【发布时间】：2014-07-17 19:41:50
【问题描述】：
我有两个 primefaces 数据表。第一个显示 MainEntity 的实例。 第二个显示与第一个数据表上选定的 MainEntity 关联的单词列表（只是字符串）。
打印屏幕说明了我的意思。
我的问题是，当我在单词列表上编辑一个字符串时，我的侦听器方法不会接收到新值。事实上，当我调用event.getNewValue() 方法时，我得到的是旧值。
我错过了什么？
我正在使用 JavaServer Faces 2.2、Primefaces 5.0 和 Spring Framework 4.0.3。
提前感谢您的帮助。
xhtml、托管bean和MainEntity的代码如下：
mainEntity.xhtml:
<h:body>
<h:form id="mainEntityForm">
<p:panelGrid columns="1" fullPage="true" id="dashboard">
<f:facet name="header">
<h2>MainEntity Table</h2>
</f:facet>
<p:panel>
<f:facet name="header">
MainEntity List
<p:commandButton value="New MainEntity"
actionListener="#{mainEntityController.createMainEntityDialog}"
styleClass="header-button">
<p:ajax event="dialogReturn" update=":mainEntityForm:mainEntityTable" />
</p:commandButton>
</f:facet>
<p:dataTable id="mainEntityTable" var="mainEntity" value="#{mainEntityController.mainEntities}"
editable="true" editMode="cell" widgetVar="cellMainEntity"
selectionMode="single" selection="#{mainEntityController.selectedMainEntity}"
rowKey="#{mainEntity.id}" tableStyle="width:auto">
<p:ajax event="rowSelect" update=":mainEntityForm:stringGrid :mainEntityForm:entityAGrid :mainEntityForm:entityBGrid" />
<p:ajax event="cellEdit" listener="#{mainEntityController.onEditMainEntity}" update=":mainEntityForm:mainEntityTable" />
<p:column headerText="ID">
<h:outputText value="#{mainEntity.id}" />
</p:column>
<p:column headerText="Name">
<p:cellEditor>
<f:facet name="output">
<h:outputText id="nameOutput" value="#{mainEntity.name}" />
</f:facet>
<f:facet name="input">
<h:inputText id="atyInput" value="#{mainEntity.qty}" />
</f:facet>
</p:cellEditor>
</p:column>
<p:column headerText="Commands">
<p:commandButton title="Remove MainEntity" icon="ui-icon-trash"
actionListener="#{mainEntityController.deleteMainEntity(mainEntity)}"
update=":mainEntityForm:mainEntityTable" />
</p:column>
</p:dataTable>
</p:panel>
<p:panelGrid fullPage="true" id="mainEntityDetail">
<f:facet name="header">
<p:row>
<p:column colspan="4">
<h2>MainEntity Detail</h2>
</p:column>
</p:row>
</f:facet>
<p:row>
<p:column>
<p:panel>
<f:facet name="header">
Word List
<p:commandButton value="New Word"
actionListener="#{mainEntityController.addNewWord()}"
styleClass="header-button"
update=":mainEntityForm:wordGrid">
</p:commandButton>
</f:facet>
<p:dataTable id="wordGrid" var="word"
value="#{mainEntityController.selectedMainEntity.wordList}"
tableStyle="width:auto" editable="true" editMode="cell" widgetVar="cellWord">
<p:ajax event="cellEdit" listener="#{mainEntityController.onEditWord}" />
<p:column headerText="Word">
<p:cellEditor>
<f:facet name="output">
<h:outputText id="wordOutput" value="#{word}" />
</f:facet>
<f:facet name="input">
<h:inputText id="wordInput" value="#{word}" />
</f:facet>
</p:cellEditor>
</p:column>
<p:column headerText="Commands">
<p:commandButton title="Remove Word"
icon="ui-icon-trash"
actionListener="#{mainEntityController.removeWord(word)}"
update=":mainEntityForm:wordGrid" />
</p:column>
</p:dataTable>
</p:panel>
</p:column>
</p:row>
</p:panelGrid>
</p:panelGrid>
</h:form>
</h:body>
MainEntityController.java（托管 bean）：
@ManagedBean
@SessionScoped
public class MainEntityController {
//...
private MainEntity selectedMainEntity;
public List<MainEntity> mainEntities;
//...
public MainEntity getSelectedMainEntity(){
return selectedMainEntity;
}
public void setSelectedMainEntity(MainEntity mainEntity){
this.selectedMainEntity = mainEntity;
}
//...
public void onEditWord(CellEditEvent event) {
Object oldValue = event.getOldValue();
Object newValue = event.getNewValue();
if(newValue != null && !newValue.equals(oldValue)) {
// THE PROBLEM IS HERE
// I NEVER ACTUALLY REACH THIS CODE
// newValue is always equal to oldValue!
FacesContext context = FacesContext.getCurrentInstance();
String word = context.getApplication().evaluateExpressionGet(context, "#{word}", String.class);
System.out.println(newValue);
System.out.println(word);
FacesMessage msg = new FacesMessage(FacesMessage.SEVERITY_INFO, "Word Changed", "Old: " + oldValue + ", New:" + newValue);
FacesContext.getCurrentInstance().addMessage(null, msg);
}
}
}
MainEntity.java：
@Entity
public class MainEntity {
@Id
private String id;
@ElementCollection(fetch=FetchType.EAGER)
@CollectionTable(
name="MainEntity_Word",
joinColumns = @JoinColumn(name = "id", referencedColumnName="id")
)
@Column(name = "word")
private Set<String> wordList;
//...
public void addWord(String word) {
this.wordList.add(word);
}
public void removeWord(String word) {
this.wordList.remove(word);
}
public Set<String> getWordList() {
return wordList;
}
public void setWordList(Set<String> wordList) {
this.wordList = wordList;
}
}
【问题讨论】：
-
尝试
implements Serializable到您的实体类和会话 bean。当您必须通过网络传递和检索对象时，您需要序列化它们。 -
@Tiny 抱歉打错了。它实际上是 JSF。我刚刚更正了问题标题。感谢您的警告。
-
@Sujan 再次感谢您的帮助。我会尝试一下，然后返回结果。
-
@Sujan 没用。不过还是感谢您的帮助。
-
@mateuscpf 你做了什么？
标签： jsf primefaces