CODEWITHSUNDEEP
javavaadinvaadin7
Skizzo
Skizzo

Reputation: 2983

Can't bind a nested property along a BeanFieldGroup

I'm developing a vaadin application and now have the following trouble. I'm trying to bind a nested property along BeanFieldGroup.

MyEntity Class

@Entity
public class MyEntity implements Serializable {
private static final long serialVersionUID = 1L;

@EmbeddedId
private MyEntityPK id;

//Others Property

public MyEntityPK getId() {
    return this.id;
}

public void setId(MyEntityPK id) {
    this.id = id;
}


}

MyEntityPK Class

@Embeddable
public class MyEntityPK implements Serializable {


@Column(name="CD_VARIABILE")
private String cdVariabile;

public String getCdVariabile() {
    return this.cdVariabile;
}
public void setCdVariabile(String cdVariabile) {
    this.cdVariabile = cdVariabile;
}

}

MyVaadinPanel

private BeanFieldGroup<MyEntity> binder;
binder = new BeanFieldGroup<MyEntity>(MyEntity.class);
binder.setItemDataSource(new BeanItem<MyEntity>(new MyEntity()));
variabileBinder.bind(new TextField(), "id.cdVariabile");

When, I try to bind the property "id.cdVariabile" to TextFiel, I get the following error:

Caused by: com.vaadin.data.util.MethodProperty$MethodException
at com.vaadin.data.util.NestedMethodProperty.getValue(NestedMethodProperty.java:205)
at com.vaadin.data.util.TransactionalPropertyWrapper.getValue(TransactionalPropertyWrapper.java:73)
at com.vaadin.ui.AbstractField.getDataSourceValue(AbstractField.java:299)
at com.vaadin.ui.AbstractField.setPropertyDataSource(AbstractField.java:629)
... 48 more
   Caused by: java.lang.NullPointerException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.vaadin.data.util.NestedMethodProperty.getValue(NestedMethodProperty.java:201)
... 51 more

Where am I wrong ?

Upvotes: 1

Views: 1990

Answers (1)

Morfic
Morfic

Reputation: 15518

Looks like when you create your entity in binder.setItemDataSource(new BeanItem<MyEntity>(new MyEntity())); its id is null, hence trying to rerieve id.cdVariabile would result in NPE. Try adding a PK:

    BeanFieldGroup<MyEntity> binder;
    binder = new BeanFieldGroup<MyEntity>(MyEntity.class);
    MyEntity myEntity = new MyEntity();
    myEntity.setId(new MyEntityPK());
    binder.setItemDataSource(new BeanItem<MyEntity>(myEntity));
    binder.bind(new TextField(), "id.cdVariabile");

Upvotes: 2

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