如何解决此错误？
Target Unreachable,return null
HTTP Status 500 - /gotit.xhtml @34,49 value="#{bean.nbrp.title}": Target Unreachable, 'nbrp' returned null
gotit.xhtml
<h:head></h:head>
<body>
<rich:panel>
<f:facet name="header">
Actionlistener,Binding,Importing AnotherClasses
</f:facet>
<h3>Todo List</h3>
<f:view>
<h:messages layout="table"></h:messages>
<!-- This form is used to add new todo List -->
<h:form>
<h:commandLink binding="#{bean.addcommand}" action="#{bean.addnew}"
value="Add new Todo" accesskey="a" />
</h:form>
<!-- This form is used to open to enter new Todo list -->
<h:form binding="#{bean.form}" rendered="false">
<h:panelGrid columns="2">
<h:column>
<h:outputText value="Title" />
</h:column>
<h:column>
<h:inputText value="#{bean.nbrp.title}" />
</h:column>
<h:column>
<h:outputText value="Description" />
</h:column>
<h:column>
<h:inputText value="#{bean.nbrp.description}" />
</h:column>
<h:column>
<h:outputText value="Priority" />
</h:column>
<h:column>
<h:selectOneMenu value="#{bean.nbrp.priority}" style="width:127px;color:blue;font-weight:bold;">
<f:selectItem itemValue="one" itemLabel="High"/>
<f:selectItem itemValue="second" itemLabel="Medium" />
<f:selectItem itemValue="three" itemLabel="Low" />
</h:selectOneMenu>
</h:column>
</h:panelGrid>
<h:commandButton value="Save" action="#{bean.save}" />
</h:form>
</f:view>
</rich:panel>
</body>
</html>
BasavaProp.java
包 com.basu; 导入 java.util.Calendar；
public class BasavaProp {
private String id;
private String title;
private String description;
private int priority;
private Calendar duedate;
public BasavaProp(String title,String description,int priority)
{
this.title=title;
this.description=description;
this.priority=priority;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public int getPriority() {
return priority;
}
public void setPriority(int priority) {
this.priority = priority;
}
public Calendar getDuedate() {
return duedate;
}
public void setDuedate(Calendar duedate) {
this.duedate = duedate;
}
}
basavacontrol.java
package com.basu;
import java.util.ArrayList;
import java.util.List;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
import javax.faces.component.UICommand;
import javax.faces.component.UIForm;
@ManagedBean(name="bean")
@RequestScoped
public class basavacontrol {
private List<BasavaProp> list;
public BasavaProp nbrp;
private UIForm form;
private UIForm dataform;
private UICommand addcommand;
public basavacontrol() {
list=new ArrayList<BasavaProp>();
list.add(new BasavaProp("title1", "hi", 2));
list.add(new BasavaProp("chapter2", "i want to learn and earn", 7));
}
public String addnew(){
nbrp=new BasavaProp("", "", 0);
form.setRendered(true);
addcommand.setRendered(false);
return null;
}
public String save()
{
list.add(nbrp);
form.setRendered(false);
addcommand.setRendered(true);
System.out.println("i am inside save method");
return null;
}
public List<BasavaProp> getList() {
return list;
}
public void setList(List<BasavaProp> list) {
this.list = list;
}
public BasavaProp getNbrp() {
return nbrp;
}
public void setNbrp(BasavaProp nbrp) {
this.nbrp = nbrp;
}
public UIForm getForm() {
return form;
}
public void setForm(UIForm form) {
this.form = form;
}
public UIForm getDataform() {
return dataform;
}
public void setDataform(UIForm dataform) {
this.dataform = dataform;
}
public UICommand getAddcommand() {
return addcommand;
}
public void setAddcommand(UICommand addcommand) {
this.addcommand = addcommand;
}
}