Vaadin：DateField 的值在转换后为空
Vaadin: value from DateField is null after conversion
我遇到了无法将 DateField 中输入的日期保存到数据库的问题。我正在使用 Hibernate 作为 ORM 框架，并且有一个包含 java.sql.Date 字段的 Order 实体。但据我所知，DateField 仅适用于 LocalDate/LocalDateTime。因此，为了绑定这些字段，我创建了 Converter class。问题是 Converter 收到了一个空值，这就是我得到堆栈跟踪的原因，但是这个问题在这个线程中得到了解决：
非常感谢@Cashbee。
修复转换器 class 后，值已正确保存到数据库中。但过了一段时间，情况又重复了
目前，当我点击 save() 按钮时，转换器会收到正确的值：
然而，绑定后该值为空：
你能帮我找到解决办法吗
VAADIN v.8.6.2
实体（简化）：
/*imports...*/
import java.sql.Date;
@Entity
@DynamicInsert
@DynamicUpdate
@Table(name = "Orders")
public class Order{
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "OrderID", nullable = false)
private Long orderID;
@Column(name = "CreationDate", nullable = false)
private Date creationDate;
public Date getCreationDate() { return creationDate; }
public void setCreationDate(Date creationDate) { this.creationDate = creationDate; }
//... other getters & setters
}
转换器：
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();
}
}
Class 绑定（简化）：
public class AddOrderModalView extends Window {
private OrderService orderService = new OrderService();
private Order order = new Order();
Binder<Order> binder = new Binder<>(Order.class);
private ChangeHandler changeHandler = new ChangeHandler() {
@Override
public void onChange() { }
};
private FormLayout formLayout = new FormLayout();
private DateField creationDate = new DateField("Creation Date");
private Button save = new Button("Save");
private Button cancel = new Button("Cancel");
public AddOrderModalView() {
VerticalLayout subContent = new VerticalLayout();
subContent.setSizeFull();
HorizontalLayout actions = new HorizontalLayout();
actions.addComponents(save, cancel);
creationDate.setDateFormat("yyyy-MM-dd HH:mm:ss");
formLayout.addComponents(creationDate, actions);
subContent.addComponent(formLayout);
setContent(subContent);
save.addClickListener(e -> save());
cancel.addClickListener(e -> close());
bindingFields();
setModal(true);
}
private void bindingFields() {
binder.forField(this.creationDate)
.withConverter(new SqlDateToLocalDateConverter()) //Converter java.sql.Data -> LocalDate and vise versa
.bind(Order::getCreationDate, Order::setCreationDate);
// ...other fields
//binder.bindInstanceFields(this);
binder.setBean(order);
}
public interface ChangeHandler { void onChange(); }
private void save() {
if (binder.validate().isOk()) {
orderService.persist(order);
close();
changeHandler.onChange();
}
}
}
堆栈跟踪：
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:189)
at com.haulmont.testtask.ui.AddOrderModalView.lambda$new446b05(AddOrderModalView.java:113)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:499)
at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:273)
at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:237)
at com.vaadin.server.AbstractClientConnector.fireEvent(AbstractClientConnector.java:1014)
at com.vaadin.ui.Button.fireClick(Button.java:384)
at com.vaadin.ui.Button.click(Button.java:57)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:155)
at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:116)
at com.vaadin.server.communication.ServerRpcHandler.handleInvocation(ServerRpcHandler.java:445)
at com.vaadin.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:410)
at com.vaadin.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:274)
at com.vaadin.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:90)
at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:40)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1601)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:445)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:845)
at org.eclipse.jetty.servlet.ServletHandler$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.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.run(QueuedThreadPool.java:589)
at java.lang.Thread.run(Thread.java:748)
我重新创建了您的设置，只有细微差别（使用 Vaadin 8.4.3 并且没有尝试保存到数据库）并且对我来说它有效。
不过，我知道你的问题出在哪里：
在您的 Converter 方法 convertToPresentation() 中，您 return LocalDate.now() 如果 java.sql.Date 值为 null。
这将在 DateField 中显示今天的值，尽管 order.creationDate 的值仍然是 null。
仅当您从未通过 DateField 手动更改 creationDate 的值时才会出现该错误。一旦您在那里设置了新值，您的 order.creationDate 值将成功更新并且不再为空。
为防止这种情况发生，请将 convertToPresentation() 的 return 值更改为 null，如果值为 null。
@Override
public LocalDate convertToPresentation(java.sql.Date value, ValueContext context) {
if (value == null) {
//return LocalDate.now();
return null;
}
return value.toLocalDate();
}
如果您希望将 creationDate 值最初设置为今天，您可以在调用 binder.setBean(order);
之前在绑定视图中执行此操作
order.setCreationDate(new java.sql.Date(Calendar.getInstance().getTime().getTime());); //not sure how, I just googled it
