我有两个primefaces dataTables。第一个显示MainEntity的实例。 第二个显示与第一个数据表上所选MainEntity关联的单词列表（只是字符串）。
版画屏幕说明了我的意思。
我的问题是，当我在Word列表中编辑字符串时，我的侦听器方法将不会收到新值。事实上，当我调用event.getNewValue()方法时，我会得到旧值。
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;
}
}
答案 0 :(得分：0)
更改
<h:inputText id="wordInput" value="#{word}" />
到
<p:inputText id="wordInput" value="#{word}" />
或
<h:inputText id="wordInput" value="#{word}" >
<p:ajax event="change" process="@this"/>
</h:inputText>
您需要 ajaxify 输入组件，最后更新outputText组件。
<强>被修改：
更改此栏：
<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>
到
<p:column headerText="Word" >
<p:cellEditor>
<f:facet name="output">
<h:outputText id="wordOutput" value="#{word}" />
</f:facet>
<f:facet name="input">
<p:inputText id="wordInput" value="#{word}" >
<p:ajax event="change" update="wordOutput" />
</p:inputText>
</f:facet>
</p:cellEditor>
</p:column>
编辑2 ：
来自Chapter 24 Introduction to the Java Persistence API
如果实体实例按值传递为分离对象，例如 通过会话bean的远程业务接口，该类必须 实现Serializable接口。
答案 1 :(得分：0)
我终于明白了。
我怀疑字符串是不可变的，我所做的就是封装“＆＃39;字”。在类如下的类中：
public class Word {
private String word;
Word (String word) {
this.setWord(word);
}
public String getWord() {
return this.word;
}
public void setWord(String word) {
this.word = word;
}
}
之后，我还必须在托管bean（控制器）中创建一个集来保存一组单词，比如＆＃39; private Set managedWordList;＆＃39;。
我还更改了托管bean内部列表的getter，将String set转换为Word集：
public Set<Word> getWordList() {
if (this.selectedMainEntity != null){
this.wordList = new HashSet<Word>();
for (String word : this.selectedMainEntity.getWordList()) {
this.wordList.add(new Word(word));
}
}
return this.wordList;
}
最后，我更改了dataTable以引用新集。从：
<p:dataTable ... value="#{mainEntityController.selectedMainEntity.wordList}"... />
要：
<p:dataTable ... value="#{mainEntityController.wordList}"... />
只有这样我才能按照我的预期工作。