Binding complex object with forms

[osingh]

Hi Team,

I have the following form which I need to submit.

<form method="POST" action="registerUser.html">
<table border="0" cellspacing="5" cellpadding="0">
	<tr>
		<td>First Name :<input type="text" name="firstname"></td>
	</tr>
	<tr>
		<td>Last Name :<input type="text" name="lastname"></td>
	</tr>
	<tr>
		<td>Street :<input type="text" name="address.street"></td>
	</tr>
	<tr>
		<td>State :<input type="text" name="address.state"></td>
	</tr>
</table>
</form>

The data is validated and then then passed on the controller.

Configuration file

	<bean id="addressValidator" class="com.skyline.foundation.web.AddressValidator"/>

	<bean id="userRegistrationValidator" class="com.skyline.foundation.web.UserRegistrationValidator">
		<constructor-arg><ref bean="addressValidator"/></constructor-arg>
	</bean>

	<bean id="registerUserController"
		class="com.skyline.foundation.web.RegisterUserController">			
	    <property name="sessionForm"><value>true</value></property>
        <property name="commandName"><value>user</value></property>
        <property name="commandClass"><value>com.skyline.foundation.model.User</value></property>
        <property name="validator"><ref bean="userRegistrationValidator"/></property>
        <property name="formView"><value>registerUser</value></property>
        <property name="successView"><value>registerSuccess.htm</value></property>
        <property name="userService"><ref bean="userService" /></property>
	</bean>

The user object is as defined below and has the setter and getter for the attributed

public class User implements Serializable, Comparable {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	private Long id = null;
	private int version;
	private String firstname;
	private String lastname;
	private Address address;

The Address class is as below

	public class Address implements Serializable {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private String street;
	private String country;

When ever I am submitting my form I am getting the following exception

org.springframework.beans.NullValueInNestedPathException: Invalid property 'address' of bean class [com.skyline.foundation.model.User]: Value of nested property 'address' is null
	org.springframework.beans.BeanWrapperImpl.getNestedBeanWrapper(BeanWrapperImpl.java:419)
	org.springframework.beans.BeanWrapperImpl.getBeanWrapperForPropertyPath(BeanWrapperImpl.java:394)
	org.springframework.beans.BeanWrapperImpl.setPropertyValue(BeanWrapperImpl.java:600)
	org.springframework.beans.AbstractPropertyAccessor.setPropertyValue(AbstractPropertyAccessor.java:49)
	org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:74)
	org.springframework.validation.DataBinder.applyPropertyValues(DataBinder.java:517)
	org.springframework.validation.DataBinder.doBind(DataBinder.java:419)
	org.springframework.web.bind.WebDataBinder.doBind(WebDataBinder.java:147)
	org.springframework.web.bind.ServletRequestDataBinder.bind(ServletRequestDataBinder.java:108)
	org.springframework.web.servlet.mvc.BaseCommandController.bindAndValidate(BaseCommandController.java:369)
	org.springframework.web.servlet.mvc.AbstractFormController.handleRequestInternal(AbstractFormController.java:248)
	org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:153)
	org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:45)
	org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:820)
	org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:755)
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:396)
	org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:360)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

Please help me how to bind the form with a complex command object.

Regards
Om

[jglynn]

Your User constructor needs to instantiate an Address.

[osingh]

I have a constructor as well which is as below

public class User implements Serializable, Comparable {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	private Long id = null;
	private int version;
	private String firstname;
	private String lastname;
	private Address address;

	/**
	 * No-arg constructor for JavaBean tools.
	 */
	User() {
	}

	/**
	 * Full constructor.
	 */
	public User(String firstname, String lastname, Address address) {
		this.firstname = firstname;
		this.lastname = lastname;
		this.address = address;
	}

[Marten Deinum]

Your User constructor needs to instantiate an Address.

your constructor and Address declaration

private Address address;
User() {}

The rest should be easy to figure out by now....

[osingh]

	/**
	 * Full constructor.
	 */
	public User(String firstname, String lastname, Address address) {
		this.firstname = firstname;
		this.lastname = lastname;
		this.address = address;
	}

I already have a constructor with above defination

[Marten Deinum]

Well yeah you have BUT that one isn't used by yuor FormController. A new user object wil be created with a new User() (Spring uses reflection for that). So NO Address object is instantiated...

I suggest I readup on how the framework works, read chapter 13 of the reference guide and take a look at the javadoc.

[vivekdandale]

Instantiate Address in User bean.
EXample: private Address address = new Address();
Enjoy