javamail利用servlet发送邮件

javax.naming.NamingException: Cannot create resource instance at org.apache.naming.factory.ResourceFactory.getObjectInstance(ResourceFactory.java:132) at javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:304) at org.apache.naming.NamingContext.lookup(NamingContext.java:792) at org.apache.naming.NamingContext.lookup(NamingContext.java:139) at org.apache.naming.NamingContext.lookup(NamingContext.java:780) at org.apache.naming.NamingContext.lookup(NamingContext.java:152) at cn.itcast.javamail3.web.mail.servlets.SendMailServlet.doPost(SendMailServlet.java:55) at cn.itcast.javamail3.web.mail.servlets.SendMailServlet.doGet(SendMailServlet.java:34) at javax.servlet.http.HttpServlet.service(HttpServlet.java:689) at javax.servlet.http.HttpServlet.service(HttpServlet.java:802) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:825) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:743) at org.apache.tomcat.(PoolTcpEndpoint.java:527) at org.apache.tomcat.(LeaderFollowerWorkerThread.java:80) at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684) at java.lang.Thread.run(Thread.java:619)