The description below uses the variable name $CATALINA_BASE to refer the base directory against which most relative paths are resolved. If you have not configured Tomcat for multiple instances by setting a CATALINA_BASE directory, then $CATALINA_BASE will be set to the value of $CATALINA_HOME, the directory into which you have installed Tomcat.
從上述描述可以看出$CATALINA_HOME和$CATALINA_BASE的區別：簡單說就是$CATALINA_HOME表示Tomcat的安裝目錄,$CATALINA_BASE表示Tomcat的工作目錄。
對於$CATALINA_HOME和$CATALINA_BASE的配置可以參考http://tomcat.apache.org/tomcat-7.0-doc/RUNNING.txt如下：
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Advanced Configuration - Multiple Tomcat Instances
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In many circumstances, it is desirable to have a single copy of a Tomcat
binary distribution shared among multiple users on the same server. To make
this possible, you can set the CATALINA_BASE environment variable to the
directory that contains the files for your 'personal' Tomcat instance.
When running with a separate CATALINA_HOME and CATALINA_BASE, the files
and directories are split as following:
In CATALINA_BASE:
* bin - Only the following files:
* setenv.sh (*nix) or setenv.bat (Windows),
* tomcat-juli.jar
The setenv scripts were described above. The tomcat-juli library
is documented in the Logging chapter in the User Guide.
* conf - Server configuration files (including server.xml)
* lib - Libraries and classes, as explained below
* logs - Log and output files
* webapps - Automatically loaded web applications
* work - Temporary working directories for web applications
* temp - Directory used by the JVM for temporary files (java.io.tmpdir)
In CATALINA_HOME:
* bin - Startup and shutdown scripts
The following files will be used only if they are absent in
CATALINA_BASE/bin:
setenv.sh (*nix), setenv.bat (Windows), tomcat-juli.jar
* lib - Libraries and classes, as explained below
* endorsed - Libraries that override standard "Endorsed Standards"
libraries provided by JRE. See Classloading documentation
in the User Guide for details.
By default this "endorsed" directory is absent.
In the default configuration the JAR libraries and classes both in
CATALINA_BASE/lib and in CATALINA_HOME/lib will be added to the common
classpath, but the ones in CATALINA_BASE will be added first and thus will
be searched first.
The idea is that you may leave the standard Tomcat libraries in
CATALINA_HOME/lib and add other ones such as database drivers into
CATALINA_BASE/lib.
In general it is advised to never share libraries between web applications,
but put them into WEB-INF/lib directories inside the applications. See
Classloading documentation in the User Guide for details.
It might be useful to note that the values of CATALINA_HOME and
CATALINA_BASE can be referenced in the XML configuration files processed
by Tomcat as ${catalina.home} and ${catalina.base} respectively.
For example, the standard manager web application can be kept in
CATALINA_HOME/webapps/manager and loaded into CATALINA_BASE by using
the following trick:
* Copy the CATALINA_HOME/webapps/manager/META-INF/context.xml
file as CATALINA_BASE/conf/Catalina/localhost/manager.xml
* Add docBase attribute as shown below.
The file will look like the following:
<?xml version="1.0" encoding="UTF-8"?>
<Context docBase="${catalina.home}/webapps/manager"
antiResourceLocking="false" privileged="true" >
<Valve className="org.apache.catalina.valves.RemoteAddrValve"
allow="127\.0\.0\.1" />
</Context>
See Deployer chapter in User Guide and Context and Host chapters in the
Configuration Reference for more information on contexts and web
application deployment.