关于网友提出的“ 这个简单的问题为什么我搞不定?”问题疑问,本网通过在网上对“ 这个简单的问题为什么我搞不定?”有关的相关答案进行了整理,供用户进行参考,详细问题解答如下:
问题: 这个简单的问题为什么我搞不定?
描述: JSP文件如下:
<%@ page c/>
login
JBuilder Generated JSP
<%ResultSet RS_result;
RS_result=loginBeanId.executeQuery("select * from employee");
String code;
String name;
while(RS_result.next())
{
code=RS_result.getString("code");
name=RS_result.getString("name");
%>
<%=code%> |
<%=name%> |
<%
}
RS_result.close();
%>
javabean文件如下:
package wxsample;
import java.sql.*;
import java.lang.*;
public class LoginBean {
String sDBDriver = "sun.jdbc.odbc.JdbcOdbcDriver";
String sC />
Connection c />
ResultSet rs=null;
public LoginBean(){
try{
Class.forName(sDBDriver);
}
catch(java.lang.ClassNotFoundException e){
System.err.println(e.getMessage());
}
}
public ResultSet executeQuery(String sql){
rs=null;
try{
c />
Statement stmt=connect.createStatement();
rs=stmt.executeQuery(sql);
}
catch(SQLException ex){
System.err.println(ex.getMessage());
}
return rs;
}
}
错误提示如下:
Apache Tomcat/4.0.6 - HTTP Status 500 - Internal Server Errortype Exception reportmessage Internal Server Errordescription The server encountered an internal error (Internal Server Error) that prevented it from fulfilling this request.exception java.lang.NullPointerException
at org.apache.jsp.login$jsp._jspService(login$jsp.java:106)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:107)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:201)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:381)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:473)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:243)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:190)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.valves.CertificatesValve.invoke(CertificatesValve.java:246)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2347)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:170)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:170)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.connector.http.HttpProcessor.process(HttpProcessor.java:1027)
at org.apache.catalina.connector.http.HttpProcessor.run(HttpProcessor.java:1125)
at java.lang.Thread.run(Thread.java:536)
以上介绍了“ 这个简单的问题为什么我搞不定?”的问题解答,希望对有需要的网友有所帮助。
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