jdk1.6.0_10 + tomcat5.5.30 + MySQL Server 5.1
tomcat已配置成功
错误描述:
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.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:498)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:411)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:308)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:259)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
root cause java.lang.NullPointerException
org.apache.jsp.simpleDBAccess_jsp._jspService(simpleDBAccess_jsp.java:102)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:369)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:308)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:259)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.30 logs.
--------------------------------------------------------------------------------Apache Tomcat/5.5.30源程序:<%@page contentType="text/html;charset=gb2312" %>
<%@page language="java" import="java.sql.*" %>
<%
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
try
{
//载入MySQL的JDBC驱动类
Class.forName("com.mysql.jdbc.Driver");
//获得数据库连接
String sConn = "jdbc:mysql://localhost/ch01?user=root&password=****";
conn = DriverManager.getConnection( sConn );
//创建Statement对象
stmt = conn.createStatement();
//执行SQL语句
String query = "select * from user_info";
rs = stmt.executeQuery( query );
%>
<html>
<head>
<title>JSP使用JDBC连接MySQL</title>
</head>
<body>
<table border=1 cellspacing=0 cellpadding=0>
<tr bgcolor=gray>
<td>FirstName</td>
<td>LastName</td>
<td>NickName</td>
</tr>
<%
//循环操作返回的数据集
while( !rs.isLast() )
{
rs.next();
%>
<tr>
<td><%=rs.getString("first_name")%></td>
<td><%=rs.getString("last_name")%></td>
<td><%=rs.getString("nick_name")%></td>
</tr>
<%
}
}
catch(Exception e)
{
System.out.println("error occured!!");
}
finally
{
//释放数据库连接
rs.close();
stmt.close();
conn.close();
}
%>
</table>
</body>
</html>-------------------------------------------
请大家多多指教,谢谢
tomcat已配置成功
错误描述:
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.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:498)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:411)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:308)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:259)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
root cause java.lang.NullPointerException
org.apache.jsp.simpleDBAccess_jsp._jspService(simpleDBAccess_jsp.java:102)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:369)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:308)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:259)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.30 logs.
--------------------------------------------------------------------------------Apache Tomcat/5.5.30源程序:<%@page contentType="text/html;charset=gb2312" %>
<%@page language="java" import="java.sql.*" %>
<%
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
try
{
//载入MySQL的JDBC驱动类
Class.forName("com.mysql.jdbc.Driver");
//获得数据库连接
String sConn = "jdbc:mysql://localhost/ch01?user=root&password=****";
conn = DriverManager.getConnection( sConn );
//创建Statement对象
stmt = conn.createStatement();
//执行SQL语句
String query = "select * from user_info";
rs = stmt.executeQuery( query );
%>
<html>
<head>
<title>JSP使用JDBC连接MySQL</title>
</head>
<body>
<table border=1 cellspacing=0 cellpadding=0>
<tr bgcolor=gray>
<td>FirstName</td>
<td>LastName</td>
<td>NickName</td>
</tr>
<%
//循环操作返回的数据集
while( !rs.isLast() )
{
rs.next();
%>
<tr>
<td><%=rs.getString("first_name")%></td>
<td><%=rs.getString("last_name")%></td>
<td><%=rs.getString("nick_name")%></td>
</tr>
<%
}
}
catch(Exception e)
{
System.out.println("error occured!!");
}
finally
{
//释放数据库连接
rs.close();
stmt.close();
conn.close();
}
%>
</table>
</body>
</html>-------------------------------------------
请大家多多指教,谢谢
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while(rs.next())//while( !rs.isLast() )换成前面的
JDBC起码 写到.JAVA里吧
org.apache.jsp.simpleDBAccess_jsp._jspService(simpleDBAccess_jsp.java:102)这个异常信息很清楚了呀,
把simpleDBAccess_jsp.java这个文件找出来,看看102行。另外,建议写JDBC连接的时候,严格按照下面这种结构来写,别觉得麻烦,相反会避免很多麻烦,你的问题有可能是因为这个原因造成的:Connection conn = DriverManager.getConnection( sConn );
try {
Statement stmt = conn.createStatement();
try {
ResultSet rs = stmt.executeQuery( query );
try {
//TODO
}finally {
rs.close();
}
}finally {
stmt.close();
}
}finally {
conn.close();
}
<td><%=rs.getString("last_name")%></td>
<td><%=rs.getString("nick_name")%></td>這樣寫的話 顺序不能错了
//循环操作返回的数据集
while( !rs.isLast() )
{
rs.next();
%>
改成<%
while(rs.next())
{
%>
这个
{
rs.next();
%>
<tr>
<td><%=rs.getString("first_name")%></td>
<td><%=rs.getString("last_name")%></td>
<td><%=rs.getString("nick_name")%></td>
</tr>
<%
}
应该写成
while( !rs.isLast() )
{
%>
<tr>
<td><%=rs.getString("first_name")%></td>
<td><%=rs.getString("last_name")%></td>
<td><%=rs.getString("nick_name")%></td>
</tr>
<% rs.next(); }
是不是这句,密码写成*,数据没法连接啊
String sConn = "jdbc:mysql://localhost/ch01?user=root&password=****";
String sConn = "jdbc:mysql://localhost:3306/test?user=root&password=";
1 开启mysql服务。
2 引入jdbc 需要的驱动包
做好前端的一些工作。
空指针异常啊