JAVA增删改查XML文件

　　最近总是需要进行xml的相关操作。

　　不免的要进行xml的读取修改等，于是上网搜索，加上自己的小改动，整合了下xml的常用操作。

　　读取XML配置文件

　　首先我们需要通过DocumentBuilderFactory获取xml文件的工厂实例。

DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
        dbf.setIgnoringElementContentWhitespace(true);

　　创建文档对象

 DocumentBuilder db = dbf.newDocumentBuilder();
             Document doc = db.parse(xmlPath); // 使用dom解析xml文件

　　最后遍历列表，进行数据提取

 NodeList sonlist = doc.getElementsByTagName("son");
             for (int i = 0; i < sonlist.getLength(); i++) // 循环处理对象
             {
                 Element son = (Element)sonlist.item(i);;

                 for (Node node = son.getFirstChild(); node != null; node = node.getNextSibling()){
                     if (node.getNodeType() == Node.ELEMENT_NODE){
                         String name = node.getNodeName();
                         String value = node.getFirstChild().getNodeValue();
                         System.out.println(name+" : "+value);
                     }
                 }
             }

　　全部代码

 public static void getFamilyMemebers(){
         DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
         dbf.setIgnoringElementContentWhitespace(true);
         try {
             DocumentBuilder db = dbf.newDocumentBuilder();
             Document doc = db.parse(xmlPath); // 使用dom解析xml文件

             NodeList sonlist = doc.getElementsByTagName("son");
             for (int i = 0; i < sonlist.getLength(); i++) // 循环处理对象
             {
                 Element son = (Element)sonlist.item(i);;

                 for (Node node = son.getFirstChild(); node != null; node = node.getNextSibling()){
                     if (node.getNodeType() == Node.ELEMENT_NODE){
                         String name = node.getNodeName();
                         String value = node.getFirstChild().getNodeValue();
                         System.out.println(name+" : "+value);
                     }
                 }
             }
         } catch (Exception e) {
             e.printStackTrace();
         }
     }

　　在XML文件中增加节点

　　差不多同样的步骤，先获取根节点，创建一个新的节点，向其中添加元素信息，最后把这个新节点添加到根节点中

 Element root = xmldoc.getDocumentElement();

             //删除指定节点

             Element son =xmldoc.createElement("son");
             son.setAttribute("id", "004");

             Element name = xmldoc.createElement("name");
             name.setTextContent("小儿子");
             son.appendChild(name);

             Element age = xmldoc.createElement("name");
             age.setTextContent("0");
             son.appendChild(age);

             root.appendChild(son);

　　最后不要忘记保存新增的文件，对源文件进行覆盖。

 TransformerFactory factory = TransformerFactory.newInstance();
             Transformer former = factory.newTransformer();
             former.transform(new DOMSource(xmldoc), new StreamResult(new File(xmlPath)));

　　全部代码：

     public static void createSon() {
         DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
         dbf.setIgnoringElementContentWhitespace(false);

         try{

             DocumentBuilder db=dbf.newDocumentBuilder();
             Document xmldoc=db.parse(xmlPath);

             Element root = xmldoc.getDocumentElement();

             //删除指定节点

             Element son =xmldoc.createElement("son");
             son.setAttribute("id", "004");

             Element name = xmldoc.createElement("name");
             name.setTextContent("小儿子");
             son.appendChild(name);

             Element age = xmldoc.createElement("name");
             age.setTextContent("0");
             son.appendChild(age);

             root.appendChild(son);
             //保存
             TransformerFactory factory = TransformerFactory.newInstance();
             Transformer former = factory.newTransformer();
             former.transform(new DOMSource(xmldoc), new StreamResult(new File(xmlPath)));

         }catch(Exception e){
             e.printStackTrace();
         }
     }

　　在XML中修改节点信息

　　通过XPath来获取目标节点

 public static Node selectSingleNode(String express, Element source) {
         Node result=null;
         XPathFactory xpathFactory=XPathFactory.newInstance();
         XPath xpath=xpathFactory.newXPath();
         try {
             result=(Node) xpath.evaluate(express, source, XPathConstants.NODE);
         } catch (XPathExpressionException e) {
             e.printStackTrace();
         }

         return result;
     }

　　获取目标节点，进行修改，完成后，保存文件。

 Element root = xmldoc.getDocumentElement();

             Element per =(Element) selectSingleNode("/father/son[@id='001']", root);
             per.getElementsByTagName("age").item(0).setTextContent("27");

             TransformerFactory factory = TransformerFactory.newInstance();
             Transformer former = factory.newTransformer();
             former.transform(new DOMSource(xmldoc), new StreamResult(new File(xmlPath)));

　　全部代码：

     public static void modifySon(){
         DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
         dbf.setIgnoringElementContentWhitespace(true);
         try{

