相关疑难解决方法(0)

昨天我看到了一个关于Java Server Faces 2.0的演示文稿,虽然我现在是一个快乐的ASP.NET MVC/jQuery开发人员,但它看起来确实令人印象深刻.我最喜欢JSF的是大量支持AJAX的UI组件,这些组件似乎比ASP.NET MVC更快,特别是在AJAX重型站点上.集成测试看起来也很不错.

由于演示文稿只强调了JSF的优点,我也想听听另一方面的意见.

所以我的问题是:

• Java Server Faces 2.0的主要缺点是什么？
• 什么可能使JSF开发人员考虑使用ASP.NET MVC而不是JSF？

我正在阅读JSF,它是一个UI框架并提供了一些UI组件.但它与jQueryUI,AngularJS,ExtJS甚至纯HTML,CSS和JavaScript中可用的组件数量有何不同或更好.

为什么有人要学习JSF？

我从JSF2.0开始看到,Facelets视图定义语言是首选的视图定义语言,而不是作为遗留后退而被弃用的JSP.我想理解为什么Facelets比JSF2.0以后的视图定义语言更优先于JSP？我知道JSP也有一些模板行为,这是采用Facelets的主要驱动点.

PS:我在stackoverflow上经历过这篇文章,但我不认为它回答了我的问题.因此将此作为单独的问题发布.

我在尝试在Tomcat 6上运行我的项目时遇到此问题:

SEVERE: Servlet.service() for servlet jsp threw exception
java.lang.RuntimeException: Cannot find FacesContext
        at javax.faces.webapp.UIComponentClassicTagBase.getFacesContext(UIComponentClassicTagBase.java:2122)
        at javax.faces.webapp.UIComponentClassicTagBase.setJspId(UIComponentClassicTagBase.java:1933)
        at org.apache.jsp.Contato_jsp._jspx_meth_f_005fview_005f0(Contato_jsp.java:125)
        at org.apache.jsp.Contato_jsp._jspService(Contato_jsp.java:102)
        at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:386)
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:470)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)

.......

我已经将jsf-impl.jar,jsf-api.jar和jstl-1.2.jar添加到了类路径中.还有其他的lib吗？在下面你可以检查web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" 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-app_2_5.xsd">

    <context-param>
        <param-name>javax.faces.PROJECT_STAGE</param-name>
        <param-value>Development</param-value>
    </context-param>
    <servlet>
        <servlet-name>Faces Servlet</servlet-name>
        <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>Faces …