各位高手好，麻烦帮我看下这个数据库连接问题：
做了一个BBS但是数据库就是连接不上。错误代码如下
HTTP Status 500 -
--------------------------------------------------------------------------------
type Exception report
message
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:522)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:416)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause
java.lang.NullPointerException
org.apache.jsp.pass_jsp._jspService(pass_jsp.java:79)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
我现在用struts2框架,需要使用ajax实现局部刷新，但是从容器里返回的值不知道怎么从struts.xml配置文件里映射到jsp页面里，以前servlet里写out.orint("xxxxx")就可以得到~，但是现在用struts就不知道怎么� ......
private static final String URL = "jdbc:oracle:thin:@localhost:1521:orcl";
private static final String USERNAME = "sys";
private static final String PASSWORD = "s ......