binder.setBean(order);
我遇到了无法将 DateField 中输入的日期保存到数据库的问题。我正在使用 Hibernate 作为 ORM 框架，并且有一个包含 java.sql.Date 字段的 Order 实体。但据我所知，DateField 仅适用于 LocalDate/LocalDateTime。因此，为了绑定这些字段，我创建了 Converter class。问题是 Converter 收到了一个空值，这就是我得到堆栈跟踪的原因，但是这个问题在这个线程中得到了解决：
目前，当我点击 save() 按钮时，转换器会收到正确的值：
然而，绑定后该值为空：
你能帮我找到解决办法吗
VAADIN v.8.6.2
实体（简化）：
/*imports...*/
import java.sql.Date;
@Entity
@DynamicInsert
@DynamicUpdate
@Table(name = "Orders")
public class Order{
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "OrderID", nullable = false)
private Long orderID;
@Column(name = "CreationDate", nullable = false)
private Date creationDate;
public Date getCreationDate() { return creationDate; }
public void setCreationDate(Date creationDate) { this.creationDate = creationDate; }
//... other getters & setters
}
转换器：
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();
}
}
Class 绑定（简化）：
public class AddOrderModalView extends Window {
private OrderService orderService = new OrderService();
private Order order = new Order();
Binder<Order> binder = new Binder<>(Order.class);
private ChangeHandler changeHandler = new ChangeHandler() {
@Override
public void onChange() { }
};
private FormLayout formLayout = new FormLayout();
private DateField creationDate = new DateField("Creation Date");
private Button save = new Button("Save");
private Button cancel = new Button("Cancel");
public AddOrderModalView() {
VerticalLayout subContent = new VerticalLayout();
subContent.setSizeFull();
HorizontalLayout actions = new HorizontalLayout();
actions.addComponents(save, cancel);
creationDate.setDateFormat("yyyy-MM-dd HH:mm:ss");
formLayout.addComponents(creationDate, actions);
subContent.addComponent(formLayout);
setContent(subContent);
save.addClickListener(e -> save());
cancel.addClickListener(e -> close());
bindingFields();
setModal(true);
}
private void bindingFields() {
binder.forField(this.creationDate)
.withConverter(new SqlDateToLocalDateConverter()) //Converter java.sql.Data -> LocalDate and vise versa
.bind(Order::getCreationDate, Order::setCreationDate);
// ...other fields
//binder.bindInstanceFields(this);
binder.setBean(order);
}
public interface ChangeHandler { void onChange(); }
private void save() {
if (binder.validate().isOk()) {
orderService.persist(order);
close();
changeHandler.onChange();
}
}
}
堆栈跟踪：
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:189)
at com.haulmont.testtask.ui.AddOrderModalView.lambda$new446b05(AddOrderModalView.java:113)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:499)
at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:273)
at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:237)
at com.vaadin.server.AbstractClientConnector.fireEvent(AbstractClientConnector.java:1014)
at com.vaadin.ui.Button.fireClick(Button.java:384)
at com.vaadin.ui.Button.click(Button.java:57)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:155)
at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:116)
at com.vaadin.server.communication.ServerRpcHandler.handleInvocation(ServerRpcHandler.java:445)
at com.vaadin.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:410)
at com.vaadin.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:274)
at com.vaadin.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:90)
at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:40)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1601)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:445)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:845)
at org.eclipse.jetty.servlet.ServletHandler$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.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.run(QueuedThreadPool.java:589)
at java.lang.Thread.run(Thread.java:748)
我重新创建了您的设置，只有细微差别（使用 Vaadin 8.4.3 并且没有尝试保存到数据库）并且对我来说它有效。
不过，我知道你的问题出在哪里：
在您的 Converter 方法 convertToPresentation() 中，您 return LocalDate.now() 如果 java.sql.Date 值为 null。
这将在 DateField 中显示今天的值，尽管 order.creationDate 的值仍然是 null。
仅当您从未通过 DateField 手动更改 creationDate 的值时才会出现该错误。一旦您在那里设置了新值，您的 order.creationDate 值将成功更新并且不再为空。
为防止这种情况发生，请将 convertToPresentation() 的 return 值更改为 null，如果值为 null。
@Override
public LocalDate convertToPresentation(java.sql.Date value, ValueContext context) {
if (value == null) {
//return LocalDate.now();
return null;
}
return value.toLocalDate();
}
如果您希望将 creationDate 值最初设置为今天，您可以在调用 binder.setBean(order);
order.setCreationDate(new java.sql.Date(Calendar.getInstance().getTime().getTime());); //not sure how, I just googled it
binder.setBean(order);