Action Exception: null

java.lang.NullPointerException at com.shangsou.shangpu.web.action.OpportunityAction.listSellCol(Unknown Source) at sun.reflect.GeneratedMethodAccessor62.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at com.shangsou.shangpu.web.action.DispatchAction.dispatchMethod(Unknown Source) at com.shangsou.shangpu.web.action.DispatchAction.execute(Unknown Source) at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:419) at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:224) at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194) at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414) at javax.servlet.http.HttpServlet.service(HttpServlet.java:115) at javax.servlet.http.HttpServlet.service(HttpServlet.java:92) at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:106) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:277) at com.caucho.server.webapp.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:106) at com.caucho.filters.RewriteFilter.doFilter(RewriteFilter.java:111) at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:70) at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:173) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:274) at com.caucho.server.port.TcpConnection.run(TcpConnection.java:511) at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:520) at com.caucho.util.ThreadPool.run(ThreadPool.java:442) at java.lang.Thread.run(Thread.java:595)