Question

我正在使用Netbeans开发JPA的JSF应用程序。我创建Entity类，然后通过Netbeans从Entity类生成JSF页面。它创建了一个AbstractFacade，Facade扩展了每个实体的抽象外观，每个实体的控制器bean和一个JSF页面。然后我改变并使用这些生成的代码来创建我的逻辑。

当我在单个JSF页面中使用两个控制器bean时，间歇性地 ClassCastException 。但是当我重新启动GLassFish服务器时，异常会消失一段时间并再次出现，我无法找到启动更改的内容。例如，考虑一个名为Atm的实体的情况。它有一个属性MedicineGroup，它也是另一个实体。当一个来自Atm实体的对象将通过JSF页面保存时，我得到所有的MedicineGroups调用MedicineGroupController并将其分配给Atm对象的选定GenericName属性。这种逻辑很有效，直到发生ClassCastException。

（大多数JSF页面使用相同的上述方法.ATM实体具有Vtm属性.Ampp具有Atm atm，MeasurmentUnit strengthUnit，Double strength，Double rol等特性。）

我也可以通过更改逻辑来完成同样的事情，这样每个JSF页面只有一个控制器，但是如果可以在同一个JSF页面中引用多个控制器bean，那就很容易了。

这里有什么问题？

我在下面列出了一些重要的代码。

JSF页面的相关部分。

<h:selectOneListbox id="txtGroup" value="#{vtmController.current.medicineGroup}" size="5" >
    <f:selectItems value="#{medicineGroupController.items}" var="gp" itemValue="#{gp}" itemLabel="#{gp.name}"/>
</h:selectOneListbox>

实体类的示例

@Entity
@Inheritance
public class Vtm extends PharmaceuticalItem implements Serializable {

@ManyToOne
MedicineGroup medicineGroup;

public MedicineGroup getMedicineGroup() {
    return medicineGroup;
}

public void setMedicineGroup(MedicineGroup medicineGroup) {
    this.medicineGroup = medicineGroup;
}



}

包含自动生成转换器的控制器类示例。

@ManagedBean
@SessionScoped
public final class VtmController {

@EJB
private VtmFacade ejbFacade;
SessionController sessionController = new SessionController();
List<Vtm> lstItems;
private Vtm current;
private DataModel<Vtm> items = null;
private int selectedItemIndex;
boolean selectControlDisable = false;
boolean modifyControlDisable = true;
String selectText = "";

public VtmController() {
}

public List<Vtm> getLstItems() {
    return getFacade().findBySQL("Select d From Vtm d");
}

public void setLstItems(List<Vtm> lstItems) {
    this.lstItems = lstItems;
}

public int getSelectedItemIndex() {
    return selectedItemIndex;
}

public void setSelectedItemIndex(int selectedItemIndex) {
    this.selectedItemIndex = selectedItemIndex;
}

public Vtm getCurrent() {
    if (current == null) {
        current = new Vtm();
    }
    return current;
}

public void setCurrent(Vtm current) {
    this.current = current;
}

private VtmFacade getFacade() {
    return ejbFacade;
}

public DataModel<Vtm> getItems() {
    items = new ListDataModel(getFacade().findAll("name", true));
    return items;
}

public static int intValue(long value) {
    int valueInt = (int) value;
    if (valueInt != value) {
        throw new IllegalArgumentException(
                "The long value " + value + " is not within range of the int type");
    }
    return valueInt;
}

public DataModel searchItems() {
    recreateModel();
    if (items == null) {
        if (selectText.equals("")) {
            items = new ListDataModel(getFacade().findAll("name", true));
        } else {
            items = new ListDataModel(getFacade().findAll("name", "%" + selectText + "%",
                    true));
            if (items.getRowCount() > 0) {
                items.setRowIndex(0);
                current = (Vtm) items.getRowData();
                Long temLong = current.getId();
                selectedItemIndex = intValue(temLong);
            } else {
                current = null;
                selectedItemIndex = -1;
            }
        }
    }
    return items;

