java.lang.NullPointerException-net.sf.json.JSONObject.defaultBeanProcessing(JSONObject.java:749)

转换json时，遇到以下这样的问题，问题引发的主要原因是属性申明时，使用的是Long包装类型，但是set，get方法使用的是long普通数据类型。导致在转换json数据时，就报错了。
解决办法：将set，get方法修改为Long包装类型

java.lang.NullPointerException    at com.newsoft.transactioncheckcommon.po.Laneexlist.getImageserialno(Laneexlist.java:508)    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 org.apache.commons.beanutils.PropertyUtilsBean.invokeMethod(PropertyUtilsBean.java:2170)    at org.apache.commons.beanutils.PropertyUtilsBean.getSimpleProperty(PropertyUtilsBean.java:1332)    at org.apache.commons.beanutils.PropertyUtilsBean.getNestedProperty(PropertyUtilsBean.java:770)    at org.apache.commons.beanutils.PropertyUtilsBean.getProperty(PropertyUtilsBean.java:846)    at org.apache.commons.beanutils.PropertyUtils.getProperty(PropertyUtils.java:426)    at net.sf.json.JSONObject.defaultBeanProcessing(JSONObject.java:749)    at net.sf.json.JSONObject._fromBean(JSONObject.java:699)    at net.sf.json.JSONObject.fromObject(JSONObject.java:172)    at net.sf.json.AbstractJSON._processValue(AbstractJSON.java:274)    at net.sf.json.JSONArray._processValue(JSONArray.java:2513)    at net.sf.json.JSONArray.processValue(JSONArray.java:2538)    at net.sf.json.JSONArray.addValue(JSONArray.java:2525)    at net.sf.json.JSONArray._fromCollection(JSONArray.java:1056)    at net.sf.json.JSONArray.fromObject(JSONArray.java:123)    at net.sf.json.AbstractJSON._processValue(AbstractJSON.java:240)    at net.sf.json.JSONObject._processValue(JSONObject.java:2655)    at net.sf.json.JSONObject.processValue(JSONObject.java:2721)    at net.sf.json.JSONObject.setInternal(JSONObject.java:2736)    at net.sf.json.JSONObject.setValue(JSONObject.java:1424)    at net.sf.json.JSONObject._fromMap(JSONObject.java:1168)    at net.sf.json.JSONObject.fromObject(JSONObject.java:163)    at net.sf.json.JSONObject.fromObject(JSONObject.java:134)    at com.newsoft.utils.JSONTool.toJson(JSONTool.java:65)    at com.newsoft.watch.controller.ServiceMonitorController.getAllStationTransList(ServiceMonitorController.java:579)    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 org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176)    at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:436)    at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:424)    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790)    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:669)    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:585)    at javax.servlet.http.HttpServlet.service(HttpServlet.java:643)    at javax.servlet.http.HttpServlet.service(HttpServlet.java:723)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:369)    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:109)    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:83)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)    at com.newsoft.security.NSFilterSecurityInterceptor.invoke(NSFilterSecurityInterceptor.java:51)    at com.newsoft.security.NSFilterSecurityInterceptor.doFilter(NSFilterSecurityInterceptor.java:36)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)    at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:97)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)    at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:100)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)    at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:78)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)    at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)    at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:35)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)    at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:177)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)    at org.springframework.security.web.authentication.ui.DefaultLoginPageGeneratingFilter.doFilter(DefaultLoginPageGeneratingFilter.java:91)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)    at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:187)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)    at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:187)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)    at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)    at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)    at org.springframework.security.web.session.ConcurrentSessionFilter.doFilter(ConcurrentSessionFilter.java:109)    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:168)    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)    at org.apache.catalina.core.StandardContextValve.__invoke(StandardContextValve.java:191)    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java)    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)    at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:879)    at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:610)    at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1777)    at java.lang.Thread.run(Thread.java:662)