将战争应用程序名称与战争文件名分开

Question

Currently if i deploy a war file on tomcat named say myapp.war , I can access its url by http://localhost/myapp/MyServlet .

However what I want is to deploy a war with a version number in the war file name and still have the same url. For eg, I want to deploy myapp-1.1.0.war and still have the url be http://localhost/myapp/MyServlet

Of course I need to keep updating the war and the version number will keep changing, so I cant hardcode the war filename anywhere. Is there any setting in web.xml I can use to keep the same url for the app regardless of the war filename?

Answer 1

The solution is to stop using the automatic deployment feature of Tomcat, which takes the shortcut of setting the "context name" (the /myapp part of the URL) to the portion of the WAR filename before ".war".

Instead, extract the WAR contents to the filesystem yourself and setup an XML file at TOMCAT_HOME/conf/[enginename]/[hostname]/[contextname].xml which points the desired context path (such as /myapp ) to the location of the application on disk (such as /opt/webapps/myapp-1.1.0/ ).

The Tomcat reference docs provide a good explanation of how Tomcat deploys applications automatically, and how you can configure customized logic for the mapping of context path to application file location (there are a handful of alternate ways to set this up other than the one I suggest above).

Answer 2

You can use YOUR_WAR/META-INF/context.xml for this. Here is a sample:

<?xml version="1.0" encoding="UTF-8"?>
<Context antiJARLocking="true" path="/MyServlet"/>

Answer 3

When using Maven you can control your deployment's path by doing the followings:

Tomcat's conf/tomcat-users.xml:

<tomcat-users>
  <role rolename="manager-gui"/>
  <role rolename="manager-script"/>
  <role rolename="manager-jmx"/>
  <role rolename="manager-status"/>
  <role rolename="admin-gui"/>
  <role rolename="admin-script"/>

  <user username="root" password="root" roles="manager-gui,manager-script,manager-jmx,manager-status,admin-gui,admin-script"/>

</tomcat-users>

~/.m2/settings.xml:

...
<server>
  <id>tomcat</id>
  <username>root</username>
  <password>root</password>
</server>
...

pom.xml:

...
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.example</groupId>
  <artifactId>myapp</artifactId>
  <version>1.1.0</version>
  <packaging>war</packaging>
...
  <build>
    <plugins>
      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>tomcat-maven-plugin</artifactId>
        <configuration>
          <!-- neglect /html below Tomcat7: -->
          <url>http://server:8080/manager/html</url>
          <!-- Refer to the server settings in your ~/.m2/settings.xml -->
          <server>tomcat</server>
          <path>/myWebApp</path>
        </configuration>
      </plugin>
      ....
    </plugins>
  </build>
...

Start your tomcat first Then build and deploy your application..

mvn clean install tomcat:deploy

..it will be accessible under http://server:8080/myWebApp

Answer 4

I prefer to use " ## " symbols for noting version of *.war files in the tomcat.
For example:
myapp.war -> URL: http://localhost:8080/myapp/MyServlet
myapp##1.1.0 -> URL: http://localhost:8080/myapp/MyServlet (still the same, because all symbols after " ## " are ignoring by tomcat)

Answer 5

There is no setting in web.xml for this. I do not believe that it is possible to set this inside the war file in a cross-container way - there is no mention of it in the spec anyway - so each container does it differently. jboss-web.xml , sun-web.xml , context.xml etc.

Answer 6

I run into the same issue, and indeed, as @matt mentioned, the Tomcat reference docs provide a good explanation of how Tomcat deploys applications automatically, and how you can configure customized logic for the mapping of context path to application file location.

In my case, I used this advice (in 'path' explanation):

Even when statically defining a Context in server.xml, this attribute (/path) 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.

so in my case, I switched both deployOnStartup and autoDeploy to false, so my WAR (egaWAR) was not auto-exploded to 'a' directory under webapps, but instead into 'b' directory, due to these settings:

<Host name="localhost"  appBase="webapps"
            autoDeploy="false" deployOnStartup="false" 
            unpackWARs="true" deployIgnore="${ignore.context}">

   <Context docBase="a" path="/b" />

</Host>

Answer 7

I found all the advice on this subject somewhat terse and confusing. The below method works for me using a default tomcatee installation.

Suppose I have a war file named mywar.war. This holds a servlet mapping to '/hello'. I want to access this servlet from a url like localhost:8080/myapp/hello

This method avoids any changes to server.xml which is not advised as this requires tomcat restarts.

This method will fail is you deploy to /webapps as it will try and deploy the same war twice. Therefore I start by creating a new directory to deploy into. I use /apps but the dir name is arbitrary.

I now copy mywar.war into apps. Tomcat ignores this action. I now create a simple deployment file named myapp.xml. Note that the name of this file defines the URL context the war will be deployed under. I believe you can use ROOT.xml to deploy under. The contents are as follows:

As described this needs to be copied into /conf/Catalina/localhost This causes tomcat to expand and deploy the /apps/mywar.war and set the correct URL context. The servlet is now available on localhost://myapp/hello (or:8080//myapp/hello from a remote client).

Note that for a relative address the docBase URL identifies the location of the war from the webapps directory - hence the leading..