}

public Vtm searchItem(String itemName, boolean createNewIfNotPresent) {
    Vtm searchedItem = null;
    items = new ListDataModel(getFacade().findAll("name", itemName, true));
    if (items.getRowCount() > 0) {
        items.setRowIndex(0);
        searchedItem = (Vtm) items.getRowData();
    } else if (createNewIfNotPresent) {
        searchedItem = new Vtm();
        searchedItem.setName(itemName);
        searchedItem.setCreatedAt(Calendar.getInstance().getTime());
        searchedItem.setCreater(sessionController.loggedUser);
        getFacade().create(searchedItem);
    }
    return searchedItem;
}

private void recreateModel() {
    items = null;
}

public void prepareSelect() {
    this.prepareModifyControlDisable();
}

public void prepareEdit() {
    if (current != null) {
        selectedItemIndex = intValue(current.getId());
        this.prepareSelectControlDisable();
    } else {
        JsfUtil.addErrorMessage(new MessageProvider().getValue("nothingToEdit"));
    }
}

public void prepareAdd() {
    selectedItemIndex = -1;
    current = new Vtm();
    this.prepareSelectControlDisable();
}

public void saveSelected() {
    if (selectedItemIndex > 0) {
        getFacade().edit(current);
        JsfUtil.addSuccessMessage(new MessageProvider().getValue("savedOldSuccessfully"));
    } else {
        current.setCreatedAt(Calendar.getInstance().getTime());
        current.setCreater(sessionController.loggedUser);
        getFacade().create(current);
        JsfUtil.addSuccessMessage(new MessageProvider().getValue("savedNewSuccessfully"));
    }
    this.prepareSelect();
    recreateModel();
    getItems();
    selectText = "";
    selectedItemIndex = intValue(current.getId());
}

public void addDirectly() {
    JsfUtil.addSuccessMessage("1");
    try {

        current.setCreatedAt(Calendar.getInstance().getTime());
        current.setCreater(sessionController.loggedUser);

        getFacade().create(current);
        JsfUtil.addSuccessMessage(new MessageProvider().getValue("savedNewSuccessfully"));
        current = new Vtm();
    } catch (Exception e) {
        JsfUtil.addErrorMessage(e, "Error");
    }

}

public void cancelSelect() {
    this.prepareSelect();
}

public void delete() {
    if (current != null) {
        current.setRetired(true);
        current.setRetiredAt(Calendar.getInstance().getTime());
        current.setRetirer(sessionController.loggedUser);
        getFacade().edit(current);
        JsfUtil.addSuccessMessage(new MessageProvider().getValue("deleteSuccessful"));
    } else {
        JsfUtil.addErrorMessage(new MessageProvider().getValue("nothingToDelete"));
    }
    recreateModel();
    getItems();
    selectText = "";
    selectedItemIndex = -1;
    current = null;
    this.prepareSelect();
}

public boolean isModifyControlDisable() {
    return modifyControlDisable;
}

public void setModifyControlDisable(boolean modifyControlDisable) {
    this.modifyControlDisable = modifyControlDisable;
}

public boolean isSelectControlDisable() {
    return selectControlDisable;
}

public void setSelectControlDisable(boolean selectControlDisable) {
    this.selectControlDisable = selectControlDisable;
}

public String getSelectText() {
    return selectText;
}

public void setSelectText(String selectText) {
    this.selectText = selectText;
    searchItems();
}

public void prepareSelectControlDisable() {
    selectControlDisable = true;
    modifyControlDisable = false;
}

public void prepareModifyControlDisable() {
    selectControlDisable = false;
    modifyControlDisable = true;
}

@FacesConverter(forClass = Vtm.class)
public static class VtmControllerConverter implements Converter {

    public Object getAsObject(FacesContext facesContext, UIComponent component, String value) {
        if (value == null || value.length() == 0) {
            return null;
        }
        VtmController controller = (VtmController) facesContext.getApplication().getELResolver().
                getValue(facesContext.getELContext(), null, "vtmController");
        return controller.ejbFacade.find(getKey(value));
    }

    java.lang.Long getKey(String value) {
        java.lang.Long key;
        key = Long.valueOf(value);
        return key;
    }

