👀 Views: 89 💬 Answers: 1 📅 Created: 2025-06-14

xml parsing java Java

I'm trying to parse a custom XML format in Java that contains mixed content, with elements that contain both text and child nodes. The XML structure is intended to define a series of tasks, where each task can have a name, an optional description, and multiple sub-tasks. Here's a simplified version of the XML I need to parse: ```xml <tasks> <task> <name>Task 1</name> <description>This is task one.</description> <sub-task>Sub-task 1.1</sub-task> <sub-task>Sub-task 1.2</sub-task> </task> <task> <name>Task 2</name> <description>This is task two with more details.</description> <sub-task>Sub-task 2.1</sub-task> </task> </tasks> ``` I've been using the `javax.xml.parsers.DocumentBuilder` to parse the XML, but I'm running into issues when trying to extract the text from both the `description` and the `sub-task` elements. The text content is not coming through as expected, and sometimes I end up with empty strings or even a `NullPointerException`. Here's the code snippet I've written so far: ```java import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import org.w3c.dom.*; public class XMLParser { public static void main(String[] args) { try { DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); Document doc = builder.parse("tasks.xml"); NodeList taskList = doc.getElementsByTagName("task"); for (int i = 0; i < taskList.getLength(); i++) { Element task = (Element) taskList.item(i); String name = task.getElementsByTagName("name").item(0).getTextContent(); String description = task.getElementsByTagName("description").item(0).getTextContent(); System.out.println("Task: " + name); System.out.println("Description: " + description); NodeList subTasks = task.getElementsByTagName("sub-task"); for (int j = 0; j < subTasks.getLength(); j++) { String subTask = subTasks.item(j).getTextContent(); System.out.println("Sub-task: " + subTask); } } } catch (Exception e) { e.printStackTrace(); } } } ``` When I run this code, it sometimes throws a `NullPointerException` on the `getElementsByTagName` calls, especially when the `description` tag is missing for a task. I've tried adding null checks, but I'm not sure I'm handling the mixed content correctly. Is there a better way to traverse the nodes that would handle cases where elements might be missing? Any advice on best practices for parsing this kind of XML structure in Java would be greatly appreciated! This is happening in both development and production on Windows 10. Any help would be greatly appreciated!