大家好，我是 jsp 的新手，这是我学习托管 bean、导航规则和其他东西的第一个项目，但我看不出这里有什么问题。我所有的代码都是那些。请帮助我，因为我要疯了才能找到这个。错误是 /pages/login.jsp(31,2) '#{employee.username}' 目标无法访问，标识符 'employee' 解析为 null
雇员.java
package com;
public class Employee {
private String username;
private String password;
private String name;
private String department;
private int age;
private double salary;
private boolean canEdit;
public Employee (String username,String password,String name,String department,int age,double salary){
this.username = username;
this.password = password;
this.name = name;
this.department = department;
this.age = age;
this.salary = salary;
canEdit = false;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDepartment() {
return department;
}
public void setDepartment(String department) {
this.department = department;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
public boolean isCanEdit() {
return canEdit;
}
public void setCanEdit(boolean canEdit) {
this.canEdit = canEdit;
}
}
用户数据.java
package com;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
public class UserData implements Serializable {
private static final long serialVersionUID = 1L;
private String username;
private String password;
private String name;
private String department;
private int age;
private double salary;
private static final ArrayList<Employee> employees
= new ArrayList<Employee>(Arrays.asList(
new Employee("1","1","John", "Marketing", 30,2000.00),
new Employee("2","2","Robert", "Marketing", 35,3000.00),
new Employee("3","3","Mark", "Sales", 25,2500.00),
new Employee("4","4","Chris", "Marketing", 33,2500.00),
new Employee("5","5","Peter", "Customer Care", 20,1500.00)
));
public ArrayList<Employee> getEmployees() {
return employees;
}
public String addEmployee() {
Employee employee = new Employee(username,password,name,department,age,salary);
employees.add(employee);
return null;
}
public String deleteEmployees(Employee employee) {
employees.remove(employee);
return null;
}
public String editEmployee(Employee employee){
employee.setCanEdit(true);
return null;
}
public String saveEmployees(){
for (Employee employee : employees){
employee.setCanEdit(false);
}
return null;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDepartment() {
return department;
}
public void setDepartment(String department) {
this.department = department;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
public String loginAction(){
String action = null;
if (username.equalsIgnoreCase("admin") && password.equalsIgnoreCase("a"))
action = "loginAdmin";
else
action = "loginUser";
return action;
}
}
主页.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="f" uri="http://java.sun.com/jsf/core"%>
<%@ taglib prefix="h" uri="http://java.sun.com/jsf/html"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<style>
.employeeTable{
border-collapse:collapse;
border:1px solid #000000;
}
.employeeTableHeader{
text-align:center;
background:none repeat scroll 0 0 #B5B5B5;
border-bottom:1px solid #000000;
padding:2px;
}
.employeeTableOddRow{
text-align:center;
background:none repeat scroll 0 0 #FFFFFFF;
}
.employeeTableEvenRow{
text-align:center;
background:none repeat scroll 0 0 #D3D3D3;
}</style>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>DataTable</title>
</head>
<body><f:view>
<h2>DataTable Example</h2>
<h:form>
<h:dataTable value="#{userData.employees}" var="employee"
styleClass="employeeTable"
headerClass="employeeTableHeader"
rowClasses="employeeTableOddRow,employeeTableEvenRow">
<h:column>
<f:facet name="header">Name</f:facet>
<h:inputText id="name" value="#{employee.name}"></h:inputText>
</h:column>
<h:column>
<f:facet name="header">Department</f:facet>
<h:inputText id="department" value="#{employee.department}"></h:inputText>
</h:column>
<h:column>
<f:facet name="header">Age</f:facet>
<h:inputText id="age" value="#{employee.age}"></h:inputText>
</h:column>
<h:column>
<f:facet name="header">Salary</f:facet>
<h:inputText id="salary" value="#{employee.salary}"></h:inputText>
</h:column>
<h:column>
<h:commandButton value="Delete"
action="#{userData.deleteEmployee}" >
<f:setPropertyActionListener
target="#{userData.employees}" value="#{employee}" />
</h:commandButton>
</h:column>
</h:dataTable>
<h3>Add Employee</h3>
<hr/>
<table>
<tr>
<td>Name :</td>
<td><h:inputText size="10" value="#{userData.name}" /></td>
</tr>
<tr>
<td>Department :</td>
<td><h:inputText size="20" value="#{userData.department}" /></td>
</tr>
<tr>
<td>Age :</td>
<td><h:inputText size="5" value="#{userData.age}" /></td>
</tr>
<tr>
<td>Salary :</td>
<td><h:inputText size="5" value="#{userData.salary}" /></td>
</tr>
<tr>
<td> </td>
<td><h:commandButton value="Add Employee"
action="#{userData.addEmployee}" /></td>
</tr>
</table>
</h:form></f:view>
</body>
</html>
登录.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<f:view>
