How to set tomcat work at debug mode?

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 vers开发者_运维知识库ion, 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

You're actually confusing the notions of "debugging" and hot deploy. You can configure Tomcat for debug mode, and then remotely debug your application running inside tomcat such that when you add a break point in your code, the debugger will jump to that breakpoint and halt execution.

What you actually need there is having the possibility to hotdeploy an application. With tomcat, if you modify the .java files and then copy them to the working directory of tomcat, you'll get exactly what you want, namely the ability to change something in a class and have the running tomcat-deployed application take it into account without redeploying the whole application. You can automatize this by configuring your tomcat application context (either in the tomcat server.xml file or in a project specific context.xml file) for your application to have as working directory the directory where your project code gets compiled.

here's an actual example:

Let's say you have a maven project in the directory c:\myProject. You'd have source files in the c:\myProject\src, and then when compiling it you'd get the war file and an exploded directory of the war file content in the c:\myProject\target\myProject.war and respectively c:\myProject\target\myProject. Now, if you configure your tomcat such that for the myProject tomcat context, youd have the working directory configured as c:\myProject\target\myProject, then each time you modify a .java file, the .class corresponding file will be updated in the target (and now also working) dir, and tomcat will take it into account.

I've actually used such a setup to develop with tomcat, but it's not the best. First off tomcat will hotdeploy only certain modifications, such as when you modify something in the body of an existing method. Other modifications will not be taken into account, such as adding a new method - for this you have to do a full redeploy to have it taken into account.

A far better solution is to use maven with the maven jetty plugin. This thing really works as you want: any modification you do to a class of jsp file will me immediately taken into account, and visible in the running app inside jetty.

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

How to configure Tomcat 5.5 for debug mode?

To do what you are trying to do, You would need some thing like java rebel or some thing similar I know there are some open source alternatives to do the same.