Java解析XML:Jdom解析和SAX解析

今天看了Java解析XML的几种方法,记录一下

　　　　1、Jdom解析

　　　　　　(1)读取XML内容

　　

　　private static void readXML() {
        // TODO Auto-generated method stub
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        try {
            Document document = JdomTools.getDocument("src/books.xml");
            // 找节点
            NodeList tagName = document.getElementsByTagName("name");
            Node item = tagName.item(1);
            // 获取节点文本
            String textContent = item.getTextContent();
            System.out.println(textContent);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

　　　　(2)写入新节点

　　

　　public static void write2XML() {
        try {
            
            //获取要写入新节点的原dom树信息
            Document document = JdomTools.getDocument("src/books.xml");
            NodeList nodeList = document.getElementsByTagName("book");
            Node node = nodeList.item(0);
            //实例化一个新的节点对象
            Element element = document.createElement("nums");
            element.setTextContent("132");
            //追加到父节点中
            node.appendChild(element);
            //将修改后的新的dom覆盖掉原来的dom文件
            JdomTools.write2Xml(document, "src/books.xml");
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

　　(3)移除子节点

 public static void removeNode(){
        try {
            Document document = JdomTools.getDocument("src/books.xml");
    ///方法一
            //Node node = document.getElementsByTagName("nums").item(0);
            
            //System.out.println(node.getParentNode().getTextContent());
            //node.getParentNode().removeChild(node);
    ///方法二
            
            JdomTools.deleteNode(document.getElementsByTagName("book").item(0),document.getElementsByTagName("nums").item(0));
            JdomTools.write2Xml(document, "src/books.xml");
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

　　(4)替换子节点

 public static void replaceNode(){
        try {
            Document document = JdomTools.getDocument("src/books.xml");
            Element element = document.createElement("添加的");
            element.setTextContent("这是测试的内容");
            JdomTools.replaceNodeText(element, document.getElementsByTagName("price").item(0));
            JdomTools.write2Xml(document, "src/books.xml");
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

　　JdomTools工具类

package com.xujingyang.utils;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.DOMException;
import org.w3c.dom.Document;
import org.w3c.dom.Node;

public class JdomTools {
    
    /**
     * 查找document
     * @param path
     * @return
     * @throws Exception 
     */
    public  static Document getDocument(String path) throws Exception{
        // 获取DocumentBuilder实例
        DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
        // 获取document对象
        return builder.parse(path);
    }

    
    /**
     * 删除节点
     * @param path
     * @param oldChild
     * @param document 
     * @throws Exception
     */
    public static void deleteNode(Node document,Node oldChild ) throws Exception{
        //移除document节点下的子节点
        document.removeChild(oldChild);
    }
    
    /**
     * 替换子节点
     * @param document
     * @param newChild
     * @param oldChild
     */
    public static void replaceNodeText(Node newChild,Node oldChild){
        //oldChild替换替换为新的newChild节点
        oldChild.getParentNode().replaceChild(newChild, oldChild);
    }
    /**
     * 写入新节点
     * @param document
     * @param path
     * @throws Exception
     */
    public static void write2Xml(Document document,String path) throws Exception{
        //获取Transformer对象
        Transformer transformer = TransformerFactory.newInstance().newTransformer();
        //把写好的新的document树中写入新的文件(一般是覆盖原文件)
        transformer.transform(new DOMSource(document), new StreamResult(path));
    }
}

2、SAX解析

　　　　SAX
　　　　　　Simple API for XML
　　　　开发包
　　　　　　JAXP：是SUN公司推出的解析标准实现
　　　　　　java API for xml Processing
　　　　主要包含的类和接口
　　　　　　org.w3c.dom:提供DOM方式解析XML的标准接口
　　　　　　org.xml.sax:提供SAX方式解析XML的标准接口
　　　　　　javax.xml:提供了解析XML文档的类

