Question

jsp中Class.forName(driverClass)出错

关键代码是
String user = request.getParameter("username");
String pass = request.getParameter("password");

String driverClass = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
String url = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=JSP";
String username = "sa";
String password = "";
Class.forName(driverClass);
Connection conn = DriverManager.getConnection(url, username,
password);
Statement stmt = conn.createStatement();

String sql = "select * from tb_users where username='" + user
+ "' and userpwd='" + pass + "'";
ResultSet rs = stmt.executeQuery(sql);
if (rs.next()) {
rs.close();
stmt.close();
conn.close();
out.print("登陆成功！");
response.sendRedirect("show.jsp");
} else {
out.print("登陆错误！");
response.sendRedirect("login.jsp");
}
错误是
org.apache.jasper.JasperException: An exception occurred processing JSP page /dologin.jsp at line 25

22: String url = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=JSP";
23: String username = "sa";
24: String password = "";
25: Class.forName(driverClass);
26: Connection conn = DriverManager.getConnection(url, username,
27: password);
28: Statement stmt = conn.createStatement();

Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:524)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:417)
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)

Answer 1

是不是你没有放好JDBC驱动jar包？

这个异常信息不明朗，你可以用try catch把出问题的那段代码包起来，然后打印输出异常信息，就可以在控制台看到具体的异常信息了。

Answer 2

项目加驱动包了没？

追问

加了的，一直说Class.forName(driverClass);
这句有错，不知道为什么

追答

很少把数据库连接直接写在JSP里面，耦合太深了。写在java文件里面是需要引用“java.sql.*”，你前面引用了吗？还有就是一般数据库连接都要用try {}catch（）{}括起来。