<b><h:outputText value="USER Login"> </h:outputText></b>
<p>
<h:messages style="color: blue"/></p>
<h:form>
<h:panelGrid columns="2">
<h:dataTable value="#{userData.employees}" var="employee"></h:dataTable>
<%--
<h:dataTable value="#{userData.employees}" var="employee"></h:dataTable>
<h:column>
<h:outputText id="header" value="username"></h:outputText>
<h:inputText id="username" value="#{employee.username}"></h:inputText>
<br><br>
<h:outputText id="header" value="password"></h:outputText>
<h:inputText id="password" value="#{employee.password}"></h:inputText>
</h:column>
--%>
<h:column>
<h:outputText value="username :"></h:outputText>
<h:inputText id="username" value="#{employee.username}">
</h:inputText>
<br>
<h:outputText value="password :"></h:outputText>
<h:inputText id="password" value="#{employee.password}" >
</h:inputText>
</h:column>
</h:panelGrid>
<h:commandButton value="Login" action="#{userData.loginAction}"></h:commandButton><br/>
<h:outputLink value="pages/sign.jsf"><h:outputText value="Go for Sign up."/></h:outputLink>
</h:form>
</f:view>
</body>
</html>
面孔-config.xml
<?xml version="1.0" encoding="UTF-8"?>
<faces-config version="1.2" xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xi="http://www.w3.org/2001/XInclude"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_1_2.xsd">
<managed-bean>
<managed-bean-name>userData</managed-bean-name>
<managed-bean-class>com.UserData</managed-bean-class>
<managed-bean-scope>session</managed-bean-scope>
</managed-bean>
<navigation-rule>
<from-view-id>/pages/login.jsp</from-view-id>
<navigation-case>
<from-outcome>loginAdmin</from-outcome>
<to-view-id>/pages/home.jsp</to-view-id>
</navigation-case>
<navigation-case>
<from-outcome>loginUser</from-outcome>
<to-view-id>/pages/welcome.jsp</to-view-id>
</navigation-case>
</navigation-rule>
</faces-config>
索引.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<jsp:forward page="/pages/login.jsf" />
</body>
</html>
错误信息
11:45:47,704 WARN [lifecycle] executePhase(PROCESS_VALIDATIONS 3,com.sun.faces.context.FacesContextImpl@23ccb9) threw exception
javax.faces.FacesException: /pages/login.jsp(31,2) '#{employee.username}' Target Unreachable, identifier 'employee' resolved to null
at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:108)
at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:244)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:179)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:446)
at java.lang.Thread.run(Unknown Source)
Caused by: org.apache.jasper.el.JspPropertyNotFoundException: /pages/login.jsp(31,2) '#{employee.username}' Target Unreachable, identifier 'employee' resolved to null
at org.apache.jasper.el.JspValueExpression.getType(JspValueExpression.java:61)
at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getConvertedValue(HtmlBasicInputRenderer.java:81)
at javax.faces.component.UIInput.getConvertedValue(UIInput.java:934)
at javax.faces.component.UIInput.validate(UIInput.java:860)
at javax.faces.component.UIInput.executeValidate(UIInput.java:1065)
at javax.faces.component.UIInput.processValidators(UIInput.java:666)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1033)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1033)
at javax.faces.component.UIForm.processValidators(UIForm.java:229)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1033)
at javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:662)
at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:100)
... 21 more
11:45:47,704 ERROR [[Faces Servlet]] Servlet.service() for servlet Faces Servlet threw exception
org.apache.jasper.el.JspPropertyNotFoundException: /pages/login.jsp(31,2) '#{employee.username}' Target Unreachable, identifier 'employee' resolved to null
at org.apache.jasper.el.JspValueExpression.getType(JspValueExpression.java:61)
at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getConvertedValue(HtmlBasicInputRenderer.java:81)
at javax.faces.component.UIInput.getConvertedValue(UIInput.java:934)
at javax.faces.component.UIInput.validate(UIInput.java:860)
at javax.faces.component.UIInput.executeValidate(UIInput.java:1065)
at javax.faces.component.UIInput.processValidators(UIInput.java:666)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1033)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1033)
at javax.faces.component.UIForm.processValidators(UIForm.java:229)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1033)
at javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:662)
at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:100)
at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:244)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:179)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:446)
at java.lang.Thread.run(Unknown Source)