    String getStringKey(java.lang.Long value) {
        StringBuffer sb = new StringBuffer();
        sb.append(value);
        return sb.toString();
    }

    public String getAsString(FacesContext facesContext, UIComponent component, Object object) {
        if (object == null) {
            return null;
        }
        if (object instanceof Vtm) {
            Vtm o = (Vtm) object;
            return getStringKey(o.getId());
        } else {
            throw new IllegalArgumentException("object " + object + " is of type "
                    + object.getClass().getName() + "; expected type: " + VtmController.class.getName());
        }
    }
}
}

门面的示例

@Stateless
public class VtmFacade extends AbstractFacade<Vtm> {
@PersistenceContext(unitName = "HOPU")
private EntityManager em;

@Override
protected EntityManager getEntityManager() {
    return em;
}

public VtmFacade() {
    super(Vtm.class);
}


}

生成的抽象外观和我所做的更改。

public abstract class AbstractFacade<T> {

protected Class<T> entityClass;

public AbstractFacade(Class<T> entityClass) {
    this.entityClass = entityClass;
}

protected abstract EntityManager getEntityManager();

public void create(T entity) {
    getEntityManager().persist(entity);
}

public void edit(T entity) {
    getEntityManager().merge(entity);
}

public void remove(T entity) {
    getEntityManager().remove(getEntityManager().merge(entity));
}

public T find(Object id) {
    return getEntityManager().find(entityClass, id);
}

public List<T> findAll(boolean withoutRetired) {
    return findAll(null, null, withoutRetired);
}

public List<T> findAll() {
    javax.persistence.criteria.CriteriaBuilder cb = getEntityManager().getCriteriaBuilder();
    javax.persistence.criteria.CriteriaQuery<T> cq = cb.createQuery(entityClass);
    javax.persistence.criteria.Root<T> rt = cq.from(entityClass);
    return getEntityManager().createQuery(cq).getResultList();
}

public List<T> findAll(String fieldName) {
    return findAll(fieldName, "", false);
}

public List<T> findAll(String fieldName, boolean withoutRetired) {
    return findAll(fieldName, "", withoutRetired);
}

public List<T> findAll(String fieldName, String fieldValue) {
    return findAll(fieldName, fieldValue, false);
}

public List<T> findBySQL(String temSQL) {
    TypedQuery<T> qry = getEntityManager().createQuery(temSQL, entityClass);
    return qry.getResultList();
}


public List<T> findBySQL(String temSQL, Map<String, Date> parameters) {
    TypedQuery<T> qry = getEntityManager().createQuery(temSQL, entityClass);
    Set s=parameters.entrySet();
    Iterator it=s.iterator();
    while (it.hasNext()){
        Map.Entry m=(Map.Entry)it.next();
        Date pVal =  (Date) m.getValue();
        String pPara=(String) m.getKey();
        qry.setParameter(pPara, pVal, TemporalType.DATE);
        System.out.println("Parameter " + pPara + "\tVal" + pVal);
    }
    return qry.getResultList();
}    

private void test(Class myClass, Object ob) {
}

public List<T> findAll(String fieldName, String fieldValue, boolean withoutRetired) {
    javax.persistence.criteria.CriteriaBuilder cb = getEntityManager().getCriteriaBuilder();
    javax.persistence.criteria.CriteriaQuery<T> cq = cb.createQuery(entityClass);
    javax.persistence.criteria.Root<T> rt = cq.from(entityClass);
    ParameterExpression<String> p = cb.parameter(String.class);
    Predicate predicateField = cb.like(rt.<String>get(fieldName), fieldValue);
    Predicate predicateRetired = cb.equal(rt.<Boolean>get("retired"), false);
    Predicate predicateFieldRetired = cb.and(predicateField, predicateRetired);

    if (withoutRetired && !fieldValue.equals("")) {
        cq.where(predicateFieldRetired);
    } else if (withoutRetired) {
        cq.where(predicateRetired);
    } else if (!fieldValue.equals("")) {
        cq.where(predicateField);
    }

    if (!fieldName.equals("")) {
        cq.orderBy(cb.asc(rt.get(fieldName)));
    }

