user9634982 :
I recently configured spring based maven project and I just want to replace all my XML (except POM) with java. I explore a lot of articles and docs regarding this, But, the reason I am here is, I have doubts which I think to be get resolved by you people.
As we know, every dynamic web project has single XML, which is called web.xml in absence of a framework.
Now If we integrate some framework say Struts, Spring, ORM etc. It is necessary to configure those also, so we write another XML config file.
I configured spring project so I have one deployment descriptor,application-context, and dispatcher servlet.
WEB.XML
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
version="3.1">
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/app-ctx.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>2</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
<welcome-file-list>
<welcome-file>redirect.jsp</welcome-file>
</welcome-file-list>
</web-app>
app-ctx.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:flow="http://www.springframework.org/schema/webflow-config"
xmlns:jee="http://www.springframework.org/schema/jee"
xmlns:jms="http://www.springframework.org/schema/jms"
xmlns:lang="http://www.springframework.org/schema/lang"
xmlns:osgi="http://www.springframework.org/schema/osgi"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/webflow-config
http://www.springframework.org/schema/webflow-config/spring-webflow-config-2.0.xsd
http://www.springframework.org/schema/jee
http://www.springframework.org/schema/jee/spring-jee.xsd
http://www.springframework.org/schema/jms
http://www.springframework.org/schema/jms/spring-jms.xsd
http://www.springframework.org/schema/lang
http://www.springframework.org/schema/lang/spring-lang.xsd
http://www.springframework.org/schema/osgi
http://www.springframework.org/schema/osgi/spring-osgi.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/util
http://www.springframework.org/schema/util/spring-util.xsd">
<context:component-scan base-package="com.mzk.mavenproject1"/>
<!-- <bean id="propertyConfigurer"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"
p:location="/WEB-INF/config_local.properties" />-->
</beans>
dispatcher-servlet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:c="http://www.springframework.org/schema/c"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:flow="http://www.springframework.org/schema/webflow-config"
xmlns:jee="http://www.springframework.org/schema/jee"
xmlns:jms="http://www.springframework.org/schema/jms"
xmlns:lang="http://www.springframework.org/schema/lang"
xmlns:osgi="http://www.springframework.org/schema/osgi"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/webflow-config
http://www.springframework.org/schema/webflow-config/spring-webflow-config-2.0.xsd
http://www.springframework.org/schema/jee
http://www.springframework.org/schema/jee/spring-jee.xsd
http://www.springframework.org/schema/jms
http://www.springframework.org/schema/jms/spring-jms.xsd
http://www.springframework.org/schema/lang
http://www.springframework.org/schema/lang/spring-lang.xsd
http://www.springframework.org/schema/osgi
http://www.springframework.org/schema/osgi/spring-osgi.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/util
http://www.springframework.org/schema/util/spring-util.xsd">
<mvc:resources mapping="/resources/**" location="/resources/" cache-period="31556926" />
<context:component-scan base-package="com.mzk.mavenproject1"/>
<mvc:annotation-driven content-negotiation-manager="contentNegotiationManager"/>
<bean id="contentNegotiationManager" class="org.springframework.web.accept.ContentNegotiationManagerFactoryBean">
<!--Turn off working out content type based on URL file extension, should fall back to looking at the Accept headers-->
<property name="favorPathExtension" value="false" />
</bean>
<!-- 2. HandlerMapping : Used default handler mapping internally -->
<!-- 3. ViewResolver -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/"/>
<property name="suffix" value=".jsp"/>
</bean>
</beans>
CONFUSION:
I am confused to know that, exactly how java many classes we need to replace the same. We need three java classes or the two classes are enough?
because, a lot of articles demonstrated the two java classes, which replace web.xml and dispatcher-servlet.xml, so what about app-ctx.xml?
EDITS:
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addRedirectViewController("/", "home");
}
OR
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("home");
}
CONTROLLER CLASS
@Controller
public class HomeController {
@RequestMapping(value="/")
public ModelAndView showhomePage() {
ModelAndView mav = new ModelAndView("home");
mav.addObject("successMsg", "Congratulations! Your Cortana is Properly congigured");
return mav;
}
}
I also do one trick, I created a global index.jsp, and specify only one scriptlet which will redirect the request to the Controller by using `sendRedirect().
LIKE
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("forward:/index.jsp");
}
No snippet work for me, every time I am facing 404, something I am missing i think?
cgrim :
If I understand it well you want to get rid of all XML configurations.
Then at first you have to implement WebApplicationInitializer which replaces web.xml config file. You can do it like this:
public class CustomWebAppInitializer implements WebApplicationInitializer {
@Override
public void onStartup(ServletContext servletContext) throws ServletException {
AnnotationConfigWebApplicationContext rootContext = new AnnotationConfigWebApplicationContext();
rootContext.register(RootConfig.class);
ContextLoaderListener contextLoaderListener = new ContextLoaderListener(rootContext);
servletContext.addListener(contextLoaderListener);
AnnotationConfigWebApplicationContext webContext = new AnnotationConfigWebApplicationContext();
webContext.register(MvcConfig.class);
DispatcherServlet dispatcherServlet = new DispatcherServlet(webContext);
ServletRegistration.Dynamic dispatcher = servletContext.addServlet("dispatcher", dispatcherServlet);
dispatcher.setLoadOnStartup(1);
dispatcher.addMapping("/");
}
}
Another step is to implement Spring configuration for root context which replaces app-ctx.xml:
@Configuration
@EnableWebMvc
@ComponentScan({"com.mzk.mavenproject1.service", "com.mzk.mavenproject1.model"})
public class RootConfig {
// ... provide another custom beans when needed
}
And the last step is to implement configuration for MVC which replaces dispatcher-servlet.xml:
@Configuration
@EnableWebMvc
@ComponentScan("com.mzk.mavenproject1.controller")
public class MvcConfig extends WebMvcConfigurerAdapter {
@Bean
ViewResolver internalViewResolver() {
InternalResourceViewResolver resolver = new InternalResourceViewResolver();
resolver.setPrefix("/WEB-INF/views/");
resolver.setSuffix(".jsp");
return resolver;
}
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
registry.addResourceHandler("/resources/**").addResourceLocations("/resources/");
}
// ... provide another custom beans when needed
}
Regarding of your question about classes count - yes, you can do it only by two classes: CustomWebAppInitializer and MvcConfig and have only one context for everything.
CustomWebAppInitializer.onStartup() method body will then look like:
AnnotationConfigWebApplicationContext webContext = new AnnotationConfigWebApplicationContext();
webContext.register(MvcConfig.class);
ContextLoaderListener contextLoaderListener = new ContextLoaderListener(webContext);
servletContext.addListener(contextLoaderListener);
DispatcherServlet dispatcherServlet = new DispatcherServlet(webContext);
ServletRegistration.Dynamic dispatcher = servletContext.addServlet("dispatcher", dispatcherServlet);
dispatcher.setLoadOnStartup(1);
dispatcher.addMapping("/");