formBackingObject 返回后就报错...

org.springframework.beans.InvalidPropertyException: Invalid property 'prices[1]' of bean class [com.liantuo.apps.manage.vo.PreOrderForm]: Index of out of bounds in property path 'prices[1]'; nested exception is java.lang.IndexOutOfBoundsException: Index: 1, Size: 1;
org.springframework.beans.BeanWrapperImpl.getPropertyValue(BeanWrapperImpl.java:613);<br>
org.springframework.beans.BeanWrapperImpl.getNestedBeanWrapper(BeanWrapperImpl.java:447);<br>
org.springframework.beans.BeanWrapperImpl.getBeanWrapperForPropertyPath(BeanWrapperImpl.java:424);<br>
org.springframework.beans.BeanWrapperImpl.setPropertyValue(BeanWrapperImpl.java:641);<br>
org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:78);<br>
org.springframework.validation.DataBinder.applyPropertyValues(DataBinder.java:587);<br>
org.springframework.validation.DataBinder.doBind(DataBinder.java:489);<br>
org.springframework.web.bind.WebDataBinder.doBind(WebDataBinder.java:149);<br>
org.springframework.web.bind.ServletRequestDataBinder.bind(ServletRequestDataBinder.java:110);<br>
org.springframework.web.servlet.mvc.BaseCommandController.bindAndValidate(BaseCommandController.java:391);<br>
org.springframework.web.servlet.mvc.AbstractFormController.handleRequestInternal(AbstractFormController.java:263);<br>
org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:153);<br>
org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:48);<br>
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:875);<br>
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:807);<br>
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:571);<br>
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:511);<br>
javax.servlet.http.HttpServlet.service(HttpServlet.java:647);<br>
javax.servlet.http.HttpServlet.service(HttpServlet.java:729);<br>
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269);<br>
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188);<br>
org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198);<br>
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76);<br>
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215);<br>
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188);<br>
com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:119);<br>
com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:55);<br>
com.liantuo.common.sitemesh.filter.VelocityPageFilter.doFilter(VelocityPageFilter.java:32);<br>
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215);<br>
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188);<br>
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96);<br>
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76);<br>
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215);<br>
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188);<br>
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213);<br>
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172);<br>
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127);<br>
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117);<br>
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108);<br>
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174);<br>
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:875);<br>
org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665);<br>
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528);<br>
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81);<br>
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689);<br>
java.lang.Thread.run(Thread.java:619);<br>
<br><br>
java.lang.IndexOutOfBoundsException: Index: 1, Size: 1;
java.util.ArrayList.RangeCheck(ArrayList.java:547);<br>
java.util.ArrayList.get(ArrayList.java:322);<br>
org.springframework.beans.BeanWrapperImpl.getPropertyValue(BeanWrapperImpl.java:562);<br>
org.springframework.beans.BeanWrapperImpl.getNestedBeanWrapper(BeanWrapperImpl.java:447);<br>
org.springframework.beans.BeanWrapperImpl.getBeanWrapperForPropertyPath(BeanWrapperImpl.java:424);<br>
org.springframework.beans.BeanWrapperImpl.setPropertyValue(BeanWrapperImpl.java:641);<br>
org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:78);<br>
org.springframework.validation.DataBinder.applyPropertyValues(DataBinder.java:587);<br>
org.springframework.validation.DataBinder.doBind(DataBinder.java:489);<br>
org.springframework.web.bind.WebDataBinder.doBind(WebDataBinder.java:149);<br>
org.springframework.web.bind.ServletRequestDataBinder.bind(ServletRequestDataBinder.java:110);<br>
org.springframework.web.servlet.mvc.BaseCommandController.bindAndValidate(BaseCommandController.java:391);<br>
org.springframework.web.servlet.mvc.AbstractFormController.handleRequestInternal(AbstractFormController.java:263);<br>
org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:153);<br>
org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:48);<br>
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:875);<br>
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:807);<br>
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:571);<br>
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:511);<br>
javax.servlet.http.HttpServlet.service(HttpServlet.java:647);<br>
javax.servlet.http.HttpServlet.service(HttpServlet.java:729);<br>
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269);<br>
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188);<br>
org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198);<br>
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76);<br>
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215);<br>
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188);<br>
com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:119);<br>
com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:55);<br>
com.liantuo.common.sitemesh.filter.VelocityPageFilter.doFilter(VelocityPageFilter.java:32);<br>
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215);<br>
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188);<br>
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96);<br>
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76);<br>
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215);<br>
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188);<br>
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213);<br>
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172);<br>
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127);<br>
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117);<br>
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108);<br>
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174);<br>
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:875);<br>
org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665);<br>
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528);<br>
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81);<br>
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689);<br>
java.lang.Thread.run(Thread.java:619);<br>