在SpringMVC界面删除数据库表中字段的时候，出现报错如下：
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.orm.hibernate3.HibernateSystemException:Null value was assigned to a property of primitive type setter of com.xxx.CurrentData.accountAccumulateFlow; nested exception is org.hibernate.PropertyAccessException: Null value was assigned to a property of primitive type setter of com.xxx.CurrentData.accountAccumulateFlow
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:948)at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:827)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at com.xxx.web.filter.LoginFilter.doFilter(LoginFilter.java:65)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:118)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:84)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at com.xxx.security.SecurityInterceptorFilter.invoke(SecurityInterceptorFilter.java:52)
at com.xxx.security.SecurityInterceptorFilter.doFilter(SecurityInterceptorFilter.java:45)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:103)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:146)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:150)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
解决方案：把实体类中的原始类型全部转化为包装类型
Java语言是一个面向对象的语言，但是Java中的基本数据类型却是不面向对象的，这在实际使用时存在很多的不便，为了解决这个不足，在设计类时为每个基本数据类型设计了一个对应的类进行代表，这样八个和基本数据类型对应的类统称为包装类(Wrapper Class)，有些地方也翻译为外覆类或数据类型类。
包装类均位于java.lang包，包装类和基本数据类型的对应关系如下表所示：
包装类对应表
|
基本数据类型 |
包装类 |
|
byte |
Byte |
|
boolean |
Boolean |
|
short |
Short |
|
char |
Character |
|
int |
Integer |
|
long |
Long |
|
float |
Float |
|
double |
Double |
在这八个类名中，除了Integer和Character类以后，其它六个类的类名和基本数据类型一直，只是类名的第一个字母大写即可。
对于包装类说，这些类的用途主要包含两种：
a、作为和基本数据类型对应的类类型存在，方便涉及到对象的操作。
b、包含每种基本数据类型的相关属性如最大值、最小值等，以及相关的操作方法。
