Configure wicket with spring without xml - spring

Question

Is it possible to configure wicket with spring without using any xml files like web.xml???
Here is my already made and working configuration for spring+hibernate. I would llike to go with this direction and totally get rid of xml configuration files. Please help.
package com.rerp.common.init;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration.Dynamic;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.ContextLoaderListener;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.filter.HiddenHttpMethodFilter;
import org.springframework.web.servlet.DispatcherServlet;
public class Initializer implements WebApplicationInitializer {
#Override
public void onStartup(ServletContext servletContext) throws ServletException {
AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();
ctx.register(WebAppConfig.class);
servletContext.addListener(new ContextLoaderListener(ctx));
ctx.setServletContext(servletContext);
Dynamic servlet = servletContext.addServlet("dispatcher", new DispatcherServlet(ctx));
servlet.addMapping("/");
servlet.setLoadOnStartup(1);
// Allow to use Put and Delete method for REST architecture
registerHiddenFieldFilter(servletContext);
}
private void registerHiddenFieldFilter(ServletContext aContext) {
aContext.addFilter("hiddenHttpMethodFilter", new HiddenHttpMethodFilter()).addMappingForUrlPatterns(null ,true, "/*");
}
}
And WebAppConfig file
package com.rerp.common.init;
import java.util.Properties;
import javax.annotation.Resource;
import javax.sql.DataSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.orm.hibernate4.HibernateTransactionManager;
import org.springframework.orm.hibernate4.LocalSessionFactoryBean;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.view.JstlView;
import org.springframework.web.servlet.view.UrlBasedViewResolver;
#Configuration
#ComponentScan("com.rerp")
#EnableWebMvc
#EnableTransactionManagement
#PropertySource("classpath:application.properties")
public class WebAppConfig {
private static final String PROPERTY_NAME_DATABASE_DRIVER = "db.driver";
private static final String PROPERTY_NAME_DATABASE_PASSWORD = "db.password";
private static final String PROPERTY_NAME_DATABASE_URL = "db.url";
private static final String PROPERTY_NAME_DATABASE_USERNAME = "db.username";
private static final String PROPERTY_NAME_HIBERNATE_DIALECT = "hibernate.dialect";
private static final String PROPERTY_NAME_HIBERNATE_SHOW_SQL = "hibernate.show_sql";
private static final String PROPERTY_NAME_HIBERNATE_HBM2DDL_AUTO = "hibernate.hbm2ddl.auto";
private static final String PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN_SERVICES = "services.entitymanager.packages.to.scan";
private static final String PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN_COMMON = "common.entitymanager.packages.to.scan";
private static final String PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN_CMS = "cms.entitymanager.packages.to.scan";
#Resource
private Environment env;
#Bean
public DataSource dataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName(env.getRequiredProperty(PROPERTY_NAME_DATABASE_DRIVER));
dataSource.setUrl(env.getRequiredProperty(PROPERTY_NAME_DATABASE_URL));
dataSource.setUsername(env.getRequiredProperty(PROPERTY_NAME_DATABASE_USERNAME));
dataSource.setPassword(env.getRequiredProperty(PROPERTY_NAME_DATABASE_PASSWORD));
return dataSource;
}
#Bean
public LocalSessionFactoryBean sessionFactory() {
LocalSessionFactoryBean sessionFactoryBean = new LocalSessionFactoryBean();
sessionFactoryBean.setDataSource(dataSource());
//sessionFactoryBean.setPackagesToScan(env.getRequiredProperty(PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN));
sessionFactoryBean.setPackagesToScan(new String[] {
env.getRequiredProperty(PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN_SERVICES),
env.getRequiredProperty(PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN_COMMON),
env.getRequiredProperty(PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN_CMS)
});
sessionFactoryBean.setHibernateProperties(hibProperties());
return sessionFactoryBean;
}
private Properties hibProperties() {
Properties properties = new Properties();
properties.put(PROPERTY_NAME_HIBERNATE_DIALECT, env.getRequiredProperty(PROPERTY_NAME_HIBERNATE_DIALECT));
properties.put(PROPERTY_NAME_HIBERNATE_SHOW_SQL, env.getRequiredProperty(PROPERTY_NAME_HIBERNATE_SHOW_SQL));
properties.put(PROPERTY_NAME_HIBERNATE_HBM2DDL_AUTO, env.getRequiredProperty(PROPERTY_NAME_HIBERNATE_HBM2DDL_AUTO));
return properties;
}
#Bean
public HibernateTransactionManager transactionManager() {
HibernateTransactionManager transactionManager = new HibernateTransactionManager();
transactionManager.setSessionFactory(sessionFactory().getObject());
return transactionManager;
}
#Bean
public UrlBasedViewResolver setupViewResolver() {
UrlBasedViewResolver resolver = new UrlBasedViewResolver();
resolver.setPrefix("/WEB-INF/pages/");
resolver.setSuffix(".jsp");
resolver.setViewClass(JstlView.class);
return resolver;
}
}

