![](/img/trans.png)
[英]Getting error While running a simple Struts 2 application.I am using struts 2.5.10.1
[英]Getting error while running a simple JSF application
我在嘗試運行基本的JSF應用程序時遇到異常。 我使用JSF1.1,JDK 6和tomcat 6.0.18相同。
例外
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: Error testing property 'lastname' in bean of type null
javax.faces.webapp.FacesServlet.service(FacesServlet.java:209)
root cause
javax.faces.el.PropertyNotFoundException: Error testing property 'lastname' in bean of type null
com.sun.faces.el.PropertyResolverImpl.getType(PropertyResolverImpl.java:342)
com.sun.faces.el.impl.ArraySuffix.getType(ArraySuffix.java:240)
com.sun.faces.el.impl.ComplexValue.getType(ComplexValue.java:208)
com.sun.faces.el.ValueBindingImpl.getType(ValueBindingImpl.java:345)
com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getConvertedValue(HtmlBasicInputRenderer.java:111)
javax.faces.component.UIInput.getConvertedValue(UIInput.java:713)
javax.faces.component.UIInput.validate(UIInput.java:638)
javax.faces.component.UIInput.executeValidate(UIInput.java:849)
javax.faces.component.UIInput.processValidators(UIInput.java:412)
javax.faces.component.UIForm.processValidators(UIForm.java:170)
javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:912)
javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:342)
com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:78)
com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:200)
com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:90)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:197)
以下是我為同一文件創建的文件:
//jsfmbean.jsp
<!DOCTYPE HTML PUBLIC
"-//W3C//DTD HTML 4.01 Transitional//EN">
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>
<f:view>
<html>
<body bgcolor="cyan">
<h:form id="form1" >
<h:inputText id="text1" value="#{text2}" />
<h:inputText id="text2" value="#{player.lastname}" />
<h:commandButton action="success" value="success" />
<h:commandButton action="#{player.changeName}" value="failure" />
</h:form>
</body>
</html>
</f:view>
//faces-config.xml
<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE faces-config PUBLIC
"-//Sun Microsystems, Inc.//DTD JavaServer Faces Config 1.1//EN"
"http://java.sun.com/dtd/web-facesconfig_1_1.dtd">
<faces-config>
<application>
<locale-config>
<default-locale>en</default-locale>
</locale-config>
</application>
<navigation-rule>
<from-view-id>
/jsfevent.jsp
</from-view-id>
<navigation-case>
<from-outcome>success</from-outcome>
<to-view-id>/mathew.jsp</to-view-id>
</navigation-case>
<navigation-case>
<from-outcome>failure</from-outcome>
<to-view-id>/amy.jsp</to-view-id>
</navigation-case>
</navigation-rule>
<navigation-rule>
<from-view-id>/jsfmbean.jsp</from-view-id>
<navigation-case>
<from-outcome>success</from-outcome>
<to-view-id>/mathew.jsp</to-view-id>
</navigation-case>
</navigation-rule>
<managed-bean>
<managed-bean-name>player</managed-bean-name>
<managed-bean-class>
ourdemo.player
</managed-bean-class>
<managed-bean-scope>
session
</managed-bean-scope>
<managed-property>
<property-name>firstname</property-name>
<property-type>java.lang.String</property-type>
<value>Mahatma</value>
</managed-property>
<managed-property>
<property-name>lastname</property-name>
<property-type>java.lang.String</property-type>
<value>Gandhiji</value>
</managed-property>
</managed-bean>
</faces-config>
//Player.java
package ourdemo;
import javax.faces.context.*;
import javax.faces.component.*;
import javax.faces.validator.*;
public class Player
{
String firstname ;
String lastname ;
public void setFirstname(String a)
{
firstname=a;
}
public String getFirstname()
{
return firstname;
}
//----------
public void setLastname(String b)
{
lastname=b;
}
public String getLastname()
{
return lastname;
}
//-------------------
public void changeName()
{
lastname= firstname+" "+lastname;
}
}
請幫忙 ...
#{player}
指向的Bean尚未正確初始化,因此#{player.lastname}
引發NullPointerException。
Java區分大小寫。 您已經創建了具有完全合格的類名ourdemo.Player
的托管bean,但是您在faces-config.xml
中將bean聲明為ourdemo.player
(請注意,小寫字母p
代替大寫字母P
)。 這樣,JSF無法找到並創建bean類,從而導致#{player}
為null
,從而導致此異常。
相應地修復它:
<managed-bean>
<managed-bean-name>player</managed-bean-name>
<managed-bean-class>ourdemo.Player</managed-bean-class>
<managed-bean-scope>session</managed-bean-scope>
</managed-bean>
與具體問題無關 :我完全同意Arjan Tijms的問題評論:盡可能使用JSF 2.0或更高版本。 JSF 1.1已過時5年,並且有許多缺點。 如果由於業務限制而使用JSF 1.1,請說服您的經理。 或者,如果您正在使用JSF 1.1,因為您正在閱讀過時的書籍/教程,則將它們扔掉並閱讀正確的書籍/教程。
您的faces-config.xml錯誤。
類名聲明必須與
<managed-bean-class>
ourdemo.Player
</managed-bean-class>
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.