In this example you
will see how to populate the form with dynamic values. Here is the user
registration form.
<%@ taglib uri="http://www.springframework.org/tags/form"
prefix="form"%>
<html>
<head>
<title>Registration
Page</title>
</head>
<body>
<form:form method="POST" commandName="user">
<table>
<tr>
<td>User Name :</td>
<td><form:input path="name" /></td>
</tr>
<tr>
<td>Password :</td>
<td><form:password path="password" /></td>
</tr>
<tr>
<td>Gender :</td>
<td>
<form:radiobutton path="gender" value="M" label="M" />
<form:radiobutton path="gender" value="F" label="F" />
</td>
</tr>
<tr>
<td>Country :</td>
<td>
<form:select path="country">
<form:option value="0" label="Select" />
<form:options items="${countryList}" itemValue="countryId"itemLabel="countryName" />
</form:select>
</td>
</tr>
<tr>
<td>About you :</td>
<td><form:textarea path="aboutYou" /></td>
</tr>
<tr>
<td>Community :</td>
<td><form:checkboxes path="communityList" items="${communityList}"itemValue="key" itemLabel="value" /></td>
</tr>
<tr>
<td></td>
<td>
<form:checkbox path="mailingList" label="Would you like to join our
mailinglist?" />
</td>
</tr>
<tr>
<td colspan="2"><input type="submit" value="Register"></td>
</tr>
</table>
</form:form>
</body>
</html>
Here we populate the
countryList and the communityList from the back-end. The items attribute holds the collection. The itemValue and itemLabel attributes holds the key and value respectively. ItemLabelis the one that
will be displayed to the user and itemValue is the one that will be passed when
that particular item is selected.
Here we have three
domain objects User, Country and Community. The User object is the one that is
associated with the form.
package com.vaannila.domain;
import java.util.List;
@SuppressWarnings("unchecked")
public class User {
private String name;
private String
password;
private String gender;
private String country;
private List
countryList;
private String
aboutYou;
private String[]
community;
private List
communityList;
private Boolean
mailingList;
public String
getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String
getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String
getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public String
getCountry() {
return country;
}
public void setCountry(String country) {
this.country = country;
}
public List
getCountryList() {
return countryList;
}
public void setCountryList(List countryList) {
this.countryList =
countryList;
}
public String
getAboutYou() {
return aboutYou;
}
public void setAboutYou(String aboutYou) {
this.aboutYou = aboutYou;
}
public String[]
getCommunity() {
return community;
}
public void setCommunity(String[] community) {
this.community =
community;
}
public List
getCommunityList() {
return communityList;
}
public void setCommunityList(List communityList) {
this.communityList =
communityList;
}
public Boolean
getMailingList() {
return mailingList;
}
public void setMailingList(Boolean mailingList) {
this.mailingList =
mailingList;
7}
7
7
7}
The User object has
a countryList and communityList to hold the list of countries and communities
respectively.
The countryList
contains a list of Country objects.
ackage com.vaannila.domain;
public class Country {
private int countryId;
private String
countryName;
public Country(int countryId, String countryName)
{
this.countryId=countryId;
this.countryName=countryName;
}
public int getCountryId() {
return countryId;
}
public void setCountryId(int countryId) {
this.countryId =
countryId;
}
public String
getCountryName() {
return countryName;
}
public void setCountryName(String countryName) {
this.countryName =
countryName;
}
}
The countryId is
used to refer the country in the back-end and the countryName to dispaly the
country in the front-end.
Similarly the
communityList contains a list of community objects.
package com.vaannila.domain;
public class Community {
private String key;
private String value;
public Community(String
key, String value)
{
this.key = key;
this.value = value;
}
public String getKey()
{
return key;
}
public void setKey(String key) {
this.key = key;
}
public String
getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
}
Here the value is the one that will be dispalyed in the front-end and the key is the one that will be used in the back-end.
In the controller class you need to
override the referenceData() method. In this method you can set all the default values that should be
loaded when the form is displayed to the user. This method will be called
automatically.
package com.vaannila.web;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.SimpleFormController;
import com.vaannila.domain.User;
import com.vaannila.service.UserService;
@SuppressWarnings("deprecation")
public class UserController extends SimpleFormController {
private UserService
userService;
public UserController()
{
setCommandClass(User.class);
setCommandName("user");
}
public void setUserService(UserService userService) {
this.userService =
userService;
}
@SuppressWarnings("unchecked")
@Override
protected Map referenceData(HttpServletRequest request) throws Exception {
Map referenceData = new HashMap();
referenceData.put("countryList", userService.getAllCountries());
referenceData.put("communityList", userService.getAllCommunities());
return referenceData;
}
@Override
protected ModelAndView onSubmit(Object command) throws Exception {
User user = (User) command;
userService.add(user);
return new ModelAndView("userSuccess","user",user);
}
}
In the
referenceData() method we first create a HashMap and add the countryList and
the communityList to it. This method will be called before the form is rendered
so the list will be populated before that.
When you run the example you will see
the user registration form. On submitting the form theuserSuccess.jsp page will be displayed. In the userSuccess.jsp page we use jstl tags to display the details.
<%@ taglib uri="http://java.sun.com/jsp/jstl/core"
prefix="c" %>
<html>
<head>
<title>Success Page</title>
</head>
<body>
User Details
<hr>
User Name : <c:out value="${user.name}"></c:out>
Gender :
<c:out value="${user.gender}"></c:out>
Country : <c:out value="${user.country}"></c:out>
About You : <c:out value="${user.aboutYou}"></c:out>
Community :
<c:forEach var="community" items="${user.communityList}" >
<c:out value="${community}"></c:out>
</c:forEach>
Mailing List: <c:out value="${user.mailingList} "></c:out>
</body>
</html>
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