JSP页面加载时自动执行action

[wenwensuper]

我想在JSP页面加载时自动执行action，把数据库中的新闻列表加载出来。我用了ready()函数，form_all_news是form id，代码如下：
<script>

$(document).ready(function(){
$("#form_all_news").submit();
})

</script>

…………

<form action="Search_all_news" methed="post"name="form1" id="form_all_news">
<table class="tablelist" width="700" border="1" align="center" style="position:absolute; left:360px; top:300px; background:">
<thead>
<tr>
<th>编号</th>
<th>标题</th>
<th>内容</th>
<th>发布时间</th>
</tr>
<%
ResultSet rs=(ResultSet)session.getAttribute("allnews");
try
{
while(rs.next())
{
out.println("<tr>");
out.println("<td><input name='' type='checkbox' value='' checked='checked'/></td>");
out.println("<td>");
out.println(rs.getString(1));
out.println("</td>");
out.println("<td>");
out.println(rs.getString(2));
out.println("</td>");
out.println("<td>");
out.println(rs.getString(3));
out.println("</td>");
out.println("<td>");
out.println(rs.getString(4));
out.println("</td>");
out.println("</tr>");
}
}
catch(Exception e)
{
e.printStackTrace();
}
%>
</thead>
</table>
</form>

每次进入到这个页面就会报错：

java.lang.NullPointerException
at org.apache.jsp.news_jsp._jspService(news_jsp.java:216)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:438)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:94)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:502)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1132)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:684)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2527)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2516)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)


求大神指点，谢谢！

[Gemini_Kanon]

空指针了，没获取到参数值~个人喜欢用ajax进页面请求数据，楼主这种写法还没用过

[游北亮]

news_jsp.java:216 看下这个页面的216行调用了什么对象，导致空指针了。