Tomcat 5.0 & JavaBean

Question

I'm getting in trouble with Tomcat & JavaBean.
1) I've installed Tomcat 5.0 in the following directories:
"C:\Programmi\Apache Software Foundation\Tomcat 5.0"
2) I've started Tomcat and I tried it in "http://localhost:8080". Tomcat Web Server works perfectly.
3) I've created the following simple JavaBean (prova.java). It do nothing. I've compiled it (using JcreatorLE ide) and I copied files in the following directory:
"C:\Programmi\Apache Software Foundation\Tomcat 5.0\webapps\ROOT\ServiceDiscovery\WEB-INF\classes"
4) prova.java 's code is very simple:
public class prova
     public prova()
5) Under the main Tomcat's directory ("C:\Programmi\Apache Software Foundation\Tomcat 5.0\webapps\ROOT") I've created a new directory ("ServiceDiscovery"). In this directory I've copied the "WEB-INF" directory which was in the Tomcat's main directory. The current directory state is:
C:\Programmi\Apache Software Foundation\Tomcat 5.0\webapps\ROOT\ServiceDiscovery
|
+--- WEB-INF (directory)
| |
| +--- classes (directory)
| | |
| | +--- org\apache\jsp\index_jsp.class
| | |
| | +--- prova.java
| | |
| | +--- prova.class
| |
| +--- lib (directory)
| |
| +--- web.xml
|
+--- index.jsp
5) I've edited the following script at the beginning (first line) of index.jsp:
"<jsp:useBean id="prova" class="prova" scope="session" />"
6) When I open Internet Explorer at the URL "http://localhost:8080/ServiceDiscovery", Tomcat server reply with this error message:
org.apache.jasper.JasperException: /ServiceDiscovery/index.jsp(3,0) The value for the useBean class attribute provami.prova is invalid.
     org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:39)
     org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:376)
     org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:150)
     org.apache.jasper.compiler.Generator$GenerateVisitor.visit(Generator.java:1217)
     org.apache.jasper.compiler.Node$UseBean.accept(Node.java:1116)
     org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2163)
     org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2213)
     org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2219)
     org.apache.jasper.compiler.Node$Root.accept(Node.java:456)
     org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2163)
     org.apache.jasper.compiler.Generator.generate(Generator.java:3261)
     org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:244)
     org.apache.jasper.compiler.Compiler.compile(Compiler.java:461)
     org.apache.jasper.compiler.Compiler.compile(Compiler.java:442)
     org.apache.jasper.compiler.Compiler.compile(Compiler.java:430)
     org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:511)
     org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:274)
     org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
     org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
I don't understand what's going wrong? Something in my script? Something in my JavaBean? Something in Tomcat configuration?
Please help me finding a solution!

Answer 1

You shouldn't install any s'ware to a directory whose name contains spaces. I'd move Tomcat out of those directories if I were you.
3) I've created the following simple JavaBean
(prova.java). It do nothing. I've compiled it (using
JcreatorLE ide) and I copied files in the following
directory:
"C:\Programmi\Apache Software Foundation\Tomcat
5.0\webapps\ROOT\ServiceDiscovery\WEB-INF\classes"This is a bad idea. Create a context for your own Web app by creating a directory under TOMCAT_HOME/webapps and put your stuff under that directory. Using ROOT isn't a good practice, IMO. Learn how to do it properly:
http://jakarta.apache.org/tomcat/tomcat-5.0-doc/appdev/index.html
>
4) prova.java 's code is very simple:
public class prova
public prova()
}Add a package statement to your JavaBean. Tomcat won't deal with servlets or JavaBeans that aren't in a package. The default package is insufficient.
>
5) Under the main Tomcat's directory
("C:\Programmi\Apache Software Foundation\Tomcat
5.0\webapps\ROOT") I've created a new directory
("ServiceDiscovery"). In this directory I've copied
the "WEB-INF" directory which was in the Tomcat's main
directory. The current directory state is:
C:\Programmi\Apache Software Foundation\Tomcat
5.0\webapps\ROOT\ServiceDiscovery
|
+--- WEB-INF (directory)
| |
| +--- classes (directory)
| | |
| | +--- org\apache\jsp\index_jsp.class
| | |
| | +--- prova.java
| | |
| | +--- prova.class
| |
| +--- lib (directory)
| |
| +--- web.xml
|
+--- index.jsp
I'd still recommend that each Web app have its own context. Putting your stuff in the Tomcat ROOT context is a bad idea. Better to learn a good habit now.
5) I've edited the following script at the beginning
(first line) of index.jsp:
"<jsp:useBean id="prova" class="prova" scope="session"
/>"
And how did that object get into session scope?
6) When I open Internet Explorer at the URL
"http://localhost:8080/ServiceDiscovery", Tomcat
server reply with this error message:
org.apache.jasper.JasperException:
/ServiceDiscovery/index.jsp(3,0) The value for the
useBean class attribute provami.prova is invalid.You've got a few problems. Add a package for starters. Reinstall Tomcat to a directory without spaces in its name. Create a new context for your Web app. Then come back if it still doesn't work.