java.lang.ClassCastException: org.apache.catalina.util.DefaultAnnotationProcessor cannot be cast to

 

运行程序时，出现异常：

出现异常：

HTTP Status 500 -

---

typeException report

message

descriptionThe server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: java.lang.ClassCastException: org.apache.catalina.util.DefaultAnnotationProcessor cannot be cast to org.apache.AnnotationProcessor
	org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:161)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:338)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

 

root cause

java.lang.ClassCastException: org.apache.catalina.util.DefaultAnnotationProcessor cannot be cast to org.apache.AnnotationProcessor
	org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:151)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:338)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

 

noteThe full stack trace of the root cause is available in the Apache Tomcat/6.0.30 logs.

---

Apache Tomcat/6.0.30

 

原因分析：

Tomcat中catalina.jar和jasper.jar都有AnnotationProcessor接口，所以运行时，就出错了：java.lang.ClassCastException: org.apache.catalina.util.DefaultAnnotationProcess<wbr>or。</wbr>

<wbr></wbr>

异常的解决方法：

在tomcat中的context.xml文件中添加<Loader delegate="true" />！~

<wbr></wbr>

PS：

<wbr>Loader对象可出现在Context中以控制Java类的加载。</wbr>虽然可以改变loadet类，不过一般不会这样做，所以在下面的属性中，我们们列出了标准的属性和“一般”类加载器所接受的属性。

<wbr></wbr>

<wbr><wbr>属性：<span style="word-wrap:normal; word-break:normal; line-height:18px; color:rgb(0,128,0)">className</span>、含义：org.apache.catalina.Loader实现类名、默认值：org.apache.catalina.loader.WebappClassLoader</wbr></wbr>

<wbr></wbr>

<wbr><wbr>属性：<span style="word-wrap:normal; word-break:normal; line-height:18px; color:rgb(0,128,0)">delegate</span>、含义：True代表使用正式的Java代理模式(先询问父类的加载器)；false代表先在Web应用程序中寻找。警告：如果不知道如何处理，则不要改变这一属性值、默认值：FALSE</wbr></wbr>

<wbr></wbr>

<wbr><wbr>属性：<span style="word-wrap:normal; word-break:normal; line-height:18px; color:rgb(0,128,0)">loaderClass</span>、含义：类加载器、默认值：org.apache.catalina.loader.WebappClassLoader</wbr></wbr>

<wbr></wbr>

<wbr><wbr>属性：<span style="word-wrap:normal; word-break:normal; line-height:18px; color:rgb(0,128,0)">reloadable</span>、含义：与Context下的意义相同。这时的值会改写Context中的值、默认值：FALSE</wbr></wbr>

<wbr></wbr>

<wbr><wbr>属性：<span style="word-wrap:normal; word-break:normal; line-height:18px; color:rgb(0,128,0)">workDir</span>、含义：存放临时文件的目录、默认值：CATALINA_BASE下的临时目录(如果不显示设定CATALINA_TOME的值，则是CATALINA_BASE)</wbr></wbr>