How to fetch the child nodes of repeated elements in java for nodelist

问题

I need to fetch the value of the name element which is a child of an e element:

<a>
    <b>
        <c>
            <d>
                <e><name>123</name></e>
                <e><name>456</name></e>
                <e><name>456</name></e>
            </d>
        </c>
    </b>
</a>

This is my code:

NodeList lineItemAttributeChildrenList =
    doc.getElementsByTagName("e").item(0).getChildNodes();

if(lineItemAttributeChildrenList != null &&
   lineItemAttributeChildrenList.getLength() > 0) {
    System.out.println("Inside if and checking length" +
                       lineItemAttributeChildrenList.getLength());

    for (int i = 0; i < lineItemAttributeChildrenList.getLength(); i++) {
        System.out.println("i " + i);
        System.out.println("inside for");
        System.out.println("name==============" +
                           lineItemAttributeChildrenList.item(i).getNodeName());
        System.out.println("value==============" +
                           lineItemAttributeChildrenList.item(i).getTextContent());
    }
}

From the above code I just get the first inner element name value for the e element, but for the remaining 2 I am not able to get those values. It is not going to the second e element in the for loop.

回答1:

You are getting 0th element of the NodeList of "e" elements.

    NodeList LineItemAttributeChildrenList = doc.getElementsByTagName("e").item(0).getChildNodes();
...
 for (int i = 0; i < LineItemAttributeChildrenList.getLength(); i++) {

You should iterate through the NodeList itself instead of the children of the first element. Here is how your new code would look:

    NodeList LineItemAttributeChildrenList = doc.getElementsByTagName("e");
    if (LineItemAttributeChildrenList != null && LineItemAttributeChildrenList.getLength() > 0) 
    {
        System.out.println("Inside if and checking length"+LineItemAttributeChildrenList.getLength());
        for (int i = 0; i < LineItemAttributeChildrenList.getLength(); i++) {
            System.out.println("i "+i);
            System.out.println("inside for");
            System.out.println("name=============="+LineItemAttributeChildrenList.item(i).getNodeName());
            System.out.println("value=============="+LineItemAttributeChildrenList.item(i).getTextContent());
        }
     }

回答2:

You are accessing only first item thats why you are getting 1 result. try below. Check 'z' in eNodes.item(z)

    NodeList eNodes = doc.getElementsByTagName("e");
    for (int z = 0; z < eNodes.getLength(); z++) {
        NodeList LineItemAttributeChildrenList = eNodes.item(z).getChildNodes();
        if (LineItemAttributeChildrenList != null && LineItemAttributeChildrenList.getLength() > 0) {
            System.out.println("Inside if and checking length" + LineItemAttributeChildrenList.getLength());
            for (int i = 0; i < LineItemAttributeChildrenList.getLength(); i++) {
                System.out.println("i " + i);

                System.out.println("inside for");
                System.out.println("name==============" + LineItemAttributeChildrenList.item(i).getNodeName());
                System.out.println("value==============" + LineItemAttributeChildrenList.item(i).getTextContent());

            }

        }

    }

You can directly get name nodes and iterate over it to get values as below

NodeList nameNodes = doc.getElementsByTagName("name");
for (int i = 0; i < nameNodes.getLength(); i++) {
    String value = nameNodes.item(i).getTextContent();
    System.out.println("value==============" + value);
}

回答3:

You are iterating over wrong Node

Take a look below:

NodeList LineItemAttributeChildrenList = doc.getElementsByTagName("e"); // Finding all 'e' s
          if (LineItemAttributeChildrenList != null && LineItemAttributeChildrenList.getLength() > 0) {
                  System.out.println("Inside if and checking length"+LineItemAttributeChildrenList.getLength());
                    // Iterate over 'e' s
                    for (int i = 0; i < LineItemAttributeChildrenList.getLength(); i++) {
                        System.out.println("i "+i);
                         Node e = LineItemAttributeChildrenList.item(i); 
                         // Access the 'name' node for this 'e'
                         Node name = e.getChildNodes()[0] // We know that 'e' has only one child.
                             System.out.println("name=============="+name.getNodeName());
                            System.out.println("value=============="+name.getTextContent());


                            }


                    }

来源：https://stackoverflow.com/questions/32867452/how-to-fetch-the-child-nodes-of-repeated-elements-in-java-for-nodelist

标签

java

dom

nodelist