Receiving an array of Object from a web form using Spring framework

Question

Hi,

I have a form JSP web page, this form contains multiple instances of the same Java object, I am using Java Spring Framework to control the "communication" with the controller and the view.

My problem is that i would like to be able to receive from the view a simple array containing the instances of my objects wich are currently on the page (on wich were probably modified).

When i want a specific kind of item, I usually just name it in my controller's method declaration, however for an array (or any Collection), this won't work.

so something like:

@RequestMapping
public String edit(...SomeObject[] objectName, ...){
}

would just return me an error, i can however receive an array of String, so this works:

@RequestMapping
public String edit(...String[] objectString, ...){
}

the goal would be to be able to make Spring automatically map the object thanks for your answers!

Answer 1

This is certainly possible; while I've not done it using @RequestMapping, I know that you can retrieve a collection it can be done with a "command" object (or @ModelAttribute)

Define a POJO with a collection attribute as your command

public class FooCommand {
    private List<String> myCollection;
    // Getter & Setter
}

Then access it in your controller

@RequestMapping(value = "/foo", method = RequestMethod.POST)
public String processSubmit(@ModelAttribute("fooCommand") FooCommand fooCmd) {
    // do stuff with fooCmd.getMyCollection() 
}

That make any sense?

Answer 2

Spring does not know how to create your custom object from a String so you will need to create your own PropertyEditor for your custom object.

Chapter 5 of the Spring Reference explains data binding and there is an example in Chapter 13 of how to register custom property editors in your controller.