java - Java如何通过迭代器迭代XML文件？

Question

我有 XML 文件的内容。我需要通过 Java 中的 Iterator 迭代 XML 文件。我不想通过循环或其他方式进行迭代。仅通过迭代器。你能告诉我如何通过迭代器迭代 XML 文件吗？我可以读取 XML 文件(例如文本文件)还是必须通过 DOM 解析文件？

XML 文件

 <?xml version="1.0" encoding="utf-8"?>
<Rules>

<Rule id="damaged">
    <Question>Do you want to accidents car?</Question>
    <Answer>
        <Selection value="true">
            <SingleValue value="yes"/>
        </Selection>
        <Selection value="false">
            <SingleValue value="no"/>
        </Selection>
    </Answer>
</Rule>

<Rule id="family">
    <Question>Do you want to family car?</Question>
    <Answer>
        <Selection value="true">
            <MultipleValue value="yes"/>
        </Selection>
        <Selection value="false">
            <MultipleValue value="no"/>
        </Selection>
    </Answer>
</Rule>

<Rule id="money">
    <Question>Do you have 200.000 PLN for a car?</Question>
    <Answer>
        <Selection value="true">
            <SingleValue value="yes"/>
        </Selection>
        <Selection value="false">
            <SingleValue value="no"/>
        </Selection>
    </Answer>
</Rule>

<Rule id="drivingGear">
    <Question>Do you have front-wheel drive?</Question>
    <Answer>
        <Selection value="true">
            <MultipleValue value="on the front wheels"/>
        </Selection>
        <Selection value="false">
            <MultipleValue value="on the rear wheels"/>
        </Selection>
    </Answer>
</Rule>

<Rule id="gearBox">
    <Question>Do you want to automatic gearbox?</Question>
    <Answer>
        <Selection value="true">
            <SingleValue value="automatic"/>
        </Selection>
        <Selection value="false">
            <SingleValue value="manual"/>
        </Selection>
    </Answer>
</Rule>


<Rule id="comfort">
    <Question>What is more important for you?</Question>
    <Answer>
        <Selection value="true">
            <SingleValue value="comfort"/>
        </Selection>
        <Selection value="false">
            <SingleValue value="speed"/>
        </Selection>
    </Answer>
</Rule>
...
<Rule id="luxury">
    <Question>What feature is must-have for you?</Question>
    <Answer>
        <Selection value="true">
            <MultipleValue value="gps,bluetooth,dvd,automatic transmission,self-driving"/>
        </Selection>
        <Selection value="false">
            <MultipleValue value="nothing,abs,fog lights,central lock"/>
        </Selection>
    </Answer>
</Rule>

这是我写的代码..

public class Question{

private List<String> splittedXML;

public Question(){
    this.splittedXML = new ArrayList<>();
}

public List<String> getSplittedXML(){
    return this.splittedXML;
}

public Iterator<String> QuestionIterator(){
    try (BufferedReader br = new BufferedReader(new FileReader("/home/hubert/Pulpit/expert-system-hubert/Rules.xml"))) {

        String line;

        while ((line = br.readLine()) != null) {
            String[] splittedTextXMLFile = line.split("\n");


            for(String singleLine: splittedTextXMLFile){
                if(singleLine.equals("Question")){
                    splittedXML.add(singleLine.substring(singleLine.indexOf(">") + 1, singleLine.indexOf("<")));
                }
            }

        }
        Iterator<String> itr = splittedXML.iterator();

        while(itr.hasNext()){
            return itr;
        }

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}
}

Answer 1

您永远不应该尝试通过将 XML 读取为文本来处理 XML，您应该始终使用 XML 解析器。否则，您将依赖于 XML 的意外功能，这些功能将来很容易更改，例如，如果发送者决定通过关闭缩进来提高性能。

您应该通过将其解析为内存中的树结构来处理该文件:要么是旧的、笨拙的 DOM，要么是更现代的替代方案之一，例如 JDOM2 或 XOM。