对xml文件的简单解析

Posted 2020-08-11 wdnnccey

package com.eprobj.demo;

import java.io.IOException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class Xml {
    
    public static void main(String[] args) {
        //获取节点个数，以及节点属性。
//        demo1();
        //获取节点个数，以及节点属性， 前提是知道属性有且只有一个时候，所使用的方法。
//        demo2();
        ////获取节点个数，以及节点属性,以及子节点信息。
        demo3();
    }

    private static void demo3() {
        DocumentBuilderFactory  dbf = DocumentBuilderFactory.newInstance();
        try {
            DocumentBuilder db = dbf.newDocumentBuilder();
            Document document =    db.parse("books.xml");
            //通过book标签获取相应的节点
            NodeList bookList = document.getElementsByTagName("book");
            System.out.println("一共有"+bookList.getLength()+"本书！");
            //遍历每一个book节点
            for(int i=0; i<bookList.getLength(); i++){
                Node book = bookList.item(i);
                //获取book节点的所有属性
                NamedNodeMap attrMap = book.getAttributes();
                System.out.println("第"+(i+1)+"本书共有"+attrMap.getLength()+"个属性.");
                //遍历book的属性
                for (int j = 0; j < attrMap.getLength(); j++) {
                    //属性键值对
                    Node attrNode = attrMap.item(j);
                    System.out.println("属性名:"+attrNode.getNodeName());
                    System.out.println("属性值:"+attrNode.getNodeValue());
                    
                    //获取节点下的所有子节点
                    NodeList childList =book.getChildNodes();
                    System.out.println("第"+(i+1)+"本书共有"+childList.getLength()+"子节点!");
                    //遍历节点，获取节点名称
                    for (int k = 0; k < childList.getLength(); k++) {
                        Node childNode = childList.item(k);
                        //如果当前节点是文字节点的话，只显示NodeNmae();
                        if(childNode.getNodeType() == Node.ELEMENT_NODE)
                        System.out.println(childList.item(k).getNodeName());
                    }
                }
            }
        } catch (ParserConfigurationException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SAXException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
    }

    private static void demo2() {
        DocumentBuilderFactory  dbf = DocumentBuilderFactory.newInstance();
        try {
            DocumentBuilder db = dbf.newDocumentBuilder();
            Document document =    db.parse("books.xml");
            //通过book标签获取相应的节点
            NodeList bookList = document.getElementsByTagName("book");
            System.out.println("一共有"+bookList.getLength()+"本书！");
            //遍历每一个book节点
            //遍历每一个book节点
            for(int i=0; i<bookList.getLength(); i++){
                Node book = bookList.item(i);
                //获取book节点的所有属性
                NamedNodeMap attrMap = book.getAttributes();
                System.out.println("第"+(i+1)+"本书共有"+attrMap.getLength()+"个属性.");
                //遍历book的属性
                for (int j = 0; j < attrMap.getLength(); j++) {
                    //属性键值对
                    Node attrNode = attrMap.item(j);
                    System.out.println("属性名:"+attrNode.getNodeName());
                    System.out.println("属性值:"+attrNode.getNodeValue());
                }
            }
        } catch (ParserConfigurationException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SAXException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    private static void demo1() {
        DocumentBuilderFactory  dbf = DocumentBuilderFactory.newInstance();
        try {
            DocumentBuilder db = dbf.newDocumentBuilder();
            Document document =    db.parse("books.xml");
            //通过book标签获取相应的节点
            NodeList bookList = document.getElementsByTagName("book");
            System.out.println("一共有"+bookList.getLength()+"本书！");
            
            //遍历每一个book节点
            for(int i=0; i<bookList.getLength(); i++){
                Node book = bookList.item(i);
                //获取book节点的所有属性
                NamedNodeMap attrMap = book.getAttributes();
                System.out.println("第"+(i+1)+"本书共有"+attrMap.getLength()+"个属性.");
                //遍历book的属性
                for (int j = 0; j < attrMap.getLength(); j++) {
                    //属性键值对
                    Node attrNode = attrMap.item(j);
                    System.out.println("属性名:"+attrNode.getNodeName());
                    System.out.println("属性值:"+attrNode.getNodeValue());
                    
                }
            }
        } catch (ParserConfigurationException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SAXException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }
}

 

使用了两种方式。在代码中已经体现出来。

books.xml使用的是相对路径。

<?xml version="1.0"?>
<bookstore>
<book id="1">
<name>格林童话</name>
<author>轨迹<author>
<language>english</language>
<year>2016</year>

</book>

<book id="2">
<name>格林童话</name>
<author>轨迹<author>
<language>english</language>
<price>20</price>
</book>
</bookstore>