简单问题，帮帮初学者，谢谢了。

空指针异常，肯定是数据没对上，个数，名字在jsp和serlvet,javabean中要前后一致

你在JSP里调用的一个方法返回来的类是NULL
而你却没有判断是不是NULL
直接用了该类的方法或属性

registry.html文件：
<HTML>
<HEAD>
<TITLE>registry</TITLE>
</HEAD>
<BODY>
<FORM METHOD=POST ACTION="http://localhost:8080/firstjsp/registry.jsp">
姓名：<input name="name" type="text">
<input type="submit" value="提交">
</form>
</FORM>
</BODY>
</HTML>registry.jsp文件：
<%@ page import="java.sql.*"%>
<html>
<head>
<title>registry.jsp
</title>
</head>
<body>
<%
   Connection c = null;
   Statement s = null;
   ResultSet rs = null;
   String name = request.getParameter("name");
   try {
   Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
   String url = "jdbc:microsoft:sqlserver://localhost:1433;database=student";
   c = DriverManager.getConnection(url,"xy","12345678");
   s = c.createStatement();
   String upd = "insert into test (name) values("+name+")";
   s.executeUpdate(upd);
   s.close();
   c.close();
   }
   catch(SQLException e) {
   System.out.println(e);
   }
%>
</body>
</html>错误如下：
type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception javax.servlet.ServletException: com.microsoft.jdbc.sqlserver.SQLServerDriver
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:682)
org.apache.jsp.registry_jsp._jspService(registry_jsp.java:75)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:136)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:320)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:294)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
tw.com.javaworld.CH11.HelloFilter.doFilter(Unknown Source)
root cause java.lang.ClassNotFoundException: com.microsoft.jdbc.sqlserver.SQLServerDriver
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1378)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1225)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:188)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:114)
java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)
java.lang.Class.forName0(Native Method)
java.lang.Class.forName(Class.java:141)
org.apache.jsp.registry_jsp._jspService(registry_jsp.java:54)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:136)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:320)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:294)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
tw.com.javaworld.CH11.HelloFilter.doFilter(Unknown Source)
note The full stack trace of the root cause is available in the Tomcat logs.谢谢大家帮我改改。

String name = request.getParameter("name");
if(name!=null) {
  try{
    ...
  }catch(Exception e) {
  }
}

我在classpath里加了E:\Program Files\Microsoft SQL Server 2000 driver for JDBC\lib\msbase.jar;E:\Program Files\Microsoft SQL Server 2000 driver for JDBC\lib\mssqlserver.jar;E:\Program Files\Microsoft SQL Server 2000 driver for JDBC\lib\msutil.jar
但是还是报错

重启机器，最好把驱动放在WEB－INF\lib 下面，也不用修改classpath

如果在数据库中name是String型的话，
String upd = "insert into test (name) values("+name+")";>>String upd = "insert into test (name) values('"+name+"')";
而且如果是非空，在提取的时候一定要判断，做特殊处理。

谢谢大家那个问题解决了，现在又出另外的个错，错误如下：
type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: /registry.jsp(10,0) According to TLD, tag jsp:setProperty must be empty, but is not
org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:83)
org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:363)
org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:167)
org.apache.jasper.compiler.Parser.parseBody(Parser.java:1757)
org.apache.jasper.compiler.Parser.parseOptionalBody(Parser.java:1096)
org.apache.jasper.compiler.Parser.parseSetProperty(Parser.java:994)
org.apache.jasper.compiler.Parser.parseStandardAction(Parser.java:1265)
org.apache.jasper.compiler.Parser.parseElements(Parser.java:1589)
org.apache.jasper.compiler.Parser.parse(Parser.java:172)
org.apache.jasper.compiler.ParserController.parse(ParserController.java:252)
org.apache.jasper.compiler.ParserController.parse(ParserController.java:152)
org.apache.jasper.compiler.ParserController.parse(ParserController.java:138)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:246)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:454)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:440)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:555)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:300)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:294)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
tw.com.javaworld.CH11.HelloFilter.doFilter(Unknown Source)
note The full stack trace of the root cause is available in the Tomcat logs.

看看这个提示jsp:setProperty must be empty, but is not

String name = request.getParameter("name");
把这个值打印出来看看。是不是空。
是不是没有得到这个值？

String upd = "insert into test (name) values('"+name+"')";这样看看

调试易

简单问题，帮帮初学者，谢谢了。

解决方案 »