Question

我正在使用VAADIN 8并遇到问题。我已经在FormLayout上绑定了所有字段，并希望将这些字段中的值保存到db中。所有字段均填充值。问题的实质是当对象保存到数据库时，DateField值将发送为空

问题是为什么DateFiled具有空值，以及如何解决该问题？

VAADIN v.8.6.2

实体（简体）：

@Entity
@DynamicInsert
@DynamicUpdate
@Table(name = "Orders")
public class Order{

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "OrderID", nullable = false)
    private Long orderID;

    @Column(name = "Description", nullable = false, length = 1000)
    private String description;

    @Column(name = "CreationDate", nullable = false)
    private Date creationDate;

public Long getOrderID() { return orderID; }

public String getDescription() { return description; }

public void setDescription(String description) { this.description = description; }

public Date getCreationDate() { return creationDate; }

public void setCreationDate(Date creationDate) { this.creationDate = creationDate; }

}

OrderService（简体）：

public class OrderService {

    private static OrderDao orderService;

    public OrderService() {
        orderService = new OrderDao();
    }

    public void persist(Order entity) {
        orderService.openCurrentSessionwithTransaction();
        orderService.persist(entity);
        orderService.closeCurrentSessionwithTransaction();
    }
}

绑定（简化）：

Binder<Order> binder = new Binder<>(Order.class);
FormLayout formLayout = new FormLayout();
TextField description = new TextField("Description");
DateField creationDate = new DateField("Creation Date");

private Button save = new Button("Save");
private Button cancel = new Button("Cancel");

HorizontalLayout actions = new HorizontalLayout();
actions.addComponents(save, cancel);

formLayout.addComponents(clientId, description, creationDate, actions);

creationDate.setDateFormat("yyyy-MM-dd HH:mm:ss");

binder.forField(this.clientId)
        .bind(Order::getClientID, Order::setClientID);
binder.forField(this.description)
        .bind(Order::getDescription, Order::setDescription);
binder.forField(this.creationDate)
        .withConverter(new SqlDateToLocalDateConverter())
        .bind(Order::getCreationDate, Order::setCreationDate); //the likely problem

binder.bindInstanceFields(this);

binder.setBean(order);

save.addClickListener(e -> save());
cancel.addClickListener(e -> close());

转换器类别：

import com.vaadin.data.Converter;
import com.vaadin.data.Result;
import com.vaadin.data.ValueContext;

import java.sql.Date;
import java.time.LocalDate;

public class SqlDateToLocalDateConverter implements Converter<LocalDate, Date> {

    @Override
    public Result<java.sql.Date> convertToModel(LocalDate value, ValueContext context) {
        if (value == null) {
            return Result.ok(null);
        }
        return Result.ok( java.sql.Date.valueOf(value) );
    }

    @Override
    public LocalDate convertToPresentation(java.sql.Date value, ValueContext context) {
        if (value == null) {
            return LocalDate.now();
        }
        return value.toLocalDate();
    }
}

调试模式指示creationDate字段为null：

stacktrace：

org.hibernate.PropertyValueException: not-null property references a null or transient value : com.haulmont.testtask.model.Order.creationDate
        at org.hibernate.engine.internal.Nullability.checkNullability(Nullability.java:108)
        at org.hibernate.engine.internal.Nullability.checkNullability(Nullability.java:56)
        at org.hibernate.action.internal.AbstractEntityInsertAction.nullifyTransientReferencesIfNotAlready(AbstractEntityInsertAction.java:115)
        at org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:69)
        at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:645)
        at org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:282)
        at org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:263)
        at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:317)
        at org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:359)
        at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:292)
        at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:200)
        at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:131)
        at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192)
        at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38)
        at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177)
        at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32)
        at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)
        at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:709)
        at org.hibernate.internal.SessionImpl.save(SessionImpl.java:701)
        at org.hibernate.internal.SessionImpl.save(SessionImpl.java:696)
        at com.haulmont.testtask.dao.OrderDao.persist(OrderDao.java:67)
        at com.haulmont.testtask.service.OrderService.persist(OrderService.java:18)
        at com.haulmont.testtask.ui.AddOrderModalView.save(AddOrderModalView.java:187)
        at com.haulmont.testtask.ui.AddOrderModalView.lambda$new$61446b05$1(AddOrderModalView.java:111)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:499)
        at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:273)
        at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:237)
        at com.vaadin.server.AbstractClientConnector.fireEvent(AbstractClientConnector.java:1014)
        at com.vaadin.ui.Button.fireClick(Button.java:384)
        at com.vaadin.ui.Button$1.click(Button.java:57)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:155)
        at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:116)
        at com.vaadin.server.communication.ServerRpcHandler.handleInvocation(ServerRpcHandler.java:445)
        at com.vaadin.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:410)
        at com.vaadin.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:274)
        at com.vaadin.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:90)
        at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:40)
        at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1601)
        at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:445)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
        at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:845)
        at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1689)
        at org.eclipse.jetty.websocket.server.WebSocketUpgradeFilter.doFilter(WebSocketUpgradeFilter.java:225)
        at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1676)
        at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:581)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
        at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
        at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:226)
        at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1174)
        at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:511)
        at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
        at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1106)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
        at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:213)
        at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:119)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:134)
        at org.eclipse.jetty.server.Server.handle(Server.java:524)
        at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:319)
        at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:253)
        at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:273)
        at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:95)
        at org.eclipse.jetty.io.SelectChannelEndPoint$2.run(SelectChannelEndPoint.java:93)
        at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.executeProduceConsume(ExecuteProduceConsume.java:303)
        at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.produceConsume(ExecuteProduceConsume.java:148)
        at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.run(ExecuteProduceConsume.java:136)
        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:671)
        at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:589)
        at java.lang.Thread.run(Thread.java:748)

Answer 1

一切正常，除了自定义Converter类中的一个小细节：Date类的使用存在一种不一致。

三次使用java.sql.Date作为该类的标识符，但是一次却忘记使用它（implements Converter<LocalDate, Date>），在那里错误地使用了java.utils.Date。

也可以在其中添加包路径java.sql.Date

import com.vaadin.data.Converter;
import com.vaadin.data.Result;
import com.vaadin.data.ValueContext;

import java.sql.Date;
import java.time.LocalDate;

public class SqlDateToLocalDateConverter implements Converter<LocalDate, java.sql.Date> {

    @Override
    public Result<java.sql.Date> convertToModel(LocalDate value, ValueContext context) {
        if (value == null) {
            return Result.ok(null);
        }
        return Result.ok( java.sql.Date.valueOf(value) );
    }

    @Override
    public LocalDate convertToPresentation(java.sql.Date value, ValueContext context) {
        if (value == null) {
            return LocalDate.now();
        }
        return value.toLocalDate();
    }
}

Vaadin DateField将空值保存到数据库

1 个答案: