高分跪求错误原因!在线等待高手
小弟 作连接数据库查询的jsp.环境为 linux+ jakart-tomcat+ Mysql 以前在win下用的是access 可以正常运行 但用mysql以后出错:如下
Error: 500
Location: /zxb/Jsp3.jsp
Internal Servlet Error:
javax.servlet.ServletException
at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:386)
at _0002fJsp_00033_0002ejspJsp3_jsp_0._jspService(_0002fJsp_00033_0002ejspJsp3_jsp_0.java:91)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:126)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.jasper.runtime.JspServlet$JspServletWrapper.service(JspServlet.java:174)
at org.apache.jasper.runtime.JspServlet.serviceJspFile(JspServlet.java:261)
at org.apache.jasper.runtime.JspServlet.service(JspServlet.java:369)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.tomcat.core.ServletWrapper.handleRequest(ServletWrapper.java:503)
at org.apache.tomcat.core.ContextManager.service(ContextManager.java:559)
at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:160)
at org.apache.tomcat.service.TcpConnectionThread.run(SimpleTcpEndpoint.java:338)
at java.lang.Thread.run(Thread.java:536)
Root cause:
java.lang.NullPointerException
at _0002fJsp_00033_0002ejspJsp3_jsp_0._jspService(_0002fJsp_00033_0002ejspJsp3_jsp_0.java:61)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:126)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.jasper.runtime.JspServlet$JspServletWrapper.service(JspServlet.java:174)
at org.apache.jasper.runtime.JspServlet.serviceJspFile(JspServlet.java:261)
at org.apache.jasper.runtime.JspServlet.service(JspServlet.java:369)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.tomcat.core.ServletWrapper.handleRequest(ServletWrapper.java:503)
at org.apache.tomcat.core.ContextManager.service(ContextManager.java:559)
at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:160)
at org.apache.tomcat.service.TcpConnectionThread.run(SimpleTcpEndpoint.java:338)
at java.lang.Thread.run(Thread.java:536)。
请教高手大概是哪方面的错误。
我觉得有可能是连接class出错(本人数据库名为zxb,-u root -proot:
ackage zxb;
import java.sql.*;
public class conn {
String sDBDriver = "org.gjt.mm.mysql.Driver";
String sConnStr = "jdbc:mysql://localhost/zxb?user=root&root=root";
Connection connect = null;
ResultSet rs = null;
public conn() {
try {
Class.forName(sDBDriver);
}
catch(java.lang.ClassNotFoundException e) {
System.err.println( e.getMessage());
}
}
public ResultSet executeQuery(String sql) {
rs = null;
try {
connect = DriverManager.getConnection(sConnStr);
Statement stmt = connect.createStatement();
rs = stmt.executeQuery(sql);
}
catch(SQLException ex) {
System.err.println(ex.getMessage());
}
等待大家的帮助!