JSP Tutorials - Herong's Tutorial Examples - v5.11, by Herong Yang
Refreshing Loaded JavaBean Classes
This section provides a tutorial example on how to refresh loaded JavaBean classes using the 'Reload' function on the Tomcat Application Manager.
Once a JavaBean class has been used once by a JSP page, it will stay loaded in memory to avoid loading it again when another JSP page uses it. This is good to improve response time, but it is a problem if you changed your JavaBean and wants to push the newer version into the server.
One way to force the server to use the new versions of JavaBean classes is to shut down the server and re-start the server.
But a better way to force the server to use the new versions is to use the Tomcat Manger tool. Here is how to do this:
1. Set up a manager user name and password by adding the following line to \local\tomcat\conf\tomcat-users.xml:
<role rolename="manager-gui"/> <user username="herong" password="s3cret" roles="manager-gui"/>
2. Shut down and re-start Tomcat server.
3. Visit UseBean.jspx with a Web browser.
4. Modify CacheBean.java, compile it, and copy the class file to \local\tomcat\webapps\ROOT\WEB-INF\classes\herong.
5. Go to http://localhost:8080/manager/ with IE and enter user name and password created in step 1.
6. Click the "Reload" button for the default application "/".
7. Visit UseBean.jspx again. You should see the changes made to CacheBean.java in step 4.
Table of Contents
JSP (JavaServer Pages) Overview
Tomcat Installation on Windows Systems
Syntax of JSP Pages and JSP Documents
►JavaBean Objects and "useBean" Action Elements
"jsp:useBean" Requires Fully Qualified Class Name
Servlet Class Converted from UseBean.jspx
Setting and Getting JavaBean's Properties
Using JavaBean Objects in Scripting Elements
Using Java Objects as JavaBeans
getProperty() Error on Tomcat 7
►Refreshing Loaded JavaBean Classes
Importing Unnamed Package Class Error
Using JavaBean without Import Element Error
Creating JavaBean Classes in Named Packages
"NoClassDefFoundError" Exception
Managing HTTP Response Header Lines
Non-ASCII Characters Support in JSP Pages
Overview of JSTL (JSP Standard Tag Libraries)
Multiple Tags Working Together
Using Tomcat on CentOS Systems
Connecting to SQL Server from Servlet