JAVA高级面试进阶训练营视频教程

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转载自：http://blog.csdn.net/dracotianlong/article/details/47604723

Spring接受前台的数据超过256出现如下异常：

org.springframework.beans.InvalidPropertyException: Invalid property 'specificationValues[256]' of bean class [com.sencloud.entity.Specification]: Index of out of bounds in property path 'specificationValues[256]'; nested exception is java.lang.IndexOutOfBoundsException: Index: 256, Size: 256
    org.springframework.beans.BeanWrapperImpl.getPropertyValue(BeanWrapperImpl.java:811)
    org.springframework.beans.BeanWrapperImpl.getNestedBeanWrapper(BeanWrapperImpl.java:554)

溯源了下Spring的代码，找到了DataBinder，先解释下DataBinder类的作用，见链接

http://docs.spring.io/spring/docs/1.2.x/api/org/springframework/validation/DataBinder.html

其中有一句

Binder that allows for binding property values to a target object. The binding process can be customized through specifying allowed fields, required fields, and custom editors.
Note that there are potential security implications in failing to set an array of allowed fields. In the case of HTTP form POST data for example, malicious clients can attempt to subvert an application by supplying values for fields or properties that do not exist on the form. In some cases this could lead to illegal data being set on command objects or their nested objects. For this reason, it is highly recommended to specify the allowedFields property on the DataBinder.

 

大概意思是前台的Form 元素绑定到 后台的JaveBean对象，做的一个映射，但是这个映射的List长度不可以超过256

反编译的源码如下：

 

 

解决如下：重set下autoGrowCollectionLimit，当做绑定的时候set为1024或者更大

/**
     * 数据绑定
     * 
     * @param binder
     *            WebDataBinder
     */
    @InitBinder
    protected void initBinder(WebDataBinder binder) {
        binder.setAutoGrowCollectionLimit(2048);  
        
    }