在用tomcat时浏览网页时出现这样一些代码type Exception report message description The server encountered an internal error () that prevented it from fulfilling this request. exception java.lang.NullPointerException
bean.DBClass.executeQuery(DBClass.java:109)
UserLogin.doGet(UserLogin.java:21)
UserLogin.doPost(UserLogin.java:42)
javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.23 logs. 求助,这是什么原因呢
bean.DBClass.executeQuery(DBClass.java:109)
UserLogin.doGet(UserLogin.java:21)
UserLogin.doPost(UserLogin.java:42)
javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.23 logs. 求助,这是什么原因呢
还是代码的问题呢
却没有给它传具体的值