java 如何使用org.w3c.dom操作XML文件

2024-04-02 19:04:59 425人浏览薄情痞子

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摘要

本篇介绍在java中，如何使用org.w3c.dom中的相关内容来操作XML文件。包括：如何在内存中构建XML文件并写入磁盘；如何从磁盘读取XML文件到内存；

本篇介绍在java中，如何使用org.w3c.dom中的相关内容来操作XML文件。包括：

如何在内存中构建XML文件并写入磁盘；
如何从磁盘读取XML文件到内存；
如何添加注释，读取注释；
如何添加属性，读取属性；
如何添加子元素，读取子元素；

下面直接贴出样例代码：


import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transfORM.OutpuTKEys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
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 java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Date;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;
public class XMLSample{
	private static void writeXML(Document document, String filePath) {
 
		TransformerFactory transFactory = TransformerFactory.newInstance();
		Transformer transformer = null;
		try {
			String parent = new File(filePath).getParent();
			File pDir = new File(parent);
			if (!pDir.exists()) {
				pDir.mkdirs();
			}
			OutputStream os = new FileOutputStream(new File(filePath));
			transformer = transFactory.newTransformer();
			transformer.setOutputProperty(OutputKeys.INDENT, "yes");
			transformer.setOutputProperty(OutputKeys.ENcoding, "utf-8");
			DOMSource source = new DOMSource();
			source.setNode(document);
			StreamResult result = new StreamResult();
			result.setOutputStream(os);
			transformer.transform(source, result);
			os.flush();
		} catch (TransformerConfigurationException e) {
			e.printStackTrace();
		} catch (TransformerException e) {
			e.printStackTrace();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
 
	private static Document readXML(String file) {
 
		try {
            // 得到DOM解析器的工厂实例
			DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
            // 从DOM工厂中获得DOM解析器
			DocumentBuilder dbBuilder = dbFactory.newDocumentBuilder();
            // 把要解析的xml文档读入DOM解析器
			Document doc = dbBuilder.parse(file);
			return doc;
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}
 
	public static void showXMLDetail() { 
		Document document = readXML(mapperFilePath);
        // 获取标签名为"dataset"的元素
		Node mapper = document.getElementsByTagName("dataset").item(0);
 
        // 下面依次读取dataset元素的每个子元素，每个子元素的标签名字为node
		for (int i = 0; i < mapper.getChildNodes().getLength(); i++) {
			Node node = mapper.getChildNodes().item(i);
			String s = item.getNodeName();
			if(s.toLowerCase().equals("#comment")){
				System.out.println("这是注释内容: "+node.getTextContent());
			}else if(s.toLowerCase().equals("#text")){
				System.out.println("呐，这是标签之外的文本: "+node.getTextContent());
			}else if ("node".equals(s)) {
				// 获取元素属性的值
				String column = item.getAttributes().getNamedItem("column").getNodeValue();
				String field = item.getAttributes().getNamedItem("property").getNodeValue();
			}else{
				// 其他的就不要了
			} 
		} 
	}
 
	public static void generateXML(){
		try {
			Element root;
			Set<String> set = new HashSet<>();
			set.add("node");
			DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
			factory.setNamespaceAware(true);
			DocumentBuilder documentBuilder = null;
			documentBuilder = factory.newDocumentBuilder();
			Document document = documentBuilder.newDocument();
			root = document.createElement("dataset");
			document.appendChild(root);
			set.forEach(p -> {
				Element element = document.createElement(p);
				element.setAttribte("column","haha");
				element.setAttribte("property","heihei");
				root.appendChild(element);
			});
			writeXML(document, "d:/allTables.xml");
		} catch (ParserConfigurationException e) {
			e.printStackTrace();
		}
	}
}

