大虾们:
小弟最近刚开始使用Jsp编写网络程序,来实现一个网站的功能,一系列工作做的都不错,但是老是出现一个问题,让我很烦恼!
小弟使用的是Windows 2000 server操作系统,配置J2SDK+Tomcat5.0+MySQL4.1的环境配置,但是呢,当使用的时候,如果点击次数过多的时候,经常出现一个错误,这个错误我将粘贴在回帖上,请大虾们帮帮忙,我真的很急切的解决这个问题!
小弟最近刚开始使用Jsp编写网络程序,来实现一个网站的功能,一系列工作做的都不错,但是老是出现一个问题,让我很烦恼!
小弟使用的是Windows 2000 server操作系统,配置J2SDK+Tomcat5.0+MySQL4.1的环境配置,但是呢,当使用的时候,如果点击次数过多的时候,经常出现一个错误,这个错误我将粘贴在回帖上,请大虾们帮帮忙,我真的很急切的解决这个问题!
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:372)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
root cause java.lang.NullPointerException
com.ahsw.myweb.DBConnect.<init>(DBConnect.java:28)
com.ahsw.myweb.bpo.UserBPO.getBranch(UserBPO.java:398)
org.apache.jsp.myweb.content.content_005flist_jsp._jspService(content_005flist_jsp.java:117)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
note The full stack trace of the root cause is available in the Apache Tomcat/5.0.28 logs.
--------------------------------------------------------------------------------Apache Tomcat/5.0.28
DBConnect的init方法中出现了空指针,就在源文件的28行。仔细查查吧。
HTTP Status 500 - 是Java运行环境发生错误
java.lang.NullPointerException是null错误。
com.ahsw.myweb.DBConnect
HTTP Status 500 - --------------------------------------------------------------------------------type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: org.apache.jasper.JasperException: org.apache.jasper.JasperException: Unable to load class for JSP
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:565)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:354)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
root cause org.apache.jasper.JasperException: org.apache.jasper.JasperException: Unable to load class for JSP
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:160)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:326)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
root cause org.apache.jasper.JasperException: Unable to load class for JSP
org.apache.jasper.JspCompilationContext.load(JspCompilationContext.java:600)
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:148)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:326)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
root cause java.lang.ClassNotFoundException: org.apache.jsp.sql_005ftest_jsp
java.net.URLClassLoader$1.run(Unknown Source)
java.security.AccessController.doPrivileged(Native Method)
java.net.URLClassLoader.findClass(Unknown Source)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:134)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:66)
org.apache.jasper.JspCompilationContext.load(JspCompilationContext.java:598)
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:148)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:326)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.1 logs.
--------------------------------------------------------------------------------Apache Tomcat/6.0.1
<%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.sql.*"%>
<html>
<body>
<% Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();
String url="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=pp";
String user="sa";
String passord="sa";
Connection conn=DriverManager.getConnection(url,user,password);
Statement stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
String sql="select * from test";
ResultSet rs=stmt.executeQuery(sql);
while(rs.next()) {%>
您的第一个字段的内容为:<%=rs.getString(1)%>
您的第二个字段的内容为:<%=rs.getString(2)%>
<% } %>
<%out.print("数据库操作成功,恭喜你!");%>
<%rs.close();
stmt.close();
conn.close();
%>
</body>
</html>