在SpringMVC界面刪除數據庫表中字段的時候，出現報錯如下：
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)
解決方案：把實體類中的原始類型全部轉化爲包裝類型
Java語言是一個面向對象的語言，但是Java中的基本數據類型卻是不面向對象的，這在實際使用時存在很多的不便，爲了解決這個不足，在設計類時爲每個基本數據類型設計了一個對應的類進行代表，這樣八個和基本數據類型對應的類統稱爲包裝類(Wrapper Class)，有些地方也翻譯爲外覆類或數據類型類。
包裝類均位於java.lang包，包裝類和基本數據類型的對應關係如下表所示：
包裝類對應表
|
基本數據類型 |
包裝類 |
|
byte |
Byte |
|
boolean |
Boolean |
|
short |
Short |
|
char |
Character |
|
int |
Integer |
|
long |
Long |
|
float |
Float |
|
double |
Double |
在這八個類名中，除了Integer和Character類以後，其它六個類的類名和基本數據類型一直，只是類名的第一個字母大寫即可。
對於包裝類說，這些類的用途主要包含兩種：
a、作爲和基本數據類型對應的類類型存在，方便涉及到對象的操作。
b、包含每種基本數據類型的相關屬性如最大值、最小值等，以及相關的操作方法。