Answer 1

You can get rid of web.xml if you are using servlet 3 or a newer version. See user guide at http://wicket.apache.org/guide/guide/single.html#helloWorld_2.
To know how to use Spring as dependency injector see example project https://github.com/bitstorm/Wicket-tutorial-examples/tree/master/SpringInjectionExample

Answer 2

Is it possible to configure wicket with spring without using any xml files like web.xml???
Yes, that's possible.
Wicket uses a javax.servlet.Filter called org.apache.wicket.protocol.http.WicketFilter to boot Wicket, whereas Spring MVC uses a Servlet instead of a Filter. Because Wicket uses a filter, it is able to process the request before Spring's DispatcherServlet does. WicketFilter will pass request through when they are not Wicket related, so that the DispatcherServlet gets a chance to handle the request.
This is the solution in code:
Add wicket-spring module to autowire beans
<dependency>
<groupId>org.apache.wicket</groupId>
<artifactId>wicket-spring</artifactId>
<version>8.5.0</version>
</dependency>
Add DispatcherServlet and WicketFilter to the ServletContext in your WebApplicationInitializer
public class Initializer implements WebApplicationInitializer {
#Override
public void onStartup(ServletContext servletContext) throws ServletException {
// Add WicketFilter
FilterRegistration.Dynamic wicketFilterRegistration = servletContext.addFilter("wicketFilter", WicketFilter.class);
wicketFilterRegistration.setInitParameter("applicationClassName", "springwickettest.MyWicketApplication");
wicketFilterRegistration.setInitParameter("filterMappingUrlPattern", "/*");
wicketFilterRegistration.addMappingForUrlPatterns(null, false, "/*");
// Create Spring context
AnnotationConfigWebApplicationContext springContext = new AnnotationConfigWebApplicationContext();
springContext.register(WebAppConfig.class);
// Add Spring Context to ServletContext
servletContext.addListener(new ContextLoaderListener(springContext));
springContext.setServletContext(servletContext);
// Create Spring Dispatcher servlet
ServletRegistration.Dynamic servlet = servletContext.addServlet("dispatcher", new DispatcherServlet(springContext));
servlet.addMapping("/*");
servlet.setLoadOnStartup(1);
// Allow to use Put and Delete method for REST architecture
registerHiddenFieldFilter(servletContext);
}
private void registerHiddenFieldFilter(ServletContext aContext) {
aContext.addFilter("hiddenHttpMethodFilter", new HiddenHttpMethodFilter()).addMappingForUrlPatterns(null ,true, "/*");
}
}
Add Spring injector to Wicket
public class MyWicketApplication extends WebApplication {
#Override
public Class<? extends WebPage> getHomePage() {
return HomePage.class;
}
#Override
public void init() {
super.init();
// Get the SpringContext from the servletContext
WebApplicationContext springContext = WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext());
getComponentInstantiationListeners().add(new SpringComponentInjector(this, springContext));
// Mount your pages
mountPage("/test", TestPage.class);
}
}