Question

I deploy a application to tomcat with context xml. I want the tomcat work at debug mode, I means if I change something inside a function, like change
String a=”123″;
to
String a=”456″;
tomcat should get the change without reload the application.

The web01.xml under %CATALINA_HOME%/conf/Catalina/localhost

<?xml version='1.0' encoding='utf-8'?>
<Context docBase="d:/document/workspace3.6/web01/WebContent" path="/web01" reloadable="false" debug="1" ></Context>

but now tomcat didn’t worked as I expected, if I replace the old class file with new version, I must restart tomcat to get the change.

Why tomcat didn’t reload the class,How should I do to let it work as debug mode?

I am not use Eclipse now. and I don’t want to set reloadable=”true”, this will reload the entire application if class changed.

I used tomcat5.5.23

Answer 1

Ok, here’s an actual example:

I have the cnas-war maven project. Once I build it with Maven, I get the following directory:

c:/_andrei/work/cnas/cnas-war/target\cnas-war-0.0.1-SNAPSHOT

In here I have all the stuff that normally would get packaged in the .war file, like .class files, .jsp files, .jar files etc. Effectively it’s the .war file exploded.

I also have a Tomcat 5.5 specifically tailored for the deployment of this war, cleverly placed in the tomcat_cnas folder. In the Tomcat config file (conf\server.xml) I have the following:

    <?xml version="1.0" encoding="utf-8"?>
<!-- Example Server Configuration File -->
<!-- Note that component elements are nested corresponding to their
     parent-child relationships with each other -->
<!-- A "Server" is a singleton element that represents the entire JVM,
     which may contain one or more "Service" instances.  The Server
     listens for a shutdown command on the indicated port.

     Note:  A "Server" is not itself a "Container", so you may not
     define subcomponents such as "Valves" or "Loggers" at this level.
 -->
<Server port="8125" shutdown="SHUTDOWN">
  <!-- Comment these entries out to disable JMX MBeans support used for the 
       administration web application 
  <Listener className="org.apache.catalina.core.AprLifecycleListener" />
  <Listener className="org.apache.catalina.storeconfig.StoreConfigLifecycleListener"/> -->
  <Listener className="org.apache.catalina.mbeans.ServerLifecycleListener" />
  <Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />
  <!-- Global JNDI resources -->
  <GlobalNamingResources>
    <!-- Test entry for demonstration purposes -->
    <Environment name="simpleValue" type="java.lang.Integer"
    value="30" />
    <Resource auth="Container"
    configurationDirectory="c:/cnas-content"
    factory="com.genia.toolbox.web.jndi_config.StringContainerFactory"
    name="string/activitymanagerConfigurationContainer"
    type="com.genia.toolbox.web.jndi_config.StringContainer" />
    <Resource name="string/activitymanagerConfigurationContainer"
    auth="Container"
    type="com.genia.toolbox.web.jndi_config.StringContainer"
    factory="com.genia.toolbox.web.jndi_config.StringContainerFactory"
    configurationDirectory="c:/cnas-content" />
  </GlobalNamingResources>
  <!-- Define the Tomcat Stand-Alone Service -->
  <Service name="Catalina">
    <!-- Define a non-SSL HTTP/1.1 Connector on port 8080 -->
    <Connector acceptCount="100" connectionTimeout="20000"
    disableUploadTimeout="true" enableLookups="false"
    maxHttpHeaderSize="8192" maxSpareThreads="75" maxThreads="150"
    minSpareThreads="25" port="8081" redirectPort="8443" />
    <!-- Define the top level container in our container hierarchy -->
    <Engine defaultHost="localhost" name="Catalina">
      <!-- for activitymanager -->
      <Host name="localhost" appBase="webapps" unpackWARs="true"
      autoDeploy="true" xmlValidation="false"
      xmlNamespaceAware="false">
        <Context path="/cnas"
        docBase="c:/_andrei/work/cnas/cnas-war/target/cnas-war-0.0.1-SNAPSHOT/"
        workDir="c:/_andrei/work/cnas/cnas-war/target/work-cnas/">
          <ResourceLink name="string/configurationContainer"
          global="string/activitymanagerConfigurationContainer"
          type="com.genia.toolbox.web.jndi_config.StringContainer" />
          <Resource name="bean/cnasConfig" auth="Container"
          type="com.genia.toolbox.projects.cnas.war.config.CnasConfig"
          factory="org.apache.naming.factory.BeanFactory"
          classpath="false" fileSystem="true"
          applicationFileLocation="c:/cnas-content/application.properties" />
          <Resource name="bean/cnasApplicationData"
          auth="Container"
          type="com.genia.toolbox.projects.cnas.war.config.CnasConfig"
          factory="org.apache.naming.factory.BeanFactory"
          classpath="false" fileSystem="true"
          applicationFileLocation="c:/cnas-content/cnas_application_data.xml" />
        </Context>
        <!--Context docBase="C:/travail/workspace/cnas/cnas-ws-proxy/target/webapp" path="/proxy">

                <Resource name="bean/params" 
                    auth="Container"
                    type="fr.genia.cnas.config.Parameters" 
                    factory="org.apache.naming.factory.BeanFactory"
                    log4jFile="" 
                    serviceUrl="" 
                    debugMode="true" >

                </Resource>

            </Context-->
      </Host>
    </Engine>
  </Service>
</Server>

As you can see, in the “context” tag I have a docBase property pointing to the snapshot directory (the one where the war is exploded after maven builds it). Now, with this setup, and having this project imported into Eclipse, if I do a maven build, and then start this Tomcat, the war will be deployed and running. At this point, if I modify the content of a method in a .java file inside Eclipse (and save), then that code will be automatically taken into account by Tomcat and the application will behave differently, without any extra re-deployment. Hope this helps