以下是解析時使用DOM4J解析器文件使用的步驟。
匯入XML相關的軟體包。
建立一個SAXReader
從檔案或資料流建立一個文件
通過呼叫document.selectNodes()獲取使用XPath表示式所需的節點
提取根元素
遍歷節點列表。
檢查屬性
檢查子元素
匯入XML相關的軟體包
import java.io.*; import java.util.*; import org.dom4j.*;
建立一個DocumentBuilder
SAXBuilder saxBuilder = new SAXBuilder();
從檔案或資料流建立一個文件
File inputFile = new File("input.txt"); SAXBuilder saxBuilder = new SAXBuilder(); Document document = saxBuilder.build(inputFile);
提取根元素
Element classElement = document.getRootElement();
Examine attributes
//returns specific attribute valueOf("@attributeName");
檢查子元素
//returns first child node selectSingleNode("subelementName");
這是輸入需要解析xml檔案:
<?xml version="1.0"?> <class> <student rollno="393"> <firstname>dinkar</firstname> <lastname>kad</lastname> <nickname>dinkar</nickname> <marks>85</marks> </student> <student rollno="493"> <firstname>Vaneet</firstname> <lastname>Gupta</lastname> <nickname>vinni</nickname> <marks>95</marks> </student> <student rollno="593"> <firstname>jasvir</firstname> <lastname>singn</lastname> <nickname>jazz</nickname> <marks>90</marks> </student> </class>
演示範例:
DOM4JParserDemo.java
package com.yiibai.xml; import java.io.File; import java.util.List; import org.dom4j.Document; import org.dom4j.DocumentException; import org.dom4j.Element; import org.dom4j.Node; import org.dom4j.io.SAXReader; public class DOM4JParserDemo { public static void main(String[] args) { try { File inputFile = new File("input.txt"); SAXReader reader = new SAXReader(); Document document = reader.read( inputFile ); System.out.println("Root element :" + document.getRootElement().getName()); Element classElement = document.getRootElement(); List<Node> nodes = document.selectNodes("/class/student" ); System.out.println("----------------------------"); for (Node node : nodes) { System.out.println("\nCurrent Element :" + node.getName()); System.out.println("Student roll no : " + node.valueOf("@rollno") ); System.out.println("First Name : " + node.selectSingleNode("firstname").getText()); System.out.println("Last Name : " + node.selectSingleNode("lastname").getText()); System.out.println("First Name : " + node.selectSingleNode("nickname").getText()); System.out.println("Marks : " + node.selectSingleNode("marks").getText()); } } catch (DocumentException e) { e.printStackTrace(); } } }
這將產生以下結果:
Root element :class ---------------------------- Current Element :student Student roll no : First Name : dinkar Last Name : kad First Name : dinkar Marks : 85 Current Element :student Student roll no : First Name : Vaneet Last Name : Gupta First Name : vinni Marks : 95 Current Element :student Student roll no : First Name : jasvir Last Name : singn First Name : jazz Marks : 90