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JSF2: selectOneMenu with custom selectItems: all items are selected

开发者 https://www.devze.com 2023-01-21 22:07 出处:网络
Thanks to some great articles here, I\'ve been able to build a <h:selectOneMenu /> with selectItems containing objects. After providing a custom FacesConverter and fixing the missing equals()/ha

Thanks to some great articles here, I've been able to build a <h:selectOneMenu /> with selectItems containing objects. After providing a custom FacesConverter and fixing the missing equals()/hashcode() methods, I am able to use it to change the property of the backing bean and write it out to the DB.

The only weird thing is that all HTML <option /> elements of the <select />-element are checked="checked"! In other words: the <h:selectOneMenu /> does not reflect the current value of the bound property!

Details:

Store.java

@Entity
public class Store {
  private Long id;
  private String name;

  @ManyToOne
  private Category category;

  // getters, setters, equals, hashcode
}

Category.java

@Entity
public class Category {
  private Long id;
  private String name;

  // getters, setters, equals, hashcode
}

editStore.xhtml

<h:form>
....
  <h:selectOneMenu value="#{backingBean.store.category}" id="category">
    <f:selectItems value="#{backingBean.categorySelectItems}" />
  </h:selectOneMenu>
....
</h:form>

BackingBean.java

public class BackingBean {
  private Store store;

  // inject data-access-facades via @EJB
  // Constructor
  // getters, setters

  public List<SelectItem> getCategorySelectItems
    List<SelectItem> items = new ArrayList<SelectItem>();
    for (Category cat : categoryFacade.findAll() ) {
      items.add(new SelectItem(cat, cat.getName()));
    }
    return items;
  }

  // action methods
}

I leave out listing the Category-Converter (it c开发者_开发百科onverts between the object and its ID).

The HTML this creates is:

<select id="category" name="category" size="1">
  <option value="251" selected="selected">Kosmetik</option>
  <option value="222" selected="selected">Sportwaren</option>
</select>

Obviously, store.category can only contain one item... why are both option-elements "selected"? No matter, what category is assigned to the store, the HTML always "selects" all option-elements.

How does JSF now, which SelectItem should be selected?


It's almost certain that the problem is in the equals(..) method, which returns true for all compared objects. Test this, and let your IDE generate the method (together with hashCode())

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