Question

我正在尝试使用Google Cloud Platform（Eclipse中的插件）在Google Cloud Platform中运行Vaadin项目。运行后，我得到以下异常：

WARNING: Error in serialization of the application: Class 
rand.TestProject.AutoCrudView$1 must implement serialization.
2019-03-02 15:54:06.159:WARN:oejs.session:qtp1757676444-19: 
java.io.NotSerializableException: java.lang.ref.WeakReference
at java.io.ObjectOutputStream.writeObject0(Unknown Source)
at java.io.ObjectOutputStream.writeObject(Unknown Source)
at java.util.LinkedList.writeObject(Unknown Source)
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 java.io.ObjectStreamClass.invokeWriteObject(Unknown Source)
at java.io.ObjectOutputStream.writeSerialData(Unknown Source)
at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source)
at java.io.ObjectOutputStream.writeObject0(Unknown Source)

这是AutoCrudView类：

    @SuppressWarnings("serial")
    public class AutoCrudView  extends Window implements Serializable{
    private static final long serialVersionUID = 1L;

    public AutoCrudView(String PERSISTENCE_UNIT) {
        final HorizontalSplitPanel horizontalSplitPanel = new HorizontalSplitPanel();
        Tree navTree = new Tree();
        navTree.addListener(new Property.ValueChangeListener() {
            /**
             * 
             */
            private static final long serialVersionUID = 1L;

            @Override
            public void valueChange(ValueChangeEvent event) {
                @SuppressWarnings("rawtypes")
                BasicCrudView cv = (BasicCrudView) event.getProperty()
                        .getValue();
                cv.refreshContainer();
                horizontalSplitPanel.setSecondComponent(cv);
            }
        });
        navTree.setSelectable(true);
        navTree.setNullSelectionAllowed(false);
        navTree.setImmediate(true);

        horizontalSplitPanel.setSplitPosition(200,
                HorizontalSplitPanel.UNITS_PIXELS);
        horizontalSplitPanel.addComponent(navTree);
        setContent(horizontalSplitPanel);

        // add a basic crud view for all entities known by the JPA
        // implementation, most often this is not desired and developers
        // should just list those entities they want to have editors for
        Metamodel metamodel = JPAContainerFactory
                .createEntityManagerForPersistenceUnit(PERSISTENCE_UNIT)
                .getEntityManagerFactory().getMetamodel();
        Set<EntityType<?>> entities = metamodel.getEntities();
        for (EntityType<?> entityType : entities) {
            Class<?> javaType = entityType.getJavaType();
            @SuppressWarnings({ "rawtypes", "unchecked" })
            BasicCrudView view = new BasicCrudView(javaType,
                    PERSISTENCE_UNIT);
            navTree.addItem(view);
            navTree.setItemCaption(view, view.getCaption());
            navTree.setChildrenAllowed(view, false);
            if(javaType == Person.class) {
                view.setVisibleTableProperties("firstName","lastName", "boss");
                view.setVisibleFormProperties("firstName","lastName", "phoneNumber", "street", "city", "zipCode", "boss");
            }

        }

        // select first entity view
        navTree.setValue(navTree.getItemIds().iterator().next());
    }

    }

如您所见，我已经实现了Serializable，但是没有成功。这是我从App Engine窗口中获得的图片： here

Answer 1

您会收到有关匿名内部类（类名末尾为$ 1）而不是实际类本身的警告。

所以：去寻找您（偶然）创建一个内部类实例并尝试保留该实例的地方。

也许是

new(...) {

将更改侦听器添加到树对象的位置。如果是这样，问题将是，侦听器是否应该是应该实现该接口的不同类。或者，如果您只是通过尝试尝试保留具有此类侦听器的某些东西而在做错事（不是该框架的专家，我发现坚持包括侦听器实例的ui元素可疑）。

Answer 2

您可以尝试在单独的文件中声明Property.ValueChangeListener并进行检查。

应用程序的序列化错误java.io.NotSerializableException：

2 个答案: