Spring//JSP//Form Handling - Using @ModelAttribute on String

Question

i am working on a Spring WebApplication. I have a Form with just one input, a textline. I want to get that text and use it somewhere else.

So the question is pretty simple: Is there any way, i can use @ModelAttribute String text on the controller method to avoid using a helper class?

So i want to do this:

  @RequestMapping(value="/url", method = RequestMethod.POST)
         public String handler(@ModelAttribute("inputtext") String inputtext, Model model)
        {
            sout(inputtext);
}

With a form like this:

    <form:form method="POST" action="url" commandName="inputtext">
   <table>
    <tr>
        <td><form:label path="???">The text</form:label></td>
        <td><form:input path="???"/></td>
    </tr>
    <tr>
        <td colspan="2">
            <input type="submit" value="Submit"/>
        </td>
    </tr>
</table>  
</form:form>

If that's possible, what would i use for "path"?

Thanks!

Fevly Pallar · Accepted Answer · 2016-01-20 11:08:19Z

4

Your question isn't clear, but the path= is intended to set property to a model class where your form get bound to. If you don't do any binding activities from that form to a model class, instead of you just want to pass the string, then don't use @ModelAttribute but @RequestParam instead,

@RequestMapping(value="/url", method = RequestMethod.POST)
public ModelAndView takeTheString( @RequestParam("inputtext") String inputtext) {    
           String temp_input =inputtext; 

       // By "sout" you mean "System.out.println()" right?
        System.out.println(temp_input );
    }

or with request object

@RequestMapping(value="/url", method = RequestMethod.POST)
public ModelAndView takeTheString(HttpServletRequest request, HttpServletResponse response) {               
          String temp_input =request.getParameter("inputtext"); 
           System.out.println(temp_input );   
    }

And The @ModelAttribute is supposed to annotated to a bound model like :

@ModelAttribute("userForm") UserBean user

This user is what I meant by the model class.

As requested under comment :

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">
    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>*.html</url-pattern>
    </servlet-mapping>
</web-app>

springmvc-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:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans 
                           http://www.springframework.org/schema/beans/spring-beans-4.0.xsd 
                           http://www.springframework.org/schema/context
                           http://www.springframework.org/schema/context/spring-context-4.0.xsd
                           http://www.springframework.org/schema/mvc 
                           http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">
    <context:component-scan base-package="com" />
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/pages/" />
        <property name="suffix" value=".jsp" />
    </bean>
</beans>

index.jsp :

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
        <form action="output.html" method="post">
            <input type="text" name="yourtext" value="">
            <input type="submit"  value="go">           
        </form>
    </body>
</html>

output.jsp :

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
       text = ${name}     
    </body>
</html>

InputController.java :

package com.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class InputController {
    @RequestMapping(value = "/output", method = RequestMethod.POST)
    public ModelAndView takeTheString(@RequestParam("yourtext") String name) {   
        System.out.println("String you've passed = "+name);
       return new ModelAndView("output", "name", name);
    }
}

edited Jan 20, 2016 at 11:08

answered Dec 31, 2015 at 20:23

Fevly Pallar

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5 Comments

Heady Over a year ago

Hello and thank you for your answer. I think you got my question right :) I already thought about using @RequestParam but i do not understand what to do in the JSP then. As far as i understand @RequestParam gets Parameters from the URL right? So how do i pass the contents of my input field to the Controller? (And sout = System.out.println() yes :) )

Fevly Pallar Over a year ago

If there's no binding activity (that you mean by helper class), then don't use <form:..> prefix in front of those tags , just use normal HTML tags, ex: <input type="text" name="myname" value="" /> , then in controller catch it up with @RequestParam("myname") String myName then output this myName (note that the ouput is shown in server's console, Tomcat, Glassfish or whatever you're using there), because if you use <form:..> hence the "path=" is mandatory, while no binding there (since the path= has to refer the binder class's attribute ).

Heady Over a year ago

Thank you.. Well that's quite simple after all :D For some reason i just never thought about not using the <form:..>. If you want you can post that as answer/add that to your answer so i can mark it.

Fevly Pallar Over a year ago

Alright, deal taken :P. There will be 2 outputs (one is in server's console and another one is in output.jsp page), and done.. , you're welcome.

Heady Over a year ago

Wow now you really earned that with your detailed answer ;)

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