# LinkedHashMap 插入内容时候的出现 null 对象错误

**URL:** <https://www.isharkfly.com/t/linkedhashmap-null/7016>\
**Category:** 程序语言\
**Tags:** java\
**Created:** [June 12, 2013, 8:52pm UTC](https://www.isharkfly.com/t/linkedhashmap-null/7016 "2013-06-12T20:52:19Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![honeymoose](https://www.isharkfly.com/user_avatar/www.isharkfly.com/honeymoose/32/20796_2.png) [@honeymoose](https://www.isharkfly.com/u/honeymoose)\
**Post date:** [June 12, 2013, 8:52pm UTC](https://www.isharkfly.com/t/linkedhashmap-null/7016/1 "2013-06-12T20:52:19Z")

</div>

程序错误内容如下：

```auto
2013-06-12 16:42:43,805 [32922362@qtp0-6] ERROR errors.GrailsExceptionResolver - java.lang.NullPointerException: Cannot invoke method put() on null object
org.codehaus.groovy.runtime.InvokerInvocationException: java.lang.NullPointerException: Cannot invoke method put() on null object
	at com.verani.common.web.servlets.SavedSearchFilter.doFilter(SavedSearchFilter.java:93)
	at com.verani.common.cms.servlets.PageFilter.doFilter(PageFilter.java:168)
	at com.verani.common.web.servlets.SavedSearchFilter.doFilter(SavedSearchFilter.java:57)
	at com.verani.common.cms.servlets.PageFilter.doFilter(PageFilter.java:168)
	at com.verani.common.web.servlets.OpenSessionInViewFilter.doFilter(OpenSessionInViewFilter.java:38)
Caused by: java.lang.NullPointerException: Cannot invoke method put() on null object
	at com.verani.web.platform.controllers.ViperListingController$_closure21.doCall(com.verani.web.platform.controllers.ViperListingController:3081)
	at com.verani.web.platform.controllers.ViperListingController$_closure21.doCall(com.verani.web.platform.controllers.ViperListingController)
	... 5 more

```

这是因为程序定义：` LinkedHashMap<String, String> basicDetails` 如果这时候尝试向 LinkedHashMap put 数据，将会得到上面的错误。

可以将变量初始化为：`LinkedHashMap<String, String> basicDetails = new LinkedHashMap<String, String>();`就没有这个错误了。