PlayFramework bindFromRequest（）以扩展通用模型的模型形式出现

Question

我第一次在扩展泛型对象的模型中使用“从类播放”对象。

当我试图从请求绑定并将其分配到我的具体模型的表单时，出现了错误：

Form<Unit> filled_form = form(Unit.class).bindFromRequest();

我得到的错误：

[error] play - Cannot invoke the action, eventually got an error: javax.validation.ValidationException: HV000041: Call to TraversableResolver.isReachable() threw an exception.

堆栈跟踪：

FORM TEST
[error] play - Cannot invoke the action, eventually got an error: javax.validation.ValidationException: HV000041: Call to TraversableResolver.isReachable() threw an exception.
[error] application - 

! @6kb173m85 - Internal server error, for (POST) [/SupraADMIN/oddzialy/zapisz] ->

play.api.Application$$anon$1: Execution exception[[ValidationException: HV000041: Call to TraversableResolver.isReachable() threw an exception.]]
        at play.api.Application$class.handleError(Application.scala:293) ~[play_2.10.jar:2.2.4]
        at play.api.DefaultApplication.handleError(Application.scala:399) [play_2.10.jar:2.2.4]
        at play.core.server.netty.PlayDefaultUpstreamHandler$$anonfun$3$$anonfun$applyOrElse$3.apply(PlayDefaultUpstreamHandler.scala:264) [play_2.10.jar:2.2.4]
        at play.core.server.netty.PlayDefaultUpstreamHandler$$anonfun$3$$anonfun$applyOrElse$3.apply(PlayDefaultUpstreamHandler.scala:264) [play_2.10.jar:2.2.4]
        at scala.Option.map(Option.scala:145) [scala-library.jar:na]
        at play.core.server.netty.PlayDefaultUpstreamHandler$$anonfun$3.applyOrElse(PlayDefaultUpstreamHandler.scala:264) [play_2.10.jar:2.2.4]
Caused by: javax.validation.ValidationException: HV000041: Call to TraversableResolver.isReachable() threw an exception.
        at org.hibernate.validator.internal.engine.ValidatorImpl.isReachable(ValidatorImpl.java:1316) ~[hibernate-validator.jar:5.0.1.Final]
        at org.hibernate.validator.internal.engine.ValidatorImpl.isValidationRequired(ValidatorImpl.java:1292) ~[hibernate-validator.jar:5.0.1.Final]
        at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraint(ValidatorImpl.java:475) ~[hibernate-validator.jar:5.0.1.Final]
        at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForDefaultGroup(ValidatorImpl.java:424) ~[hibernate-validator.jar:5.0.1.Final]
        at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForCurrentGroup(ValidatorImpl.java:388) ~[hibernate-validator.jar:5.0.1.Final]
        at org.hibernate.validator.internal.engine.ValidatorImpl.validateInContext(ValidatorImpl.java:340) ~[hibernate-validator.jar:5.0.1.Final]
Caused by: java.lang.NullPointerException: null
        at models.Generic.hashCode(Generic.java:128) ~[na:na]
        at org.hibernate.validator.internal.engine.resolver.SingleThreadCachedTraversableResolver$TraversableHolder.buildHashCode(SingleThreadCachedTraversableResolver.java:153) ~[hibernate-validator.jar:5.0.1.Final]
        at org.hibernate.validator.internal.engine.resolver.SingleThreadCachedTraversableResolver$TraversableHolder.<init>(SingleThreadCachedTraversableResolver.java:114) ~[hibernate-validator.jar:5.0.1.Final]
        at org.hibernate.validator.internal.engine.resolver.SingleThreadCachedTraversableResolver$TraversableHolder.<init>(SingleThreadCachedTraversableResolver.java:96) ~[hibernate-validator.jar:5.0.1.Final]
        at org.hibernate.validator.internal.engine.resolver.SingleThreadCachedTraversableResolver.isReachable(SingleThreadCachedTraversableResolver.java:41) ~[hibernate-validator.jar:5.0.1.Final]
        at org.hibernate.validator.internal.engine.ValidatorImpl.isReachable(ValidatorImpl.java:1307) ~[hibernate-validator.jar:5.0.1.Final]
[error] application - REGUEST: POST /SupraADMIN/oddzialy/zapisz GENERATED ERROR: @6kb173m85: Execution exception in /home/korbeldaniel/Aplikacje/Eclipse/SVP/modules/admin/app/controllers/CMS.java:472

以下是我的控制器方法：

        System.out.println("FORM TEST");
        Form<Unit> filled_form = form(Unit.class).bindFromRequest();
        System.out.println(filled_form);
        if (filled_form.hasErrors()) {
            List<Unit> unitsList = new Unit().getList();
            return badRequest(views.html.CMS.UnitsAdd.render(unitsList,filled_form,new Unit().prepareJsonTree()));
        } else {
            filled_form.get().toDataBase();
            flash("success", "Pomyślnie dodano.");
            return redirect(routes.CMS.Units());
        }

和模型类：

@Entity
@Table(name="common__Unit")
public class Unit extends GenericDictionary<Unit> {
    @ManyToOne(fetch=FetchType.LAZY)
    @JoinColumn(name="parent_id")
    public Unit parent;

以及通过单元模型扩展的GenericDictionary模型：

@MappedSuperclass
public abstract class GenericDictionary<T extends Generic<T>> extends Generic<T> {

    @Required
    public String name;
    @Required
    public boolean active = true;

以及由GenericDictionary模型扩展的通用模型：

@MappedSuperclass
public abstract class Generic<T extends Generic> {
    @Transient
    public Class<T> entityClass;
    Generic() {
        entityClass = ((Class) ((Class) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[0]));
    }
    @Id
    @GeneratedValue(strategy = GenerationType.TABLE)
    public Long id;

    @ManyToOne(cascade = CascadeType.MERGE)
    @Constraints.Required
    public User creationUser;

请帮帮我。

Answer 1

当使用复杂类型层次结构时，getGenericSuperclass方法不起作用。相反，您可以尝试使用TypeTools：

Generic() {
    entityClass = (Class<T>)TypeResolver.resolveRawArgument(Generic.class, getClass());
}