Today we will create a Spring MVC based application that uses Freemarker FTL as view instead of JSP. This would give you a good insight in Spring MVC + Freemarker integration. The application is similar to previous tutorial’s User app, where a list of users will be displayed and also we can add new user.
The application is very simple:
- There is a table that displays user info like firstname, lastname.
- New user can be added via Add User form.
Below is the wireframe of our final freemarker based spring mvc 3 app.
So lets get started.
Things We Need
Before we starts with our Spring MVC 3 + FreeMarker example, we will need few tools.
- JDK 1.6 or above (download)
- Tomcat 6.x or above or any other container (Glassfish, JBoss, Websphere, Weblogic etc) (download)
- Eclipse 3.4.x or above (download)
- Spring MVC 3.1.2 or above (download)
- Freemarker JAR v2.3.15 or above(download)
Let us start with our Spring MVC based Freemarker application.
Step 1: Getting Started
Open Eclipse and goto File -> New -> Project and select Dynamic Web Project in the New Project wizard screen.
After selecting Dynamic Web Project, press Next.
Write the name of the project. For example Freemarker_SpringMVC_example. Once this is done, select the target runtime environment (e.g. Apache Tomcat v6.0). This is to run the project inside Eclipse environment. After this press Finish.
Once the project is created, you can see its structure in Project Explorer. This is how the project structure would look like when we finish the tutorial and add all source code.
Till this step, our basic Eclipse web project is ready. We will now add Spring MVC and Freemarker support to this project.
Step 2: Adding Spring MVC Support
First copy all required Spring MVC and supporting JAR files in WebContent > WEB-INF > lib folder. Create this folder if it does not exists. Don’t worry if you do not have these JARs. You can download the complete source code with JAR files at the end of this tutorial.
Next we change web.xml (deployment descriptor) and add Spring MVC support to it. If you do not know why we do this, I strongly recommends you to go through Spring 3 MVC Tutorial series.
Related: Spring 3 MVC hello world example
Update the web.xml with following code:
File: /WebContent/WEB-INF/web.xml
<?
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_3_0.xsd"
id
=
"WebApp_ID"
version
=
"3.0"
>
<
display-name
>Freemarker_SpringMVC_example</
display-name
>
<
welcome-file-list
>
<
welcome-file
>index.html</
welcome-file
>
<
welcome-file
>index.jsp</
welcome-file
>
</
welcome-file-list
>
<
servlet
>
<
servlet-name
>spring</
servlet-name
>
<
servlet-class
>
org.springframework.web.servlet.DispatcherServlet
</
servlet-class
>
<
load-on-startup
>1</
load-on-startup
>
</
servlet
>
<
servlet-mapping
>
<
servlet-name
>spring</
servlet-name
>
<
url-pattern
>*.html</
url-pattern
>
</
servlet-mapping
>
</
web-app
>
|
The above code in web.xml will map DispatcherServlet
with url pattern *.html
. One thing to note here is the name of servlet in <servlet-name>
tag in web.xml. Once the DispatcherServlet is initialized, it will look for a file name [servlet-name]-servlet.xml
in WEB-INF
folder of web application. In this example, the framework will look for file called spring-servlet.xml
.
Create a new file spring-servlet.xml
under /WebContent/WEB-INF/
folder. This is the spring configuration. Copy following code into it.
File: /WebContent/WEB-INF/spring-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:p
=
"http://www.springframework.org/schema/p"
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"
>
<!-- freemarker config -->
<
bean
id
=
"freemarkerConfig"
class
=
"org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer"
>
<
property
name
=
"templateLoaderPath"
value
=
"/WEB-INF/ftl/"
/>
</
bean
>
<!--
View resolvers can also be configured with ResourceBundles or XML files. If you need
different view resolving based on Locale, you have to use the resource bundle resolver.
-->
<
bean
id
=
"viewResolver"
class
=
"org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver"
>
<
property
name
=
"cache"
value
=
"true"
/>
<
property
name
=
"prefix"
value
=
""
/>
<
property
name
=
"suffix"
value
=
".ftl"
/>
</
bean
>
<
context:component-scan
base-package
=
"net.viralpatel"
/>
</
beans
>
|
In the above xml configuration file, we have defined a tag <context:component-scan>
. This will allow Spring to load all the components from package net.viralpatel
and all its child packages. This will load our UserController
class. Also we have defined a bean viewResolver
. We usesorg.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver
as view resolver. Also notice how we defined bean freemarkerConfig
. This defines Freemarker configuration, in our case just one property templateLoaderPath
; the path where we will store all our .ftl
template files.
Thus the bean viewResolver
will resolve the freemarker template view. Note that in our UserController class, we have return a view name “index”. This will be resolved to path /WEB-INF/ftl/index.ftl
byFreeMarkerViewResolver
.
