Spring MVC, creating a form support object from a request?

Question

I am using Spring MVC 2.5 and I am trying to get a JSTL form object to load from a GET request. I have Hibernate POJO as my supporting objects.

The request has one page directing to another page with the class identifier (primary key of the row). The request looks like "newpage.htm? Name = RowId". This happens on the page with the form support object,

The new page above loads the object fields into editable fields filled with existing row values. The idea is that you should be able to edit these fields and then save them back to the database.

The appearance of this page looks something like this.

<form:form commandName="thingie">
    <span>Name:</span>
    <span><form:input path="name" /></span>
    <br/>
    <span>Scheme:</span>
    <span><form:input path="scheme" /></span>
    <br/>
    <span>Url:</span>
    <span><form:input path="url" /></span>
    <br/>
    <span>Enabled:</span>
    <span><form:checkbox path="enabled"/></span>
    <br/>

    <input type="submit" value="Save Changes" />
</form:form>

This controller has

public class thingieDetailController extends SimpleFormController {

    public thingieDetailController() {    
        setCommandClass(Thingie.class);
        setCommandName("thingie");
    }

    @Override
    protected Object formBackingObject(HttpServletRequest request) throws Exception {
        Thingie thingieForm = (Thingie) super.formBackingObject(request);

        //This output is always null, as the ID is not being set properly
        logger.debug("thingieForm.getName(): [" + thingieForm.getName() + "]");
        //thingieForm.setName(request.getParameter("name"));
        SimpleDAO.loadThingie(thingieForm);

        return thingieForm;
    }

    @Override
    protected void doSubmitAction(Object command) throws Exception {            
        Thingie thingie = (Thingie) command;
        SimpleDAO.saveThingie(thingie);
    }
}

, ( ) . Hibernate , , .

org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect)

, , - , -, Stale Object, .

-, Spring MVC, , .

EDIT:
factory.

private static final SessionFactory sessionFactory;
private static final Configuration configuration = new Configuration().configure();

static {
    try {
        // Create the SessionFactory from standard (hibernate.cfg.xml) 
        // config file.
        sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();
    } catch (Throwable ex) {
        // Log the exception. 
        System.err.println("Initial SessionFactory creation failed." + ex);
        throw new ExceptionInInitializerError(ex);
    }
}

public static SessionFactory getSessionFactory() {
    return sessionFactory;
}

Answer 1

Spring MVC + , hibernate . Spring - DEFAULT. , ( ) . .

, - :

protected void initBinder(HttpServletRequest request, ServletRequestDataBinder binder) 
throws Exception {
 String[] allowedFields = {"name", "birthday"}
 binder.setAllowedFields(allowedFields);
}

EXPLICITLY ALLOWED , , , .

Answer 2

, , Hibernate, :

• Hibernate ( A) formBackingObject
• A, Thingie formBackingObject
• Thingie formBackingObject
• Thingie, A , Thingie .
• doSubmitAction, Thingie
• Hibernate ( B)
• Thingie ( A), B

Hibernate A , , . , , .

formBackingObject , . , , , , .

, ; Record ). DAO Record, RecordDao. , UpdateRecordCommand, . UpdateRecordCommand /:

public class UpdateRecordCommand {
  // Row ID of the record we want to update
  private int rowId;
  // New name
  private int String name;
  // New scheme
  private int String scheme;
  // New URL
  private int String url;
  // New enabled flag
  private int boolean enabled;

  // Getters and setters left out for brevity
}

, :

<form:form commandName="update">
  <span>Name:</span>
  <span><form:input path="name" /></span><br/>
  <span>Scheme:</span>
  <span><form:input path="scheme" /></span><br/>
  <span>Url:</span>
  <span><form:input path="url" /></span><br/>
  <span>Enabled:</span>
  <span><form:checkbox path="enabled"/></span><br/>
  <form:hidden path="rowId"/>
  <input type="submit" value="Save Changes" />
</form:form>

, formBackingObject doSubmitAction.

public class UpdateRecordController extends SimpleFormController {

  private RecordDao recordDao;

  // Setter and getter for recordDao left out for brevity

  public UpdateRecordController() {    
      setCommandClass(UpdateRecordCommand.class);
      setCommandName("update");
  }

  @Override
  protected Object formBackingObject(HttpServletRequest request)
      throws Exception {
    // Use one of Spring utility classes to cleanly fetch the rowId
    int rowId = ServletRequestUtils.getIntParameter(request, "rowId");

    // Load the record based on the rowId paramrter, using your DAO
    Record record = recordDao.load(rowId);

    // Populate the update command with information from the record
    UpdateRecordCommand command = new UpdateRecordCommand();

    command.setRowId(rowId);
    command.setName(record.getName());
    command.setScheme(record.getScheme());
    command.setUrl(record.getUrl());
    command.setEnabled(record.getEnabled());

    // Returning this will pre-populate the form fields
    return command;
  }

  @Override
  protected void doSubmitAction(Object command) throws Exception {
    // Load the record based on the rowId in the update command
    UpdateRecordCommand update = (UpdateRecordCommand) command;
    Record record = recordDao.load(update.getRowId());

    // Update the object we loaded from the data store
    record.setName(update.getName());
    record.setScheme(update.getScheme());
    record.setUrl(update.getUrl());
    record.setEnabled(update.setEnaled());

    // Finally, persist the data using the DAO
    recordDao.save(record);
  }
}

Answer 3

. DAO Hibernate, Hibernate. Merge() update(). , .

Answer 4

, , name = rowId - . , , . DAO .

. , .