In this example, we will learn the usage of hidden value in a Simple Spring MVC Form using Springs tag library. We will learn how to use the <form:hidden>. Here we will create a Spring MVC form with a hidden value, when the user submits the form we will retrieve the hidden value which is passed from the form
In Spring MVC we will use <form:hidden> tag to render a hidden field
<form:hidden path="hiddenMessage" value="Hello JavaInterviewPoint"/>
Which produces the below HTML code.
<input id="hiddenMessage" name="hiddenMessage" value="Hello JavaInterviewPoint" type="hidden"/>
Folder Structure :
- Create a Dynamic Web Project SpringMVCFormHandling and create a package for our src files “com.javainterviewpoint“
- Place the Spring 3 jar files under WEB-INF/Lib
commons-logging-1.1.1.jar
log4j-1.2.16.jar
slf4j-api-1.7.5.jar
slf4j-log4j12-1.7.5.jar
hibernate-validator-4.2.0.Final.jar
spring-aspects-3.2.4.RELEASE.jar
spring-beans-3.2.4.RELEASE.jar
spring-context-3.2.4.RELEASE.jar
spring-core-3.2.4.RELEASE.jar
spring-expression-3.2.4.RELEASE.jar
spring-web-3.2.4.RELEASE.jar
spring-webmvc-3.2.4.RELEASE.jar
validation-api-1.1.0.Final.jar
jstl-1.1.2.jar - Create the Java classes HiddenValue_Controller.java and HiddenValueBean.java under com.javainterviewpoint folder.
- Place the SpringConfig-servlet.xml and web.xml under the WEB-INF directory
- View files SpringMVC_HiddenValueExample.jsp and hiddenvalue_Success.jsp are put under the sub directory under WEB-INF/Jsp
Controller
HiddenValue_Controller.java
-
- The DispatcherServlet mapping which we make in the web.xml will delegate all the request to our HiddenValue_Controller as we have annotated it with @Controller annotation.
- We use the @RequestMapping annotation to map each of the requests which we get to individual methods. Our controller has two methods initializeForm() and processForm().
- The firstMethod (initializeForm) will take the user to the “SpringMVC_HiddenValueExample” which is our view component with form backing object HiddenValueBean.
- The Second method (processForm) will get called when the user submits the form. The hidden message will be passed to the “hiddenvalue_Success” page.
import java.util.Map;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class HiddenValue_Controller {
@RequestMapping("/HiddenValueExample")
public String initializeForm(Map model) {
HiddenValueBean hb = new HiddenValueBean();
model.put("hb", hb);
return "SpringMVC_HiddenValueExample";
}
@RequestMapping("/processHiddenValue")
public String processForm(@ModelAttribute("hb") HiddenValueBean hb) {
System.out.println("Validation Passed");
System.out.println(">>>>" + hb.getHiddenMessage());
return "hiddenvalue_Success";
}
}
Model
HiddenValueBean.java
Here HiddenValueBean acts as a Model which has “hiddenMessage” property to store the hidden value which we pass from the view.
public class HiddenValueBean
{
String hiddenMessage;
public String getHiddenMessage()
{
return hiddenMessage;
}
public void setHiddenMessage(String hiddenMessage)
{
this.hiddenMessage = hiddenMessage;
}
}
View
SpringMVC_HiddenValueExample.jsp
Our view component has a hidden value tag generated using the Spring form tag library, which will be passed to the controller when the user submits the form
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%> <%@ taglib uri="http://www.springframework.org/tags/form" prefix="form" %> <!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>Insert title here</title> </head> <body> <form:form method="post" action="processHiddenValue" commandName="hb"> <form:hidden path="hiddenMessage" value="Hello JavaInterviewPoint"></form:hidden> <input type="submit" value="Submit Hidden Value"> </form:form> </body> </html>
hiddenvalue_Success.jsp
<%@ 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>Insert title here</title>
</head>
<body>
<h2>Hidden Value passed : ${hb.hiddenMessage}</h1>
</body>
</html>
Configurations
web.xml
The web.xml has everything about the application that a server needs to know, which is placed under the WEB-INF directory. <servlet-name> contains the name of the SpringConfiguration, when the DispatcherServlet is initialized the framework will try to load a configuration file “[servlet-name]-servlet.xml” under the WEB-INF directory.
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5"> <display-name>SpringMVCFormHandling</display-name> <welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>index.jsp</welcome-file> <welcome-file>default.html</welcome-file> <welcome-file>default.htm</welcome-file> <welcome-file>default.jsp</welcome-file> </welcome-file-list> <servlet> <servlet-name>SpringConfig</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>SpringConfig</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>
SpringConfig-servlet.xml
- The SpringConfig-servlet.xml is also placed under the WEB-INF directory.
- <context:component-scan> will let the Spring Container to search for all the annotation under the package “com.javainteriviewpoint”.
- <mvc:annotation-driven/> annotation will activate the @Controller, @RequestMapping, @Valid etc annotations.
- The view is resolved through “org.springframework.web.servlet.view.InternalResourceViewResolver” which searches for the jsp files under the /WEB-INF/Jsp/ directory.
- Resource Bundle is accessed through the “org.springframework.context.support.ResourceBundleMessageSource” through its property “basename” which has the value “props”, and hence our property file should “props.properties”
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 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"> <context:component-scan base-package="com.javainterviewpoint" /> <mvc:annotation-driven /> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/Jsp/" /> <property name="suffix" value=".jsp" /> </bean> <bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource"> <property name="basename" value="props"></property> </bean> </beans>
Lets run our application
Now lets run our application, do a clean build and deploy the application in the Server
Hit on the url “http://localhost:8080/SpringMVCFormHandling/HiddenValueExample”
Upon submission of the form, success page will be rendered to the user
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