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Java 托管Bean不工作：调用NotingMB文件中的save函数时出现空指针异常

java jsf primefaces

Java 托管Bean不工作：调用NotingMB文件中的save函数时出现空指针异常,java,jsf,primefaces,Java,Jsf,Primefaces,我正在使用Eclipse以及jsf和MVC框架。。保存从Xhtml文件调用的bean文件函数时。。它显示错误：notingMB.save上出现空指针异常 代码： xhtml文件 CreateFileDialog.xhtml <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html x

我正在使用Eclipse以及jsf和MVC框架。。保存从Xhtml文件调用的bean文件函数时。。它显示错误：notingMB.save上出现空指针异常

代码： xhtml文件 CreateFileDialog.xhtml

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:ui="http://java.sun.com/jsf/facelets"
    xmlns:h="http://java.sun.com/jsf/html"
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:p="http://primefaces.org/ui">
<h:body>
    <h:form id="CreateFileDialogForm" prependId="false">
    <p:dialog widgetVar="CreateFileDialogWidget"
        id="CreateFileDialogId" height="500" width="500" modal="true"
        closable="true" draggable="true" resizable="false" header="Create File">


            <h:panelGrid columns="2" cellpadding="5">

            <h:outputLabel for="Subject" value="#{bundle.subject}"/>
                <h:inputText id="Subject" value="#{fileMB.info.subject}" required="true"/>   

                <h:outputLabel for="fileRefNo" value="File-Ref-No"/>
                <h:inputText id="fileRefNo" value="#{fileMB.info.fileRefNo}" required="true"/>   



                 <h:outputText value="Classification" />
                    <p:selectOneRadio id="Classi" value="#{fileMB.info.classification}">
                    <f:selectItem itemLabel="Normal" itemValue="Normal" />
                    <f:selectItem itemLabel="Restricted" itemValue="Restricted" />
                    <f:selectItem itemLabel="Confidential" itemValue="Confidential" />
                    <f:selectItem itemLabel="Secret" itemValue="Secret" />
                    <f:selectItem itemLabel="TopSecret" itemValue="Top Secret" />
                    </p:selectOneRadio>

                    <h:outputText value="Priority" />
                    <p:selectOneRadio id="prior" value="#{fileMB.info.priority}">
                    <f:selectItem itemLabel="Normal" itemValue="Normal" />
                    <f:selectItem itemLabel="High" itemValue="High" />
                    <f:selectItem itemLabel="Medium" itemValue="Medium" />
                    <f:selectItem itemLabel="Low" itemValue="Low" />
                    </p:selectOneRadio>
                 <h:outputText for="Description" value="#{bundle.briefDescription}" />
                 <p:inputTextarea id="Description" value="#{fileMB.info.description}" rows="5" cols="30" counter="display" maxlength="10" counterTemplate="{0} characters remaining." autoResize="false" />
                 <h:outputText id="display" />
                 <br></br>

                 <p:commandButton value="Add Comment" icon="ui-icon-plus"
                         onclick="CreateComentDialogWidget.show();"/> 
                 <br></br>

                 <br></br>
                <p:commandButton value="create" actionListener="#{fileMB.save}" />
                <p:commandButton value="cancel" icon="ui-icon-cancel"
                    onclick="CreateFileDialogWidget.hide();" type="button" />

            </h:panelGrid>

    </p:dialog>
    </h:form>
    <ui:include src="/pages/protected/filling/File/CreateComentDialog.xhtml" />

</h:body>
</html>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:ui="http://java.sun.com/jsf/facelets"
    xmlns:h="http://java.sun.com/jsf/html"
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:p="http://primefaces.org/ui">
<h:body>
    <h:form id="CreateComentDialogForm" prependId="false">
    <p:dialog widgetVar="CreateComentDialogWidget"
        id="CreateComentDialogId" height="500" width="500" modal="true"
        closable="true" draggable="true" resizable="false" header="Create File">


            <h:panelGrid columns="2" cellpadding="5">
            <h:outputLabel for="coment" value="write coment"/>
               <p:inputTextarea id="coment" value="#{notingMB.note.comment}" rows="5" cols="30" counter="display2" maxlength="50" counterTemplate="{0} characters remaining." autoResize="false" />
                 <h:outputText id="display2" />
                 <br></br>

                   <p:commandButton value="create" actionListener="#{notingMB.save}" />
                   <p:commandButton value="cancel" icon="ui-icon-cancel"
                    onclick="CreateComentDialogWidget.hide();" type="button" />

               </h:panelGrid>
               </p:dialog>
               </h:form>

               </h:body>
               </html>
actionListener属性将接受javax.faces.event.ActionEvent参数

你应该改变

public void save() {

    System.out.println("before save");
    System.out.println(note.getComment());
    controller.saveComment(note);
    System.out.println("after save");
}
到

package com.managedBean.Filling;

import java.io.Serializable;

import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;

import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;

import com.controller.Controller;
import com.managedBean.BaseMB;
import com.model.filling.Noting;
@ManagedBean(name="notingMB")
@SessionScoped
public class NotingMB extends BaseMB implements Serializable
{
    public static final long serialVersionUID = 1L;
    public static final Logger log = LogManager.getLogger(NotingMB.class.getName());

    private Noting note;




    public Noting getNote() {
        return note;
    }

    public void setNote(Noting note) {
        this.note = note;
    }



    public NotingMB()
    {

        this.note = new Noting();

        //controller = Controller.getInstance();
    }

    public void save()
    {

        System.out.println("before save");
        System.out.println(note.getComment());
        controller.saveComment(note);
        System.out.println("after save");
    }
}

public void save() {

    System.out.println("before save");
    System.out.println(note.getComment());
    controller.saveComment(note);
    System.out.println("after save");
}

public void save(ActionEvent event) {

    System.out.println("before save");
    System.out.println(note.getComment());
    controller.saveComment(note);
    System.out.println("after save");
}