Java JDOM解析器 - 查詢XML文件

演示範例

這是需要我們查詢的輸入XML檔案：

<?xml version="1.0"?>
<cars>
<supercars company="Ferrari">
<carname type="formula one">Ferarri 101</carname>
<carname type="sports car">Ferarri 201</carname>
<carname type="sports car">Ferarri 301</carname>
</supercars>
<supercars company="Lamborgini">
<carname>Lamborgini 001</carname>
<carname>Lamborgini 002</carname>
<carname>Lamborgini 003</carname>
</supercars>
<luxurycars company="Benteley">
<carname>Benteley 1</carname>
<carname>Benteley 2</carname>
<carname>Benteley 3</carname>
</luxurycars>
</cars>

演示範例：

QueryXmlFileDemo.java

import java.io.File;
import java.io.IOException;
import java.util.List;

import org.jdom2.Attribute;
import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.JDOMException;
import org.jdom2.input.SAXBuilder;


public class QueryXmlFileDemo {
   public static void main(String[] args) {
      try {
         File inputFile = new File("input.txt");

         SAXBuilder saxBuilder = new SAXBuilder();
         Document document = saxBuilder.build(inputFile);

         System.out.println("Root element :" 
            + document.getRootElement().getName());

         Element classElement = document.getRootElement();

         List<Element> supercarList = classElement.getChildren("supercars");
         System.out.println("----------------------------");

         for (int temp = 0; temp < supercarList.size(); temp++) {    
            Element supercarElement = supercarList.get(temp);
            System.out.println("\nCurrent Element :" 
               + supercarElement.getName());
            Attribute attribute =  supercarElement.getAttribute("company");
            System.out.println("company : " 
               + attribute.getValue() );
            List<Element> carNameList = supercarElement.getChildren("carname");
            for (int count = 0; 
               count < carNameList.size(); count++) {	 
               Element carElement = carNameList.get(count);
               System.out.print("car name : ");
               System.out.println(carElement.getText());
               System.out.print("car type : ");
               Attribute typeAttribute = carElement.getAttribute("type");
               if(typeAttribute !=null)
                  System.out.println(typeAttribute.getValue());
               else{
                  System.out.println("");
               }
            }	            
         }
      }catch(JDOMException e){
         e.printStackTrace();
      }catch(IOException ioe){
         ioe.printStackTrace();
      }
   }
}

這將產生以下結果：

Root element :cars
----------------------------

Current Element :supercars
company : Ferrari
car name : Ferarri 101
car type : formula one
car name : Ferarri 201
car type : sports car
car name : Ferarri 301
car type : sports car

Current Element :supercars
company : Lamborgini
car name : Lamborgini 001
car type : 
car name : Lamborgini 002
car type : 
car name : Lamborgini 003
car type :