I am a Java web beginner, poorly understood, in this respect to the reference book in gourd painting gourd ladle let's just go forward step by step, but these days don't know what is accidentally changed files, can run projects have appeared before Java lang. NoClassDefFoundError: javax.mail/servlet/servlet error, baidu for a long time but could not find the answer, is desperate to ask bosses


HTTP status 500 - internal server error


Type of abnormality report

Message Java. Lang. NoClassDefFoundError: javax.mail/servlet/servlet

Description the server encountered an unexpected situation, prevent it to complete the request,

Exceptions to the
Javax.mail. Servlet. ServletException: Java. Lang. NoClassDefFoundError: javax.mail/servlet/servlet
Org. Apache. Jasper. Servlet. JspServlet. Service (348) JspServlet. Java:
Javax.mail. Servlet. HTTP. HttpServlet. Service (HttpServlet. Java: 728)
Org, apache tomcat, websocket server. WsFilter. DoFilter (WsFilter. Java: 52)



Root causes,
Java. Lang. NoClassDefFoundError: javax.mail/servlet/servlet
Java. Lang. This defineClass1 (Native Method)
Java. Lang. This. DefineClass (763). This Java:
Java. Security. SecureClassLoader. DefineClass (SecureClassLoader. Java: 142)
Java.net.URLClassLoader.defineClass URLClassLoader. Java: (467)
Java.net.URLClassLoader.access$100 URLClassLoader. Java: (73)
Java.net.URLClassLoader$1.run URLClassLoader. Java: (368)
Java.net.URLClassLoader$1.run URLClassLoader. Java: (362)
Java. Security. The AccessController. DoPrivileged (Native Method)
Java.net.URLClassLoader.findClass URLClassLoader. Java: (361)
Java. Lang. This. LoadClass (424). This Java:
Java. Lang. This. LoadClass (357). This Java:
Java. Lang. This defineClass1 (Native Method)
Java. Lang. This. DefineClass (763). This Java:
Java. Security. SecureClassLoader. DefineClass (SecureClassLoader. Java: 142)
Java.net.URLClassLoader.defineClass URLClassLoader. Java: (467)
Java.net.URLClassLoader.access$100 URLClassLoader. Java: (73)
Java.net.URLClassLoader$1.run URLClassLoader. Java: (368)
Java.net.URLClassLoader$1.run URLClassLoader. Java: (362)
Java. Security. The AccessController. DoPrivileged (Native Method)
Java.net.URLClassLoader.findClass URLClassLoader. Java: (361)
Java. Lang. This. LoadClass (424). This Java:
Java. Lang. This. LoadClass (411). This Java:
Sun. Misc. The Launcher $AppClassLoader. LoadClass (331). The Launcher Java:
Java. Lang. This. LoadClass (411). This Java:
Java. Lang. This. LoadClass (357). This Java:
Java. Lang. This defineClass1 (Native Method)
Java. Lang. This. DefineClass (763). This Java:
Java. Security. SecureClassLoader. DefineClass (SecureClassLoader. Java: 142)
Java.net.URLClassLoader.defineClass URLClassLoader. Java: (467)
Java.net.URLClassLoader.access$100 URLClassLoader. Java: (73)
Java.net.URLClassLoader$1.run URLClassLoader. Java: (368)
Java.net.URLClassLoader$1.run URLClassLoader. Java: (362)
Java. Security. The AccessController. DoPrivileged (Native Method)
Java.net.URLClassLoader.findClass URLClassLoader. Java: (361)
Java. Lang. This. LoadClass (424). This Java:
Java. Lang. This. LoadClass (357). This Java:
Java. Lang. Class. ForName0 (Native Method)
Java. Lang. Class.forname (348) Class. Java:
Org. Apache. Catalina. Loader. WebappClassLoaderBase. LoadClass (WebappClassLoaderBase. Java: 1937)
Org. Apache. Catalina. Loader. WebappClassLoaderBase. LoadClass (WebappClassLoaderBase. Java: 1795)
Org. Apache. Jasper. Servlet. JasperLoader. LoadClass (JasperLoader. Java: 126)
Org. Apache. Jasper. Servlet. JasperLoader. LoadClass (JasperLoader. Java: 63)
Java. Lang. This defineClass1 (Native Method)
Java. Lang. This. DefineClass (763). This Java:
Java. Security. SecureClassLoader. DefineClass (SecureClassLoader. Java: 142)
Java.net.URLClassLoader.defineClass URLClassLoader. Java: (467)
Java.net.URLClassLoader.access$100 URLClassLoader. Java: (73)
Java.net.URLClassLoader$1.run URLClassLoader. Java: (368)
Java.net.URLClassLoader$1.run URLClassLoader. Java: (362)
Java. Security. The AccessController. DoPrivileged (Native Method)
Java.net.URLClassLoader.findClass URLClassLoader. Java: (361)
Org. Apache. Jasper. Servlet. JasperLoader. LoadClass (JasperLoader. Java: 132)
Org. Apache. Jasper. Servlet. JasperLoader. LoadClass (JasperLoader. Java: 63)
Org. Apache. Jasper. Servlet. JspServletWrapper. GetServlet (JspServletWrapper. Java: 193)
Org. Apache. Jasper. Servlet. JspServletWrapper. Service (414) JspServletWrapper. Java:
Org. Apache. Jasper. Servlet. JspServlet. ServiceJspFile (JspServlet. Java: 395)
Org. Apache. Jasper. Servlet. JspServlet. Service (339) JspServlet. Java:
Javax.mail. Servlet. HTTP. HttpServlet. Service (HttpServlet. Java: 728)
Org, apache tomcat, websocket server. WsFilter. DoFilter (WsFilter. Java: 52)



Root causes,
Java. Lang. ClassNotFoundException: javax.mail. Servlet. Servlet
Java.net.URLClassLoader.findClass URLClassLoader. Java: (381)
Java. Lang. This. LoadClass (424). This Java:
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