Java操作XML（使用org.w3c.dom）

一、创建DOM


XMLBuilder.java
 
 用于创建ＤＯＭ，Root结点 

package rochoc.xml.oper; 
import java.io.File;
import java.io.IOException; 
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException; 
import org.apache.log4j.Logger;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.xml.sax.SAXException;
 

 
public class XmlBuilder
{
    
    public XmlBuilder(String path)
    {
        this.path=path;
        init();
    }
     
    
    public void init()
    {
        buildDocument();
        buildRoot();
    }
     
    
    private void buildDocument()
    {
        DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();
        try
        {
            DocumentBuilder builder=factory.newDocumentBuilder();
            logger.debug("Construct document builder success.");
            doc=builder.parse(new File(path));            
            logger.debug("Build xml document success.");
        }catch(ParserConfigurationException e)
        {
            logger.error("Construct document builder error:"+e);
        }catch(SAXException e)
        {
            logger.error("Parse xml file error:"+e);
        }catch(IOException e)
        {
            logger.error("Read xml file error:"+e);
        }
    }
     
    
    private void buildRoot()
    {
        root=doc.getDocumentElement();
    }
     
    
    public Document getDoc()
    {
        return doc;
    }
    
    public void setDoc(Document doc)
    {
        this.doc = doc;
    }
    
    public String getPath()
    {
        return path;
    }
    
    public void setPath(String path)
    {
        this.path = path;
    }
    
    public Element getRoot()
    {
        return root;
    }
    
    public void setRoot(Element root)
    {
        this.root = root;
    }
    
    private String path=null;//xml文件路径
    private Document doc=null;//xml文件对应的document
    private Element root=null;//xml文件的根结点
    private Logger logger=Logger.getLogger(getClass().getName());
}

二、查找，插入，删除，修改


XmlOper.java
 
 用于操作ＸＭＬ文件，包括查找、新增、删除、修改结点 
 
package rochoc.xml.oper; 
import java.util.ArrayList; 
import org.apache.log4j.Logger;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
 

 
public class XmlOper
{
    
    private XmlOper()
    {        
    }
     
    
    public static NodeList getNodeList(Element parent)
    {
        return parent.getChildNodes();
    }
     
    
    public static Element [] getElementsByName(Element parent,String name)
    {
        ArrayList resList=new ArrayList();
        NodeList nl=getNodeList(parent);
        for(int i=0;i<nl.getLength();i++)
        {
            Node nd=nl.item(i);
            if(nd.getNodeName().equals(name))
            {
                resList.add(nd);
            }
        }
        Element [] res=new Element [resList.size()];
        for(int i=0;i<resList.size();i++)
        {
            res[0]=(Element)resList.get(i);
        }        
        logger.debug(parent.getNodeName()+"'s children of "+name+
                "'s num:"+res.length);
        return res;
    }
     
    
    public static String getElementName(Element element)
    {
        return element.getNodeName();
    }
     
    
    public static String getElementValue(Element element)
    {
        NodeList nl=element.getChildNodes();
        for(int i=0;i<nl.getLength();i++)
        {
            if(nl.item(i).getNodeType()==Node.TEXT_NODE)//是一个Text Node
            {            
                logger.debug(element.getNodeName()+" has a Text Node.");
                return element.getFirstChild().getNodeValue();
            }
        }   
        logger.error(element.getNodeName()+" hasn't a Text Node.");
        return null;
    }
     
    
    public static String getElementAttr(Element element,String attr)
    {
        return element.getAttribute(attr);
    }
     
    
    public static void setElementValue(Element element,String val)
    {
        Node node=element.getOwnerDocument().createTextNode(val);
        NodeList nl=element.getChildNodes();
        for(int i=0;i<nl.getLength();i++)
        {
            Node nd=nl.item(i);
            if(nd.getNodeType()==Node.TEXT_NODE)//是一个Text Node
            {            
                  nd.setNodeValue(val);
                  logger.debug("modify "+element.getNodeName()+"'s node value succe.");
                  return;
            }
        }   
        logger.debug("new "+element.getNodeName()+"'s node value succe.");
        element.appendChild(node);        
    }
     
    
    public static void setElementAttr(Element element,
            String attr,String attrVal)
    {
        element.setAttribute(attr,attrVal);
    }     
     