    return getEntityManager().createQuery(cq).getResultList();
}

public List<T> findExact(String fieldName, String fieldValue, boolean withoutRetired) {
    javax.persistence.criteria.CriteriaBuilder cb = getEntityManager().getCriteriaBuilder();
    javax.persistence.criteria.CriteriaQuery<T> cq = cb.createQuery(entityClass);
    javax.persistence.criteria.Root<T> rt = cq.from(entityClass);
    ParameterExpression<String> p = cb.parameter(String.class);
    Predicate predicateField = cb.equal(cb.upper(rt.<String>get(fieldName)), fieldValue.toLowerCase());
    Predicate predicateRetired = cb.equal(rt.<Boolean>get("retired"), false);
    Predicate predicateFieldRetired = cb.and(predicateField, predicateRetired);

    if (withoutRetired && !fieldValue.equals("")) {
        cq.where(predicateFieldRetired);
    } else if (withoutRetired) {
        cq.where(predicateRetired);
    } else if (!fieldValue.equals("")) {
        cq.where(predicateField);
    }

    if (!fieldName.equals("")) {
        cq.orderBy(cb.asc(rt.get(fieldName)));
    }

    return getEntityManager().createQuery(cq).getResultList();
}

public T findByField(String fieldName, String fieldValue, boolean withoutRetired) {
    List<T> lstAll = findExact(fieldName, fieldValue, true);
    if (lstAll.isEmpty()) {
        return null;
    } else {
        return lstAll.get(0);
    }
}

public T findFirstBySQL(String temSQL) {
    TypedQuery<T> qry = getEntityManager().createQuery(temSQL, entityClass);
    try {
        return qry.getResultList().get(0);
    } catch (Exception e) {
        System.out.println(e.getMessage());
        return null;
    }
}

public <U> List<T> testMethod(U[] a, Collection<U> all) {
    List<T> myList = new ArrayList<T>();
    return myList;
}

public <U> List<T> findAll(String fieldName, int searchID, boolean withoutRetired) {

    javax.persistence.criteria.CriteriaBuilder cb = getEntityManager().getCriteriaBuilder();
    javax.persistence.criteria.CriteriaQuery<T> cq = cb.createQuery(entityClass);
    javax.persistence.criteria.Root<T> rt = cq.from(entityClass);

    if (withoutRetired) {
        cq.where(cb.and(cb.equal(rt.get("retired"), false)),
                (cb.equal(rt.get(fieldName).get("id"), searchID)));
    } else {
        cq.where(cb.equal(rt.get("retired"), false));
    }

    return getEntityManager().createQuery(cq).getResultList();
}

public int count() {
    javax.persistence.criteria.CriteriaQuery cq = getEntityManager().getCriteriaBuilder().createQuery();
    javax.persistence.criteria.Root<T> rt = cq.from(entityClass);
    cq.select(getEntityManager().getCriteriaBuilder().count(rt));
    javax.persistence.Query q = getEntityManager().createQuery(cq);
    return ((Long) q.getSingleResult()).intValue();
}


public Double findAggregateDbl(String strJQL){
    Query q= getEntityManager().createQuery(strJQL);
    try{
        return (Double) q.getSingleResult();
    }catch (Exception e){
        System.out.println(e.getMessage());
        return 0.0;
    }
}


}

这是异常引用的代码。

            AtmController controller = (AtmController) facesContext.getApplication().getELResolver().
                getValue(facesContext.getELContext(), null, "atmController");

在不同的实例中，这个相应的位置相同，但控制器不同。当错误发生一次，尽管后面的JSF页面访问，同一个控制器给出错误，但在服务器重启后，控制器根据发生错误的页面而有所不同。

