从java中的XML文件中删除元素 [英] remove elements from XML file in java

问题描述

我已经从excel数据库生成了一个xml文件，它自动包含一个名为 offset 的元素。为了使我的新文件符合我的需要，我想使用java删除这个元素。
这里是xml内容：

I have generated an xml file from an excel data base and it contains automatically an element called "offset". To make my new file match my needs, I want to remove this element using java. here is the xml content:

<Root><models><id>2</id><modelName>Baseline</modelName><domain_id>2</domain_id><description> desctiption </description><years><Y2013>value1</Y2013><Y2014>value2</Y2014><Y2015>value3</Y2015><Y2016>value4</Y2016><Y2017>value5</Y2017></years><offset/></models></Root>

我创建了一个代码（使用缓冲读取器）并将内容写入新文件中使用条件if：

I made a code that reads(with a buffered reader) and writes the content in a new file and used the condition if:

        while (fileContent !=null){
        fileContent=xmlReader.readLine();
        if (!(fileContent.equals("<offset/>"))){
            System.out.println("here is the line:"+ fileContent);
            XMLFile+=fileContent;
            }


    }

但确实如此不工作

推荐答案

我个人建议使用适当的XML解析器，如Java DOM 检查和删除节点，而不是将XML作为原始XML处理 String s（哎呀）。尝试这样的方法来删除你的'偏移'节点。

I would personally recommend using a proper XML parser like Java DOM to check and delete your nodes, rather than dealing with your XML as raw Strings (yuck). Try something like this to remove your 'offset' node.

File xmlFile = new File("your_xml.xml");
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(xmlFile);

NodeList nList = doc.getElementsByTagName("offset");
for (int i = 0; i < nList.getLength(); i++) {
    Node node = nList.item(i);
    node.getParentNode().removeChild(node); 
}

上面的代码删除了xml文件中的所有偏移节点。

The above code removes any 'offset' nodes in an xml file.

如果资源/速度考虑是一个问题（例如当your_xml.xml很大时），那么最好使用 SAX ，它更快（代码密集程度更高）并且不会将XML存储在内存中。

If resources/speed considerations are an issue (like when your_xml.xml is huge), you would be better off using SAX, which is faster (a little more code intensive) and doesn't store the XML in memory.

一旦你的文件被编辑了，你可能想要将其转换为字符串以解析为您选择的 OutputStream 。

Once your Document has been edited you'll probably want to convert it to a String to parse to your OutputStream of choice.

希望这会有所帮助。

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