java - display welcome messsage on browser using spring mvc -
here trying print message "welcome spring - mvc" on browser. not getting printed. here controller class handles request.
package org.spring.controller; import org.springframework.stereotype.controller; import org.springframework.ui.modelmap; import org.springframework.web.bind.annotation.requestmapping; import org.springframework.web.bind.annotation.requestmethod; @controller public class helloworldcontroller { @requestmapping(value="/",method=requestmethod.get) public string sayhello(model model){ model.addattribute("message", "welcome spring - mvc"); return "welcome"; } @requestmapping(value="/helloagain",method=requestmethod.get) public string sayhelloagain(modelmap model){ model.addattribute("message", "welcome again spring - mvc"); return "welcome"; } } here welcome.jsp , view displayed
<%@ page language="java" contenttype="text/html; charset=iso-8859-1" pageencoding="iso-8859-1"%>
<html> <head> <meta http-equiv="content-type" content="text/html; charset=iso-8859-1"> <title>helloworldxmlspring</title> </head> <body> <h1>welcome spring mvc</h1> <h3>${message}</h3> <h2>hiiiiiiiiiii..</h2> </body> </html >
here web.xml
<?xml version="1.0" encoding="utf-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/xmlschema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemalocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="webapp_id" version="3.1"> <display-name>helloworldxml</display-name> <welcome-file-list> <welcome-file>/web-inf/views/welcome.jsp</welcome-file> </welcome-file-list> <servlet> <servlet-name>dispatch</servlet-name> <servlet-class>org.springframework.web.servlet.dispatcherservlet</servlet-class> <init-param> <param-name>contextconfiglocation</param-name> <param-value>/web-inf/dispatch-servlet.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>dispatch</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app> here bean configuration file
<?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:context="http://www.springframework.org/schema/context" xsi:schemalocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd"> <context:component-scan base-package="org.spring.controller.helloworldcontroller"/> <bean class = "org.springframework.web.servlet.view.internalresourceviewresolver"> <property name="prefix"> <value>/web-inf/views/</value></property> <property name="suffix"> <value>.jsp</value></property> </bean> </beans> its printing
welcome spring mvc , hiiiiiiiiiii..
but model data sent servlet . i.e {message} not printing. reason?
@requestmapping(value="/",method=requestmethod.get) public modelandview sayhello(model model){ model.addattribute("message", "welcome spring - mvc"); return new modelandview("welcome"); } @requestmapping(value="/helloagain",method=requestmethod.get) public modelandview sayhelloagain(model model){ model.addattribute("message", "welcome again spring - mvc"); return new modelandview("welcome"); } in spring frameworkorg.springframework.ui.model designed adding attributes model. allows accessing overall model java.util.map. model attribute used data/information transfer barrier in spring web application.
org.springframework.web.servlet.modelandview holder both model , view in web mvc framework.this class merely holds both make possible controller return both model , view in single return value.
so best practice use return new modelandview("welcome"); or return new modelandview("welcome","data",model); , pass view name in controller. because return "welcome"; may fail add model data in view.
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