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什么叫XML中的延迟节点扩展？

[英]What is called defer-node-expansion in XML?

原文 2009-12-03 14:07:54 1 2 java/ xml/ apache/ parsing

What this feature " http://apache.org/xml/features/dom/defer-node-expansion " does? 这个功能“ http://apache.org/xml/features/dom/defer-node-expansion ”有什么作用？

i have read about this feature . 我已阅读有关此功能的信息。 But was really unable to understand what will happen if this is set to false. 但实际上无法理解如果将其设置为false将会发生什么。

Can anyone come up elaborately on this as i don't find any other link that explain to the ability i understand. 任何人都可以精心制作这个，因为我没有找到任何其他链接解释我理解的能力。

2 个解决方案

by deferred node expansion, basically, a lot of objects/strings are not created/allocated until you navigate to the corresponding node position... it makes dom parsing a bit faster but tree traversal slower ... 通过延迟节点扩展，基本上，在导航到相应的节点位置之前，不会创建/分配大量对象/字符串...它使得dom解析速度更快但树遍历更慢...

the initial memory consumption is lower than a full-expanded DOM tree, but after traversal, the memory usage could easily be a lot higher than a full-expanded DOM tree... beware of the catch 初始内存消耗低于完全扩展的DOM树，但在遍历之后，内存使用量可能比完全扩展的DOM树要高很多...谨防捕获

it is a form lazy loading : DOM nodes are created as you traverse tree. 它是一种延迟加载形式：在遍历树时创建DOM节点。

This is a common design pattern, it is widely used. 这是一种常见的设计模式，因此被广泛使用。 For example Hibernate calls it Lazy Fetching . 例如，Hibernate将其称为Lazy Fetching 。