    
    public static void addElement(Element parent,Element child)
    {
        parent.appendChild(child);
    }
     
    
    public static void addElement(Element parent,String tagName)
    {        
        Document doc=parent.getOwnerDocument();
        Element child=doc.createElement(tagName);
        parent.appendChild(child);
    }
     
    
    public static void addElement(Element parent,String tagName,String text)
    {
        Document doc=parent.getOwnerDocument();
        Element child=doc.createElement(tagName);
        setElementValue(child,text);
        parent.appendChild(child);
    }
     
    
    public static void removeElement(Element parent,String tagName)
    {
        logger.debug("remove "+parent.getNodeName()+"'s children by tagName "+tagName+" begin...");
        NodeList nl=parent.getChildNodes();
        for(int i=0;i<nl.getLength();i++)
        {
            Node nd=nl.item(i);
            if(nd.getNodeName().equals(tagName))
            {
                parent.removeChild(nd);
                logger.debug("remove child '"+nd+"' success.");
            }
        }
        logger.debug("remove "+parent.getNodeName()+"'s children by tagName "+tagName+" end.");
    }     
     
       
    static Logger logger=Logger.getLogger("XmlOper");
}

三、新建XML文件


XmlCreater.java
 
 用于创建ＸＭＬ文件 

package rochoc.xml.oper; 
import java.io.File; 
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult; 
import org.apache.log4j.Logger;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
 

 
public class XmlCreater
{
    
    public XmlCreater(String path)
    {
        this.path=path;
        init();
    }
     
    
    private void init()
    {
        DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();
        try
        {
            DocumentBuilder builder=factory.newDocumentBuilder();
            doc=builder.newDocument();//新建DOM
        }catch(ParserConfigurationException e)
        {
            logger.error("Parse DOM builder error:"+e);
        }
    }
     
    
    public Element createRootElement(String rootTagName)
    {     
        if(doc.getDocumentElement()==null)
        {
            logger.debug("create root element '"+rootTagName+"' success.");
            Element root=doc.createElement(rootTagName);
            doc.appendChild(root);
            return root;
        }
        logger.warn("this dom's root element is exist,create fail.");
        return doc.getDocumentElement();
    }
     
    
    public Element createElement(Element parent,String tagName)
    {
        Document doc=parent.getOwnerDocument();
        Element child=doc.createElement(tagName);
        parent.appendChild(child);        
        return child;
    }
     
    
    public Element createElement(Element parent,String tagName,String value)
    {
        Document doc=parent.getOwnerDocument();
        Element child=doc.createElement(tagName);
        XmlOper.setElementValue(child,value);
        parent.appendChild(child);
        return child;
    }
     
    
    public void createAttribute(Element parent,String attrName,String attrValue)
    {
        XmlOper.setElementAttr(parent,attrName,attrValue);        
    }
     
    
    public void buildXmlFile()
    {
        TransformerFactory tfactory=TransformerFactory.newInstance();
        try
        {
            Transformer transformer=tfactory.newTransformer();
            DOMSource source=new DOMSource(doc);
            logger.debug("New DOMSource success.");
            StreamResult result=new StreamResult(new File(path));
            logger.debug("New StreamResult success.");
            transformer.setOutputProperty("encoding","GBK");
            transformer.transform(source,result);
            logger.debug("Build XML File '"+path+"' success.");
        }catch(TransformerConfigurationException e)
        {
            logger.error("Create Transformer error:"+e);
        }catch(TransformerException e)
        {
            logger.error("Transformer XML file error:"+e);
        }
    }
     
    
    public Document getDoc()
    {
        return doc;
    }
    
    public void setDoc(Document doc)
    {
        this.doc = doc;
    }
    
    public String getPath()
    {
        return path;
    }
    
    public void setPath(String path)
    {
        this.path = path;
    }
    
    private Logger logger = Logger.getLogger(getClass().getName());
    private Document doc=null;//新创建的DOM
    private String path=null;//生成的XML文件绝对路径
}

以上为个人经验，希望能给大家一个参考，也希望大家多多支持编程网。

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