configure context root of web application

I have a Java web application using Wicket 6, Spring 3.2 and WildFly 8.2.0. Right now i'm setting the context root of my web application in the jboss-web.xml file like this:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE jboss-web PUBLIC "-//JBoss//DTD Web Application 5.0//EN" "http://www.jboss.org/j2ee/dtd/jboss-web_5_0.dtd">
<jboss-web>
<context-root>/myCustomContextRoot</context-root>
</jboss-web>
The jboss-web.xml file is compiled into the war. Now some clients want to change this context root to an empty context root. So i hace to recompile a version of my app per different context root. Is there a way to set the context root of my application from outside .war, programatically from a .properties file, or any other way for example in standalone.xml of WildFly 8.2.0?

Set the runtime name when deploying your web application. Suppose your WAR is called myapp-1.0.0-SNAPSHOT.war. Using a runtime name of foo.war, the context root will be /foo.
Using a runtime name of ROOT.war, the context root will be /.
The runtime name can be set when deploying via the Web Console or via the CLI.

Thanks for your Answer Harald Wellmann. It answers the question and pointed me into the right direction!
Some things I had to find out on my own and which may help others:
the exact syntax in jboss-cli to specify a runtime-name is:
deploy path_to_war_file --runtime-name=wantedName.war
This leads to a context-root of /wantedName/ for the webapp.
The runtime-name does not have any effect on the context-root, if the war file contains a jboss-web.xml in WEB-INF which in turn contains a context-root tag.
That is, if you want to control the context-root of your web-app in WildFly at deployment time, you must not specify any context-root in jboss-web.xml.
It is ok to have a jboss-web.xml without a context-root tag if you want to take advantage of the runtime-name to control the context-root.
I tested this on WildFly 9.0.1 and 9.0.2:
Hope this helps!

Tomcat: Get short URL for Jersey based Rest Service

I have a Jersey based Rest service running on a tomcat server. There is no UI, just a server that offers some rest services. Now, to access this service the URL that i have to type in is pretty long. Something like localhost:8080/MyApp/url_pattern/classPath/method where MyApp is the webapp that i deployed, url_pattern is the pattern that i defined in the servlet-mapping in web.xml, classPath and method being the #Path annotations for the Class and method respectively. Is it possible to shorten it such that I get rid of the MyApp and url_pattern part of this URL. Something like localhost:8080/classPath/method.
PS: There is just one webApp running on this server, so no point having the MyApp part

I don't think you can remove all what you desire from the url but you can definitely remove the MyApp part by making it the root application for tomcat.
Answer on this related link describes it pretty well, how to set your application as the root application. So you can access your REST services without having the app name in url:
Setting default application in tomcat 7
Content copied from the above link:
First Method:
first shutdown your tomcat [from the bin directory (sh shutdown.sh)]
then you must delete all the content of your tomcat webapps folder (rm
-fr *) then rename your WAR file to ROOT.war finally start your tomcat [from the bin directory (sh startup.sh)]
Second Method:
leave your war file in CATALINA_BASE/webapps, under its original name
- turn off autoDeploy and deployOnStartup in your Host element in the server.xml file. explicitly define all application Contexts in
server.xml, specifying both path and docBase. You must do this,
because you have disabled all the Tomcat auto-deploy mechanisms, and
Tomcat will not deploy your applications anymore unless it finds their
Context in the server.xml.
Note:
that this last method also implies that in order to make any change to
any application, you will have to stop and restart Tomcat.
Third Method:
Place your war file outside of CATALINA_BASE/webapps (it must be
outside to prevent double deployment). - Place a context file named
ROOT.xml in CATALINA_BASE/conf//. The single element in this context
file MUST have a docBase attribute pointing to the location of your
war file. The path element should not be set - it is derived from the
name of the .xml file, in this case ROOT.xml. See the Context
Container above for details.

Tomcat configuration for development, how to add a webapp, as well as reference static files

I want to have a web app and then configure it to load static files from a direct path.
This is the webapp configuration:
<Context docBase="E:\webapp1" path="/" reloadable="true"/>
How do I setup the static resources.

I assume your Tomcat already can run at http://localhost:8080/
All you need to do then is to put your static resources in sub-folders of
E:\webapp1
like
E:\webapp1\jpg\1.jpg
E:\webapp1\css\style.css
E:\webapp1\html\abc.html
Change the path in Context to "" so this webapp can run as the default webapp i.e. the webapp name will not be part of the URL
and you can directly serve these as
http://localhost:8080/jpg/1.jpg
http://localhost:8080/css/style.css
http://localhost:8080/html/abc.html
Is this what you were looking for? This is my understanding of your question

customize web application root context in apache

I have web application abc.war and I want to deploy it on Apache Tomcat.
The problem is that, by default, the path to this application is http://<server-name>/abc
but I want to access it as http://<server-name>/xyz.
I put into WAR's META-INF folder the file context.xml that is :
<Context path="/xyz" docBase="abc" override="true" />
The application WAR abc.war is located under %CATALINA_HOME%\webapps and it is extracted to %CATALINA_HOME%\webapps\abc folder.
Also, while deployment, the file context.xml from abc/META-INF is copied to %CATALINA_HOME%\conf\Catalina\localhost as abc.xml
It seems that this should work, but I still can't access my application through http://<server-name>/xyz, but only through http://<server-name>/abc
In addition, I still see in apache log the following line while deployment of abc.war :
context path = /abc
Could anybody, please, help while this doesn't work, or tell if there is any way of deploying of web application on apache such that application could be accessed by customized path (that does not relate to war-file name) ?
Thanks in advance.

Take a look at the docs:
The context path of this web application, which is matched against the beginning of each request URI to select the appropriate web application for processing. All of the context paths within a particular Host must be unique. If you specify a context path of an empty string (""), you are defining the default web application for this Host, which will process all requests not assigned to other Contexts.
The value of this field must not be set except when statically defining a Context in server.xml, as it will be inferred from the filenames used for either the .xml context file or the docBase.