这是完整的堆栈跟踪。（控制器类的名称根据我用来访问的JSF页面而改变。）

INFO: java.lang.ClassCastException: gov.sp.health.bean.VtmController cannot be cast to gov.sp.health.bean.AtmController
java.lang.ClassCastException: gov.sp.health.bean.VtmController cannot be cast to gov.sp.health.bean.AtmController
    at gov.sp.health.bean.AtmController$VtmControllerConverter.getAsObject(AtmController.java:252)
    at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getConvertedValue(HtmlBasicInputRenderer.java:171)
    at com.sun.faces.renderkit.html_basic.MenuRenderer.convertSelectOneValue(MenuRenderer.java:202)
    at com.sun.faces.renderkit.html_basic.MenuRenderer.getConvertedValue(MenuRenderer.java:319)
    at javax.faces.component.UIInput.getConvertedValue(UIInput.java:1030)
    at javax.faces.component.UIInput.validate(UIInput.java:960)
    at javax.faces.component.UIInput.executeValidate(UIInput.java:1233)
    at javax.faces.component.UIInput.processValidators(UIInput.java:698)
    at com.sun.faces.context.PartialViewContextImpl$PhaseAwareVisitCallback.visit(PartialViewContextImpl.java:508)
    at com.sun.faces.component.visit.PartialVisitContext.invokeVisitCallback(PartialVisitContext.java:183)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1590)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
    at javax.faces.component.UIForm.visitTree(UIForm.java:344)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
    at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
    at com.sun.faces.context.PartialViewContextImpl.processComponents(PartialViewContextImpl.java:376)
    at com.sun.faces.context.PartialViewContextImpl.processPartial(PartialViewContextImpl.java:252)
    at javax.faces.context.PartialViewContextWrapper.processPartial(PartialViewContextWrapper.java:183)
    at javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:1170)
    at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:76)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1542)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:343)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:217)
    at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:79)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:217)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195)
    at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:849)
    at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:746)
    at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1045)
    at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:228)
    at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
    at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
    at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
    at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
    at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
    at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
    at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
    at java.lang.Thread.run(Thread.java:722)

AtmController内的转换器

@FacesConverter(forClass = Atm.class)
public static class AtmControllerConverter implements Converter {

    public Object getAsObject(FacesContext facesContext, UIComponent component, String value) {
        if (value == null || value.length() == 0) {
            return null;
        }
        AtmController controller = (AtmController) facesContext.getApplication().getELResolver().
                getValue(facesContext.getELContext(), null, "atmController");
        return controller.ejbFacade.find(getKey(value));
    }

    java.lang.Long getKey(String value) {
        java.lang.Long key;
        key = Long.valueOf(value);
        return key;
    }

    String getStringKey(java.lang.Long value) {
        StringBuffer sb = new StringBuffer();
        sb.append(value);
        return sb.toString();
    }

    public String getAsString(FacesContext facesContext, UIComponent component, Object object) {
        if (object == null) {
            return null;
        }
        if (object instanceof Atm) {
            Atm o = (Atm) object;
            return getStringKey(o.getId());
        } else {
            throw new IllegalArgumentException("object " + object + " is of type "
                    + object.getClass().getName() + "; expected type: " + AtmController.class.getName());
        }
    }
}

VtmController内的转换器

@FacesConverter(forClass = Vtm.class)
public static class VtmControllerConverter implements Converter {

    public Object getAsObject(FacesContext facesContext, UIComponent component, String value) {
        if (value == null || value.length() == 0) {
            return null;
        }
        VtmController controller = (VtmController) facesContext.getApplication().getELResolver().
                getValue(facesContext.getELContext(), null, "vtmController");
        return controller.ejbFacade.find(getKey(value));
    }

    java.lang.Long getKey(String value) {
        java.lang.Long key;
        key = Long.valueOf(value);
        return key;
    }

    String getStringKey(java.lang.Long value) {
        StringBuffer sb = new StringBuffer();
        sb.append(value);
        return sb.toString();
    }

    public String getAsString(FacesContext facesContext, UIComponent component, Object object) {
        if (object == null) {
            return null;
        }
        if (object instanceof Vtm) {
            Vtm o = (Vtm) object;
            return getStringKey(o.getId());
        } else {
            throw new IllegalArgumentException("object " + object + " is of type "
                    + object.getClass().getName() + "; expected type: " + VtmController.class.getName());
        }
    }
}

