Unable to retrieve value sent from controller to view in spring mvc
Question
I am new to Spring MVC. I am writing a simple maven web project to display a hello world on view when it is invoked. In addition to this I am using apache tomcat 7.
I am following this
The Controller is getting invoked and I am able to set and print the modelmap.
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>springmvc</groupId>
<artifactId>demo</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>demo Maven Webapp</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.3.4.RELEASE</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
</dependencies>
<build>
<finalName>demo</finalName>
</build>
web.xml
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<servlet>
<servlet-name>HelloWeb</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>HelloWeb</servlet-name>
<url-pattern>*.action</url-pattern>
</servlet-mapping>
</web-app>
HelloWeb-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:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">
<mvc:annotation-driven />
<context:component-scan base-package="com.tutorialpoint" />
<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/hello/" />
<property name="suffix" value=".jsp" />
</bean>
</beans>
HelloController
package com.tutorialpoint;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
@Controller
@RequestMapping("/hello")
public class HelloController {
public HelloController(){
System.out.println("hiii");
}
@RequestMapping(method = RequestMethod.GET)
public String printHello(Model model){
System.out.println("this is controller");
model.addAttribute("testvalue", "Hello World!!");
System.out.println(model.toString());
return "output";
}
}
Output.jsp
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Output</title>
</head>
<body>
<p>This is output jsp page message is </p> ${testvalue}
</body>
</html>
But on resulting view(output.jsp) I am unable to fetch the value. I tried
- using spring core tag in jsp
- using the c:out tag
- putting maven dependency for jstl
Thanks in advance.
Edit - adding output.jsp screen shot
3 answers
solution1
4 ACCPTED 2016-12-20 09:09:35
If you want to use EL you need to declare your deployment descriptor (web.xml) as Servlet 2.4 or higher. As you use Tomcat 7 which supports Servlet 3.0 I'd recommend you to use that version.
You can achieve it by changing your opening bracket in web.xml to this:
<web-app version="3.0"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
If that hasn't resolved your problem try to include below directive in your view:
<%@ page isELIgnored="false" %>
Hope it helped.
solution2
3 2016-12-20 09:39:15
Here the problem is with the web.xml header
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
Change it to the following.
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
You don't need to add <%@ page isELIgnored="false" %> to every page instead change the web.xml header once.
solution3
2 2016-12-20 09:08:11
It will not work, as you are modifying the modal in controller and then moving to new view altogether which will have its own model . Hence any change you do will be nullified .
I would recommend you to use flash attribute facility of Spring MVC by adding RedirectAttributes in your controller method as follows,
@RequestMapping(method = RequestMethod.GET)
public String printHello(Model model, RedirectAttributes redir){
System.out.println("this is controller");
// model.addAttribute("testvalue", "Hello World!!");
redir.addFlashAttribute("testvalue", "Hello World!!");
System.out.println(model.toString());
return "redirect:/output";
}
Or Create a new ModelAndView and return it,
@RequestMapping(method = RequestMethod.GET)
public ModelAndView printHello(Model model){
ModelAndView model= new ModelAndView("output");
System.out.println("this is controller");
model.addAttribute("testvalue", "Hello World!!");
System.out.println(model.toString());
return model;
}
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