jsf-2 - 行编辑在数据表primefaces中不起作用

Question

在编辑数据表值期间，屏幕和监听器方法中的值不会更新。监听器方法:

public void onEdit(RowEditEvent event) throws ClassNotFoundException, SQLException
{
    Employee e=(Employee) event.getObject();
    name=e.getName();
    department=e.getDepartment();
    salary=e.getSalary();
    place=e.getPlace();
          ......
           ..... update query
}

我只得到选定的对象及其值，而不是更新的值。

这是我的数据表 XHTML:

<h:form id="form">
    <p:growl id="messages" showDetail="true" />

    <p:dataTable var="e" value="#{employees.eList}" id="elist1"
        editable="true">
        <f:facet name="header">
        In-Cell Editing
    </f:facet>

        <p:ajax event="rowEdit" listener="#{employees.onEdit}"
            update=":form:messages" />
        <p:ajax event="rowEditCancel" listener="#{employees.onCancel}"
            update=":form:messages" />

        <p:column headerText="name" style="width:30%">
            <p:cellEditor>
                <f:facet name="output">
                    <h:outputText value="#{e.name}" />
                </f:facet>
                <f:facet name="input">
                    <h:inputText value="#{e.name}" style="width:100%" />
                </f:facet>
            </p:cellEditor>
        </p:column>

        <p:column headerText="department" style="width:20%">
            <p:cellEditor>
                <f:facet name="output">
                    <h:outputText value="#{e.department}" />
                </f:facet>
                <f:facet name="input">
                    <h:inputText value="#{e.department}" style="width:100%"
                        label="department" />
                </f:facet>
            </p:cellEditor>
        </p:column>

        <p:column headerText="salary" style="width:20%">
            <p:cellEditor>
                <f:facet name="output">
                    <h:outputText value="#{e.salary}" />
                </f:facet>
                <f:facet name="input">
                    <h:inputText value="#{e.salary}" style="width:100%" label="salary" />
                </f:facet>
            </p:cellEditor>
        </p:column>

        <p:column headerText="place" style="width:20%">
            <p:cellEditor>
                <f:facet name="output">
                    <h:outputText value="#{e.place}" />
                </f:facet>
                <f:facet name="input">
                    <h:inputText value="#{e.place}" style="width:100%" label="place" />
                </f:facet>
            </p:cellEditor>
        </p:column>



        <p:column style="width:6%">
            <p:rowEditor />
        </p:column>

    </p:dataTable>

</h:form>

这是我的托管 bean:

@ManagedBean(name = "employees")
@ViewScoped
public class UserData  
{
    // properties
    private String name;
    private String department;
    private String salary;
    private String place;
    private ArrayList<Employee> eList;
    private Employee selectedemp;



    private void clear()
    {
        name="";
        department="";
        salary="";
        place="";
    }

//returning all employees   
    public ArrayList<Employee> geteList() throws ClassNotFoundException, SQLException {
        Connection conn=DbConnection.connectFunc();
        Statement stmt=conn.createStatement();
        String sql="select * from employee";
        ResultSet rs=stmt.executeQuery(sql);
        eList=new ArrayList<Employee>();
        while(rs.next())
        {
            Employee emp=new Employee();
            emp.setName(rs.getString(2));
            emp.setDepartment(rs.getString(3));
            emp.setSalary(rs.getString(4));
            emp.setPlace(rs.getString(5));
            eList.add(emp);
        }
        return eList;
    }
public void onEdit(RowEditEvent event) throws ClassNotFoundException, SQLException
    {

    Employee e=(Employee) event.getObject();
     name=e.getName();
        System.out.println(name);
        department=e.getDepartment();
        System.out.println(department);
        salary=e.getSalary();
        System.out.println(salary);
        place=e.getPlace();
        System.out.println(place);

        Connection conn=DbConnection.connectFunc();
        Statement stmt=conn.createStatement();
        String sql="update employee set department='"+department+"',salary='"+salary+"',place='"+place+"'where name='"+name+"'";
        int i=stmt.executeUpdate(sql);
        if(i!=0)
        {
            FacesContext context=FacesContext.getCurrentInstance();
            context.addMessage(null, new FacesMessage("updated  successfully"));
        }
        conn.close();
    }
//onCancel
    public void onCancel(RowEditEvent event)
    {

    }
...setter and getters

如果我使用 View 范围，则会发生以下异常:

HTTP Status 500 -

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

java.io.NotSerializableException: com.solv.datatable.UserData
    java.io.ObjectOutputStream.writeObject0(Unknown Source)
    java.io.ObjectOutputStream.writeObject(Unknown Source)
    java.util.HashMap.writeObject(Unknown Source)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    java.io.ObjectStreamClass.invokeWriteObject(Unknown Source)
    java.io.ObjectOutputStream.writeSerialData(Unknown Source)
    java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source)
    java.io.ObjectOutputStream.writeObject0(Unknown Source)
    java.io.ObjectOutputStream.defaultWriteFields(Unknown Source)
    java.io.ObjectOutputStream.writeSerialData(Unknown Source)
    java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source)
    java.io.ObjectOutputStream.writeObject0(Unknown Source)
    java.io.ObjectOutputStream.writeArray(Unknown Source)
    java.io.ObjectOutputStream.writeObject0(Unknown Source)
    java.io.ObjectOutputStream.writeObject(Unknown Source)
    java.util.HashMap.writeObject(Unknown Source)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    java.io.ObjectStreamClass.invokeWriteObject(Unknown Source)
    java.io.ObjectOutputStream.writeSerialData(Unknown Source)
    java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source)
    java.io.ObjectOutputStream.writeObject0(Unknown Source)
    java.io.ObjectOutputStream.writeObject(Unknown Source)
    com.sun.faces.renderkit.ClientSideStateHelper.doWriteState(ClientSideStateHelper.java:325)
    com.sun.faces.renderkit.ClientSideStateHelper.writeState(ClientSideStateHelper.java:173)
    com.sun.faces.renderkit.ResponseStateManagerImpl.writeState(ResponseStateManagerImpl.java:122)
    com.sun.faces.application.StateManagerImpl.writeState(StateManagerImpl.java:166)
    com.sun.faces.application.view.WriteBehindStateWriter.flushToWriter(WriteBehindStateWriter.java:225)
    com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:419)
    com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:125)
    com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121)
    com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
    javax.faces.webapp.FacesServlet.service(FacesServlet.java:410)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.26 logs.

Answer 1

你的 bean 必须实现接口(interface) Serializable。这就是错误消息所说的

另一个问题是您总是通过 getEList 返回新列表。您可以在某种带有注释 @PostConstruct 的 init 方法中加载您的 ArayList .

@PostConstruct
public void init() {
       //code from getElist()...
}

你的 setter/getter 应该是只返回 eList 的经典 setter/getter 。
通过这种方式，您可以在创建 View 时加载列表。在您的情况下，每次更新都会再次加载列表，这是不好的做法。不要在 getter 中获取数据。编辑对您不起作用，因为您每次都返回一个新列表会丢失更新的值。