Step 3: Create Spring MVC Controller
File: /src/net/viralpatel/UserController.java
package
net.viralpatel;
import
java.util.ArrayList;
import
java.util.List;
import
org.springframework.stereotype.Controller;
import
org.springframework.ui.ModelMap;
import
org.springframework.web.bind.annotation.ModelAttribute;
import
org.springframework.web.bind.annotation.RequestMapping;
import
org.springframework.web.bind.annotation.RequestMethod;
@Controller
public
class
UserController {
/**
* Static list of users to simulate Database
*/
private
static
List<User> userList =
new
ArrayList<User>();
//Initialize the list with some data for index screen
static
{
userList.add(
new
User(
"Bill"
,
"Gates"
));
userList.add(
new
User(
"Steve"
,
"Jobs"
));
userList.add(
new
User(
"Larry"
,
"Page"
));
userList.add(
new
User(
"Sergey"
,
"Brin"
));
userList.add(
new
User(
"Larry"
,
"Ellison"
));
}
/**
* Saves the static list of users in model and renders it
* via freemarker template.
*
* @param model
* @return The index view (FTL)
*/
@RequestMapping
(value =
"/index"
, method = RequestMethod.GET)
public
String index(
@ModelAttribute
(
"model"
) ModelMap model) {
model.addAttribute(
"userList"
, userList);
return
"index"
;
}
/**
* Add a new user into static user lists and display the
* same into FTL via redirect
*
* @param user
* @return Redirect to /index page to display user list
*/
@RequestMapping
(value =
"/add"
, method = RequestMethod.POST)
public
String add(
@ModelAttribute
(
"user"
) User user) {
if
(
null
!= user &&
null
!= user.getFirstname()
&&
null
!= user.getLastname() && !user.getFirstname().isEmpty()
&& !user.getLastname().isEmpty()) {
synchronized
(userList) {
userList.add(user);
}
}
return
"redirect:index.html"
;
}
}
|
The UserController is a simple Spring 3 MVC controller that handles request/response. We have created a private static List userList
which stores the user entries. Note that in ideal example you would like to read data from database. But for sake of simplicity we will stick to static List
There are two methods index()
and add()
, both mapped via @RequestMapping
annotation. The index() method will simply store the users list in model object and render “index” view (index.ftl). And the add() method gets the user details from html form and add it inside static List. Once the add() has added user, it simply redirects the request to /index.html which will render the user list.
Apart from the above UserController
class, we will also need a bean class User
which holds the user information like firstname, lastname etc.
File: /src/net/viralpatel/User.java
package
net.viralpatel;
public
class
User {
private
String firstname;
private
String lastname;
public
User() {
}
public
User(String firstname, String lastname) {
this
.firstname = firstname;
this
.lastname = lastname;
}
//Add Getter and Setter methods
}
|
Now add Freemarker view in your project.
Step 4: Create Freemarker Template Files
Create a new file index.ftl
under folder /WebContent/WEB-INF/ftl/
. Copy following content into it.
File: /WebContent/WEB-INF/ftl/index.ftl
<
html
>
<
head
><
title
>ViralPatel.net - FreeMarker Spring MVC Hello World</
title
>
<
body
>
<
div
id
=
"header"
>
<
H2
>
<
a
href
=
"http://viralpatel.net"
><
img
height
=
"37"
width
=
"236"
border
=
"0px"
src
=
"http://viralpatel.net/blogs/wp-content/themes/vp/images/logo.png"
align
=
"left"
/></
a
>
FreeMarker Spring MVC Hello World
</
H2
>
</
div
>
<
div
id
=
"content"
>
<
fieldset
>
<
legend
>Add User</
legend
>
<
form
name
=
"user"
action
=
"add.html"
method
=
"post"
>
Firstname: <
input
type
=
"text"
name
=
"firstname"
/> <
br
/>
Lastname: <
input
type
=
"text"
name
=
"lastname"
/> <
br
/>
<
input
type
=
"submit"
value
=
" Save "
/>
</
form
>
</
fieldset
>
<
br
/>
<
table
class
=
"datatable"
>
<
tr
>
<
th
>Firstname</
th
> <
th
>Lastname</
th
>
</
tr
>
<#list model["userList"] as user>
<
tr
>
<
td
>${user.firstname}</
td
> <
td
>${user.lastname}</
td
>
</
tr
>
</#list>
</
table
>
</
div
>
</
body
>
</
html
>
|
This is a simple FTL template file. We just iterate model["userList"] list in a loop and prints user’s firstname and lastname in table.
That’s All Folks
You may want to run the application see the result. I assume you have already configured Tomcat in eclipse. All you need to do:
Open Server view from Windows > Show View > Server. Right click in this view and select New > Server and add your server details.
To run the project, right click on Project name from Project Explorer and select Run as > Run on Server (Shortcut: Alt+Shift+X, R)
URL: http://localhost:8080/Freemarker_SpringMVC_example/index.html