Tomcat cannot find my Java Class

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1

Hi, this problem has plagued me for a number of hours. I’ve googled looking for an answer, and still cannot figure this out.

This is a very simple JSP and Java class. I am just trying to access a java object from inside a jsp.

myjsp.jsp

<HTML>
<BODY BGCOLOR=“FDF5E6” >
<%!
MyClass data = new MyClass();
data.setUsername( “beagle” ); %>
<p>
Name is: <%= data.getUsername() %><br>
</BODY>
</HTML>

MyClass.java

public class MyClass {

String username;

public MyClass() {}

public void setUsername( String value )
{
    username = value;
}

public String getUsername() { return username; }

}

I have compiled MyClass to MyClass.class and placed it in ${CATALINA_HOME}/webapps/ROOT/WEB-INF/classes

I have stopped and started the tomcat server.

I have edited context.xml and added <Context reloadable=“true” >, to reload classes with a newer timestamp.

This all works if I put a package statement in. ie: in MyClass.java

package MyTest;

and in myjsp.jsp

MyTest.MyClass data = new MyTest.MyClass();

(and then store the class in ${CATALINA_HOME}/webapps/ROOT/WEB-INF/classes/MyTest

I would very much like to understand why the tomcat server cannot find my classes without having to access a packaged java class.

Thanks if anyone knows the secret to this!

When I do not have the package statement, and store my class in the classes directory, the error I get is:

org.apache.jasper.JasperException: Unable to compile class for JSP

An error occurred at line: 3 in the jsp file: /myjsp.jsp
Generated servlet error:
MyClass cannot be resolved to a type

An error occurred at line: 3 in the jsp file: /myjsp.jsp
Generated servlet error:
MyClass cannot be resolved to a type

An error occurred at line: 3 in the jsp file: /myjsp.jsp
Generated servlet error:
Syntax error on token(s), misplaced construct(s)

An error occurred at line: 3 in the jsp file: /myjsp.jsp
Generated servlet error:
Syntax error on token ““beagle””, delete this token

An error occurred at line: 7 in the jsp file: /myjsp.jsp
Generated servlet error:
data cannot be resolved
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:510)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:375)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

root cause

org.apache.jasper.JasperException: Unable to compile class for JSP

An error occurred at line: 3 in the jsp file: /myjsp.jsp
Generated servlet error:
MyClass cannot be resolved to a type

An error occurred at line: 3 in the jsp file: /myjsp.jsp
Generated servlet error:
MyClass cannot be resolved to a type

An error occurred at line: 3 in the jsp file: /myjsp.jsp
Generated servlet error:
Syntax error on token(s), misplaced construct(s)

An error occurred at line: 3 in the jsp file: /myjsp.jsp
Generated servlet error:
Syntax error on token ““beagle””, delete this token

An error occurred at line: 7 in the jsp file: /myjsp.jsp
Generated servlet error:

2

As far as I know, Tomcat no longer recognizes non-packaged classes in order to discourage sloppy programming.

I’m sure there’s some other, more technical, reason…

3

Do you have an import statement in your JSP? Your first line should look something like this:


<%@page import="com.me.MyClass"%>

If you don’t do that, your JSP doesn’t know to load that class for use on the page.

4

Okay, this is good to know. Since I don’t have a lot of experience working with Tomcat, it makes me think I’m missing something when I can’t get it to work. Thanks!

If you don’t do that, your JSP doesn’t know to load that class for use on the page.

I have used the import directive, but for my example, I was trying to get it to work without a package path. Importing com.me.MyClass would be a packaged class.

5