To my knowledge, and according to instructions I’ve found (like this and this too), I need this in web.xml for Spring to work:
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
In my Wicket application class, I’d have:
public class MyApplication extends WebApplication {
@Override
protected void init() {
super.init();
addComponentInstantiationListener(new SpringComponentInjector(this));
}
@Override
public Class<? extends Page> getHomePage() {
return HelloWorldPage.class;
}
}
Problem is, whenever I have ContextLoaderListener in web.xml, Wicket doesn’t start. I just get 404 errors (or blank page), and console output like:
SEVERE: Error listenerStart
Jun 28, 2011 12:49:04 PM org.apache.catalina.util.SessionIdGenerator createSecureRandom
INFO: Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [1,973] milliseconds.
Jun 28, 2011 12:49:04 PM org.apache.catalina.core.StandardContext startInternal
SEVERE: Context [] startup failed due to previous errors
Jun 28, 2011 12:49:04 PM org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: The web application [] registered the JDBC driver [org.hsqldb.jdbc.JDBCDriver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
Jun 28, 2011 12:49:04 PM org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: The web application [] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
Jun 28, 2011 12:49:04 PM org.apache.catalina.startup.HostConfig deployDirectory
I’m using latest releases of both frameworks (Wicket 1.4.17 & Spring 3.0.5), and Tomcat 7 to run them on (the same thing happens with Tomcat 6). Also, I have the following jars in WEB-INF/lib. Something missing or too much?
antlr-2.7.6.jar log4j-1.2.16.jar spring-web-3.0.5.jar
commons-collections-3.1.jar mysql-connector-5.1.10.jar slf4j-api-1.6.1.jar
dom4j-1.6.1.jar spring-beans-3.0.5.jar slf4j-log4j12-1.6.1.jar
guava-r09.jar spring-context-3.0.5.jar wicket-1.4.17.jar
hibernate-3.6.5.jar spring-core-3.0.5.jar wicket-auth-roles-1.4.17.jar
hibernate-jpa-2.0-api-1.0.0.Final.jar spring-jdbc-3.0.5.jar wicket-datetime-1.4.17.jar
hsqldb.jar spring-orm-3.0.5.jar wicket-ioc-1.4.17.jar
javassist-3.12.0.GA.jar spring-test-3.0.5.jar wicket-spring-1.4.17.jar
jta-1.1.jar spring-transaction-3.0.5.jar wicketstuff-annotation-1.4.17.2.jar
The rest of the web.xml (I’ve tried setting up Wicket with both servlet and filter; makes no difference):
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
version="2.4">
<display-name>My App</display-name>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</context-param>
<context-param>
<param-name>configuration</param-name>
<param-value>development</param-value>
</context-param>
<filter>
<filter-name>MyApp</filter-name>
<filter-class>org.apache.wicket.protocol.http.WicketFilter</filter-class>
<init-param>
<param-name>applicationClassName</param-name>
<param-value>com.acme.MyApplication</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>MyApp</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
</web-app>
Googling around I found someone with the same problem, but no solutions.
Funny thing is, I’ve had Spring and Wicket working together nicely before, with pretty much identical setup. Any ideas?
Edit: Later on I realised the root problem here most likely was missing log configuration. In our case (using SLF4J with log4j), after adding proper configuration in
log4j.propertiesall kinds of warnings & errors logged by libraries became visible, even with Tomcat.I tried Jetty instead of Tomcat, and started getting better error messages. Turns out there were several libraries missing — stuff needed by some of the libraries I already used.
Some of the libs apparently require commons-logging, which I added. Next:
Added spring-asm. Next:
Added spring-aop. Next something a little less straight-forward:
Found discussion about aopalliance missing in Spring blog comments. Apparently it has been completely removed from spring-aop, and you need to get aopalliance.jar from sourceforge.
(I think this kind of swamp is Java EE at its worst: I don’t know what
spring-asmorspring-aoplet aloneaopalliancedo, but apparently I need them. :-P)So, added aopalliance.jar. Later I still needed to add spring-expression and cglib-2.2 (which comes with Hibernate).
After that, some problems with my Spring/Hibernate persistence layer configuration remain, but they are out of scope for this question. Otherwise Wicket & Spring now work nicely (e.g. for injecting service layer objects on Wicket pages).
I guess one moral of this is that in some cases Tomcat eats useful error messages and Jetty might be better for debugging. Also, using Maven would have probably helped with the dependency hell somewhat (but it’s not free of problems either).