　　(1)普通的解析方式

package com.xujingyang.utils;


import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class saxDom {
    public static void getDom(String XMLpath) throws Exception{
        SAXParserFactory parserFactory = SAXParserFactory.newInstance();
        SAXParser saxParser = parserFactory.newSAXParser();
        saxParser.parse(XMLpath, new DefaultHandler(){
            protected String result="";
            @Override 
            public void startDocument() throws SAXException {
                //开始解析文档
                super.startDocument();
                result+="document begin
";
            }

            @Override
            public void startElement(String uri, String localName,
                    String qName, Attributes attributes) throws SAXException {
                //开始解析节点
                super.startElement(uri, localName, qName, attributes);
                result+="
element begin";
            }
            @Override
            public void characters(char[] ch, int start, int length)
                    throws SAXException {
                //开始读取节点内容
                super.characters(ch, start, length);
                result+=String.copyValueOf(ch, start, length);
            }

            @Override
            public void endDocument() throws SAXException {
                //结束解析文档
                super.endDocument();
                result+="
document end";
                System.out.println(result);
            }

            @Override
            public void endElement(String uri, String localName, String qName)
                    throws SAXException {
                //结束解析节点
                super.endElement(uri, localName, qName);
                result+="
element end";
            }
        });
    }
    
}

　　(2)封装JavaBean的解析方式

　　

package com.xujingyang.utils;


import java.util.ArrayList;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;

import com.xujingyang.domain.Book;

public class sax4bean {
    public static ArrayList<Book> getBooks() throws Exception{
        //对象集合
        final ArrayList<Book> books=new ArrayList<Book>();
        SAXParser saxParser = SAXParserFactory.newInstance().newSAXParser();
        XMLReader reader = saxParser.getXMLReader();
        reader.setContentHandler(new DefaultHandler(){
            Book book=null;
            String nodeString;//做判断是否节点是要找的属性节点

            @Override
            public void startElement(String uri, String localName,
                    String qName, Attributes attributes) throws SAXException {
                super.startElement(uri, localName, qName, attributes);
                //判断节点名称是要找的对象就初始化bean
                if("book".equals(qName)){
                    book=new Book();
                }
                nodeString=qName;
                
            }
            @Override
            public void characters(char[] ch, int start, int length)
                    throws SAXException {
                super.characters(ch, start, length);
                if(book!=null){
                    String textString=new String(ch, start, length);
                    if("name".equals(nodeString)){
                        book.setName(textString);
                    }else if ("aothour".equals(nodeString)) {
                        book.setAothour(textString);
                    }else if ("price".equals(nodeString)) {
                        book.setPrice(Float.parseFloat(textString));
                    }
                }
            }


            @Override
            public void endElement(String uri, String localName, String qName)
                    throws SAXException {
                // TODO Auto-generated method stub
                super.endElement(uri, localName, qName);
                //每次节点解析结束就要判断是否是一个对象结束,如果结束就将对象置空
                if("book".equals(qName)){
                    books.add(book);
                    book=null;
                }
                //每次节点名称都要置空,否则就会读到空文本
                nodeString=null;
            }
        });
        reader.parse("src/books.xml");
        
        return books;
    }
}

　　对象类

package com.xujingyang.domain;

public class Book {
    private String name;
    private String aothour;
    private float price;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getAothour() {
        return aothour;
    }
    public void setAothour(String aothour) {
        this.aothour = aothour;
    }
    public float getPrice() {
        return price;
    }
    public void setPrice(float price) {
        this.price = price;
    }
    @Override
    public String toString() {
        return "Book [name=" + name + ", aothour=" + aothour + ", price="
                + price + "]";
    }
    
}

要解析的XML文档

<?xml version="1.0" encoding="UTF-8" standalone="no"?><books>
    <book>
        <name>三国演义</name>
        <aothour>罗贯中</aothour>
        <price>22</price>
        
    </book>
    <book>
        <name>西游记</name>
        <aothour>吴承恩</aothour>
        <price>24</price>
    </book>
</books>