java - 如何使用DOM解析器在java中解析具有相同标签名称的嵌套XML？

Question

I have to put the values of "s" and "r" tags in map of arraylist. So, I want to get their values. I am confused about how to get the values of nested identical tags. Can someone help me to do that? Thanks in advance!

Demo.xml file

<?xml version="1.0"?>

<Record>
    <app_name>app1</app_name>
    <faults>
        <Record>
            <s>1 </s>
            <r>Fixed </r>
        </Record>
        <Record>
            <s>2 </s>
            <r>New </r>
        </Record>
        <Record>
            <s>1 </s>
            <r>Fixed </r>
        </Record>
    </faults>
</Record>

<Record>
    <app_name>app2</app_name>
    <faults>
        <Record>
            <s>0 </s>
            <r>New </r>
        </Record>
        <Record>
            <s>3 </s>
            <r>New </r>
        </Record>
        <Record>
            <s>1 </s>
            <r>Fixed </r>
        </Record>
    </faults>
</Record>

The code done so far:

File xmlFile=new File("demo.xml");
                byte[] b= Files.readAllBytes(xmlFile.toPath());
                String xml=new String(b);
                DocumentBuilderFactory dbFactory=DocumentBuilderFactory.newDefaultInstance();
                DocumentBuilder dBuilder=dbFactory.newDocumentBuilder();
                Document doc=dBuilder.parse(new InputSource(new StringReader(xml)));
                NodeList Records=doc.getElementsByTagName("Records");
                NodeList RecordOuter,RecordInnerList,RecordInner,faults,faultChildren;
                Node faultNode;
                for(int i=0;i<Records.getLength();i++)
                {
                    RecordOuter=((Element)Records.item(i)).getElementsByTagName("Record");
                    faults=((Element)RecordOuter.item(0)).getElementsByTagName("faults");
                    faultChildren=faults.item(0).getChildNodes();
                    for(int j=0;j<faultChildren.getLength();j++)
                    {
                        faultNode=faultChildren.item(j);
                        RecordInnerList=faultNode.getChildNodes();
                        for(int k=0;k<RecordInnerList.getLength();k++)
                        {
                            RecordInner=(NodeList) RecordInnerList.item(k);
                            NodeList RecordInnerChildren=RecordInner.item(1).getChildNodes();
                        }
                    }
                }
            }

I am not getting expected result from this code!

Answer 1

The method getElementsByTagName() searches all descendants, not just immediate children, so it's the wrong choice if you want to process the document one level at a time using nested loops.

Does it have to be DOM? Other more recent Java libraries for XML (such as JDOM2 or XOM) are so much nicer. Personally, I would always use higher-level languages such as XSLT/XQuery/XPath. But without knowing what your project is trying to achieve, or what the constraints are, I can't advise on that.