在MedicineGroupController中的转换器

@FacesConverter(forClass = MedicineGroup.class)
public static class MedicineGroupControllerConverter implements Converter {

    public Object getAsObject(FacesContext facesContext, UIComponent component, String value) {
        if (value == null || value.length() == 0) {
            return null;
        }
        MedicineGroupController controller = (MedicineGroupController) facesContext.getApplication().getELResolver().
                getValue(facesContext.getELContext(), null, "medicineGroupController");
        return controller.ejbFacade.find(getKey(value));
    }

    java.lang.Long getKey(String value) {
        java.lang.Long key;
        key = Long.valueOf(value);
        return key;
    }

    String getStringKey(java.lang.Long value) {
        StringBuffer sb = new StringBuffer();
        sb.append(value);
        return sb.toString();
    }

    public String getAsString(FacesContext facesContext, UIComponent component, Object object) {
        if (object == null) {
            return null;
        }
        if (object instanceof MedicineGroup) {
            MedicineGroup o = (MedicineGroup) object;
            return getStringKey(o.getId());
        } else {
            throw new IllegalArgumentException("object " + object + " is of type "
                    + object.getClass().getName() + "; expected type: " + MedicineGroupController.class.getName());
        }
    }
}

Answer 1

我为每个selectOneListbox使用了转换器。字后没有出现错误。以下是我使用的类似示例。（与上面的代码不完全相同）

初始转换器

@FacesConverter(forClass = Investigation.class)
public static class InvestigationControllerConverter implements Converter {

    public InvestigationControllerConverter() {
    }

    @Override
    public Object getAsObject(FacesContext facesContext, UIComponent component, String value) {
        if (value == null || value.length() == 0) {
            return null;
        }
        InvestigationController controller = (InvestigationController) facesContext.getApplication().getELResolver().
                getValue(facesContext.getELContext(), null, "investigationController");
        return controller.ejbFacade.find(getKey(value));
    }

    java.lang.Long getKey(String value) {
        java.lang.Long key;
        key = Long.valueOf(value);
        return key;
    }

    String getStringKey(java.lang.Long value) {
        StringBuilder sb = new StringBuilder();
        sb.append(value);
        return sb.toString();
    }

    @Override
    public String getAsString(FacesContext facesContext, UIComponent component, Object object) {
        if (object == null) {
            return null;
        }
        if (object instanceof Investigation) {
            Investigation o = (Investigation) object;
            return getStringKey(o.getId());
        } else {
            throw new IllegalArgumentException("object " + object + " is of type "
                    + object.getClass().getName() + "; expected type: " + InvestigationController.class.getName());
        }
    }
}

后来我改变了这个。

    @FacesConverter("ixcon")
    public static class InvestigationConverter implements Converter {

        public InvestigationConverter() {
        }



@Override
    public Object getAsObject(FacesContext facesContext, UIComponent component, String value) {
        if (value == null || value.length() == 0) {
            return null;
        }
        InvestigationController controller = (InvestigationController) facesContext.getApplication().getELResolver().
                getValue(facesContext.getELContext(), null, "investigationController");
        return controller.getEjbFacade().find(getKey(value));
    }

    java.lang.Long getKey(String value) {
        java.lang.Long key;
        key = Long.valueOf(value);
        return key;
    }

    String getStringKey(java.lang.Long value) {
        StringBuilder sb = new StringBuilder();
        sb.append(value);
        return sb.toString();
    }

    @Override
    public String getAsString(FacesContext facesContext, UIComponent component, Object object) {
        if (object == null) {
            return null;
        }
        if (object instanceof Investigation) {
            Investigation o = (Investigation) object;
            return getStringKey(o.getId());
        } else {
            throw new IllegalArgumentException("object " + object + " is of type "
                    + object.getClass().getName() + "; expected type: " + InvestigationController.class.getName());
            }
        }
    }

我在JSF页面中使用了这个转换器。

 <p:autoComplete  converter="ixcon" widgetVar="aIx" id="acIx" forceSelection="true" value="#{investigationItemValueFlagController.investigation}" completeMethod="#{investigationController.completeItem}" var="ix" itemLabel="#{ix.name}" itemValue="#{ix}" size="30"  style="width: 400px;">
                                <p:ajax process="acIx iif" update="iif tbl" event="itemSelect"/>
                            </p:autoComplete>

ClassCastException在单个JSF中使用两个控制器时

1 个答案: