JSP程序之前一台电脑可以运行，但是另一台电脑就不行

程序如下

 5.public class DBConBean {

    private static final String URL = "jdbc:mysql://127.0.0.1:3306/bank";
    private static final String USER = "root";
    private static final String PASSWORD = "";

    private static Connection conn = null;
    Statement stat = null;
    PreparedStatement pstat = null;
    ResultSet rs = null;
    int rs_1 = 0;

    public static Connection getConnection() {
        try {
            //加载驱动程序
            Class.forName("com.mysql.jdbc.Driver");
            //获得数据库连接
            conn = DriverManager.getConnection(URL, USER, PASSWORD);
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return conn;
    }

    public ResultSet query (String sql) {
        try {
            conn = getConnection();
37.         stat = conn.createStatement();
            rs = stat.executeQuery(sql);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return rs;
    }

报错如下
type Exception report

message java.lang.NullPointerException

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: java.lang.NullPointerException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:556)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:477)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause

java.lang.NullPointerException
com.zy.dao.DBConBean.query(DBConBean.java:37)
org.apache.jsp.Page_005fuser_jsp._jspService(Page_005fuser_jsp.java:161)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.65 logs.
求大神解答

断点一下看看conn是不是为空，如果为空就可以往2个方向找错误，1，有没有jdbc的驱动包，2、用户名密码和URL是不是对，你这里可以在本地用数据库的客户端看看能不能脸上，有没有这个数据库。

另一台电脑的数据库账户密码和URL填对了么？

jdbc驱动的jar包、mysql的配置，无非这两个原因。
目测下，很可能是Class.forName("com.mysql.jdbc.Driver");这里没有加载导致null

你是不是导包倒错了？检查下

这种问题还是在报错的机器程序上打断点监控一下吧。空指针异常断点比什么都来的快。

具体原因可在：http://www.everycoding.com/question/146.html 获得解决。

谢谢各位大神，错误已经发现了，因为jdbc的包没有放到tomcat的lib下面，所以导致了错误