从 XML 文件中删除节点 java 程序
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/11411604/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
remove node from XML file java program
提问by mallikarjun
When I try to remove a node from XML node from java program it is giving me a strange problem. It is removing alternate nodes. I have to remove existing nodes before inserting new nodes. my xml file is:
当我尝试从 Java 程序的 XML 节点中删除一个节点时，它给了我一个奇怪的问题。它正在删除备用节点。在插入新节点之前，我必须删除现有节点。我的 xml 文件是：
<?xml version="1.0" encoding="windows-1252" ?>
<chart>
<categories>
<category label="3 seconds"/>
<category label="6 seconds"/>
<category label="9 seconds"/>
<category label="12 seconds"/>
</categories>
</chart>
my java program is:
我的java程序是：
DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
Document doc = docBuilder.parse(filePath);
Node categories = doc.getElementsByTagName("categories").item(0);
NodeList categorieslist = categories.getChildNodes();
// if exists delete old data the insert new data.
for (int c = 0; c < categorieslist.getLength(); c++) {
Node node = categorieslist.item(c);
categories.removeChild(node);
}
for(int i=1;i<20;i++){
Element category = doc.createElement("category");
category.setAttribute("label",3*i+" seconds");
categories.appendChild(category);
}
This code is deleting alternative nodes I don't know why. The resulting XML is showing like this:
此代码正在删除替代节点，我不知道为什么。生成的 XML 显示如下：
<categories>
<category label="6 seconds"/>
<category label="12 seconds"/>
<category label="3 seconds"/>
<category label="6 seconds"/>
<category label="9 seconds"/>
.....
.....
</categories>
回答by Anton
Every time you remove a child the list becomes shorter, the list isn't a static collections, so every time you call getLength() you get the actual size
每次删除孩子时，列表都会变短，列表不是静态集合，因此每次调用 getLength() 时都会得到实际大小
Node categories = doc.getElementsByTagName("categories").item(0);
NodeList categorieslist = categories.getChildNodes();
while (categorieslist.getLength() > 0) {
Node node = categorieslist.item(0);
node.getParentNode().removeChild(node);
}
