Question

Java 建立WEB项目。500报错。

HTTP Status 500 - Error instantiating servlet class
mydatabase.SelectServlet

type Exception report

message Error instantiating servlet class
mydatabase.SelectServlet

description The server encountered an internal error that prevented
it from fulfilling this request.

exception
javax.servlet.ServletException: Error instantiating servlet class mydatabase.SelectServlet
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:315)
java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
java.lang.Thread.run(Unknown Source)
求问是什么错？？
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/plain;charset=UTF-8");
PrintWriter out = response.getWriter();
String RES="";
String type=request.getParameter("radio");
String key=request.getParameter("text");
if(type.equals("student")){
RES=DBOperator.getstudent(key);
System.out.println(RES);
}
if(type.equals("teacher")){
RES=DBOperator.getteacher(key);
System.out.println(RES);
}
}
}
前面都是自动生成的，这里是自己写的。

Answer 1

Error instantiating servlet class mydatabase.SelectServlet
无法初始化这个SelcetServlet
你可以把这个代码注释掉，看还有错误吗》？
RES=DBOperator.getstudent(key);
与数据库相关东西全部注释掉
你的给报错异常信息不全啊

Answer 2

报500错误一般是你代码错误，可以去代码页面查看是否有红色的X，Error instantiating servlet class mydatabase.mydatabase类实例化错误，根据你下面的apache和mydatabase，可能是数据库连接那一部分出问题。
希望能帮到你！

追问

没有红色的叉。。。

Answer 3

贴代码！！！

Answer 4

吧tomcat中servletAPI加到项目当中去

Answer 5

说你实例化mydatabase.SelectServlet时出错，需要贴出相关部分的代码才能分析具体原因！