系统空指针异常，tomcat报内存溢出

早上在管理后台操作，在打开流程的时候报错：
Caused by: javax.servlet.ServletException: java.lang.OutOfMemoryError: Java heap space
        at org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:862)
        at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:791)
        at org.apache.jsp.portal.default_.dynaform.document.content_jsp._jspService(content_jsp.java:1706)
        at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
        ... 53 more
另外在保存表单的时候也报错：
10:45:57,734 ERROR DispatcherUtils:245 - Could not execute action
java.lang.NullPointerException
        at cn.myapps.core.dynaform.activity.action.ActivityAction.doAction(ActivityAction.java:316)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at com.opensymphony.xwork.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:365)
        at com.opensymphony.xwork.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:217)
        at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:191)
        at com.opensymphony.xwork.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:137)
        at com.opensymphony.xwork.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:81)
        at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:189)
        at com.opensymphony.xwork.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:115)
        at com.opensymphony.xwork.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:81)
        at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:189)
        at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:31)
        at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:189)
        at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:31)
        at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:189)
        at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:31)
        at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:189)
        at com.opensymphony.webwork.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:171)
        at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:189)
        at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:31)
        at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:189)
        at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:31)
        at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:189)
        at com.opensymphony.xwork.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:151)
        at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:189)
        at com.opensymphony.xwork.DefaultActionProxy.execute(DefaultActionProxy.java:113)
        at com.opensymphony.webwork.dispatcher.DispatcherUtils.serviceAction(DispatcherUtils.java:233)
        at com.opensymphony.webwork.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:198)
        at cn.myapps.base.web.filter.OBPMFilterDispatcher.doFilter(OBPMFilterDispatcher.java:39)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at com.opensymphony.webwork.dispatcher.ActionContextCleanUp.doFilter(ActionContextCleanUp.java:78)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at cn.myapps.base.web.filter.PersistenceFilter.doFilter(PersistenceFilter.java:30)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at cn.myapps.base.web.filter.SecurityFilter.doFilter(SecurityFilter.java:175)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:263)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:584)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
        at java.lang.Thread.run(Thread.java:619)
10:45:57,734 ERROR OBPMFilterDispatcher:44 - URL: /core/dynaform/activity/action.action
javax.servlet.ServletException: Could not execute action
        at com.opensymphony.webwork.dispatcher.DispatcherUtils.serviceAction(DispatcherUtils.java:246)
        at com.opensymphony.webwork.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:198)
        at cn.myapps.base.web.filter.OBPMFilterDispatcher.doFilter(OBPMFilterDispatcher.java:39)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at com.opensymphony.webwork.dispatcher.ActionContextCleanUp.doFilter(ActionContextCleanUp.java:78)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at cn.myapps.base.web.filter.PersistenceFilter.doFilter(PersistenceFilter.java:30)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at cn.myapps.base.web.filter.SecurityFilter.doFilter(SecurityFilter.java:175)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
        at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NullPointerException
        at cn.myapps.core.dynaform.activity.action.ActivityAction.doAction(ActivityAction.java:316)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at com.opensymphony.xwork.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:365)
        at com.opensymphony.xwork.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:217)
        at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:191)
        at com.opensymphony.xwork.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:137)
        at com.opensymphony.xwork.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:81)
        at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:189)
        at com.opensymphony.xwork.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:115)
        at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:189)
        at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:31)
        at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:189)
        at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:31)
        at com.opensymphony.webwork.dispatcher.DispatcherUtils.serviceAction(DispatcherUtils.java:233)
        ... 23 more

发表内容有限，基本上异常信息就上面这些。
注：在生产环境下，tomcat经常会报空指针异常，然后过几天就服务挂掉，一直找不到什么原因。客户急着给解决方案。

由于这几天公司搬家，你发给我那代码我们会去测完的！