零教程

使用JDOM的步骤

以下是解析时使用JDOM解析器文档的步骤。

• 导入XML相关的软件包

• 创建一个SAXBuilder

• 从文件或流创建一个文档

• 提取根元素

• 检查属性

• 检查子元素

导入XML相关的软件包

import java.io.*
import java.util.*
import org.jdom2.*

创建DocumentBuilder

SAXBuilder saxBuilder = new SAXBuilder()

从文件或流创建一个文档

File inputFile = new File("input.txt")
SAXBuilder saxBuilder = new SAXBuilder()
Document document = saxBuilder.build(inputFile)

提取根元素

Element classElement = document.getRootElement()

检查属性

//returns specific attribute
getAttribute("attributeName") 

检查子元素

//returns a list of subelements of specified name
getChildren("subelementName") 
//returns a list of all child nodes
getChildren() 
//returns first child node
getChild("subelementName") 

演示示例

这是输入需要解析xml文件：

<?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>

%uA0

演示示例：

DomParserDemo.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 JDomParserDemo {
   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> studentList = classElement.getChildren()
         System.out.println("----------------------------")

         for (int temp = 0 temp < studentList.size() temp++) {    
            Element student = studentList.get(temp)
            System.out.println("\nCurrent Element :" 
               + student.getName())
            Attribute attribute =  student.getAttribute("rollno")
            System.out.println("Student roll no : " 
               + attribute.getValue() )
            System.out.println("First Name : " + student.getChild("firstname").getText())
            System.out.println("Last Name : "+ student.getChild("lastname").getText())
            System.out.println("Nick Name : "+ student.getChild("nickname").getText())
            System.out.println("Marks : "+ student.getChild("marks").getText())	            		
         }
      }catch(JDOMException e){
         e.printStackTrace()
      }catch(IOException ioe){
         ioe.printStackTrace()
      }
   }
}

这将产生以下结果：

Root element :class
----------------------------

Current Element :student
Student roll no : 393
First Name : dinkar
Last Name : kad
Nick Name : dinkar
Marks : 85

Current Element :student
Student roll no : 493
First Name : Vaneet
Last Name : Gupta
Nick Name : vinni
Marks : 95

Current Element :student
Student roll no : 593
First Name : jasvir
Last Name : singn
Nick Name : jazz
Marks : 90