             DocumentBuilder db=dbf.newDocumentBuilder();
             Document xmldoc=db.parse(xmlPath);

             Element root = xmldoc.getDocumentElement();

             Element per =(Element) selectSingleNode("/father/son[@id='001']", root);
             per.getElementsByTagName("age").item(0).setTextContent("27");

             TransformerFactory factory = TransformerFactory.newInstance();
             Transformer former = factory.newTransformer();
             former.transform(new DOMSource(xmldoc), new StreamResult(new File(xmlPath)));
         }catch(Exception e){
             e.printStackTrace();
         }
     }

　　删除XML中的节点

　　通过XPath获取目标节点， 进行删除，最后保存

             Element root = xmldoc.getDocumentElement();

             Element son =(Element) selectSingleNode("/father/son[@id='002']", root);
             root.removeChild(son);

             TransformerFactory factory = TransformerFactory.newInstance();
             Transformer former = factory.newTransformer();
             former.transform(new DOMSource(xmldoc), new StreamResult(new File(xmlPath)));

　　全部代码：

     public static void discardSon(){

         DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
         dbf.setIgnoringElementContentWhitespace(true);

         try{

             DocumentBuilder db=dbf.newDocumentBuilder();
             Document xmldoc=db.parse(xmlPath);

             Element root = xmldoc.getDocumentElement();

             Element son =(Element) selectSingleNode("/father/son[@id='002']", root);
             root.removeChild(son);

             TransformerFactory factory = TransformerFactory.newInstance();
             Transformer former = factory.newTransformer();
             former.transform(new DOMSource(xmldoc), new StreamResult(new File(xmlPath)));

         }catch(Exception e){
             e.printStackTrace();
         }
     }

---

综上，基本XML的操作就如此了。下面是整合所有的代码，可以直接运行的，前提是在src下自己配好Xml文件。

XML

 <?xml version="1.0" encoding="UTF-8" standalone="no"?><father>
     <son id="001">
         <name>老大</name>
         <age>27</age>
     </son>
     <son id="002">
         <name>老二</name>
         <age>13</age>
     </son>
     <son id="003">
         <name>老三</name>
         <age>13</age>
     </son>
 </father>

xmlManage.java

 package xmlManger;

 import java.io.File;

 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 javax.xml.xpath.XPath;
 import javax.xml.xpath.XPathConstants;
 import javax.xml.xpath.XPathExpressionException;
 import javax.xml.xpath.XPathFactory;

 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;

 public class xmlManage {

     private static String xmlPath = "E:\\Eclipse(Plugin)\\workspace\\xmlManger\\src\\family.xml";

     public static void getFamilyMemebers(){
         DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
         dbf.setIgnoringElementContentWhitespace(true);
         try {
             DocumentBuilder db = dbf.newDocumentBuilder();
             Document doc = db.parse(xmlPath); // 使用dom解析xml文件

             NodeList sonlist = doc.getElementsByTagName("son");
             for (int i = 0; i < sonlist.getLength(); i++) // 循环处理对象
             {
                 Element son = (Element)sonlist.item(i);;

                 for (Node node = son.getFirstChild(); node != null; node = node.getNextSibling()){
                     if (node.getNodeType() == Node.ELEMENT_NODE){
                         String name = node.getNodeName();
                         String value = node.getFirstChild().getNodeValue();
                         System.out.println(name+" : "+value);
                     }
                 }
             }
         } catch (Exception e) {
             e.printStackTrace();
         }
     }

     public static void modifySon(){
         DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
         dbf.setIgnoringElementContentWhitespace(true);
         try{

             DocumentBuilder db=dbf.newDocumentBuilder();
             Document xmldoc=db.parse(xmlPath);

             Element root = xmldoc.getDocumentElement();

             Element per =(Element) selectSingleNode("/father/son[@id='001']", root);
             per.getElementsByTagName("age").item(0).setTextContent("27");

             TransformerFactory factory = TransformerFactory.newInstance();
             Transformer former = factory.newTransformer();
             former.transform(new DOMSource(xmldoc), new StreamResult(new File(xmlPath)));
         }catch(Exception e){
             e.printStackTrace();
         }
     }

     public static void discardSon(){

         DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
         dbf.setIgnoringElementContentWhitespace(true);

         try{

             DocumentBuilder db=dbf.newDocumentBuilder();
             Document xmldoc=db.parse(xmlPath);

             Element root = xmldoc.getDocumentElement();

             Element son =(Element) selectSingleNode("/father/son[@id='002']", root);
             root.removeChild(son);

             TransformerFactory factory = TransformerFactory.newInstance();
             Transformer former = factory.newTransformer();
             former.transform(new DOMSource(xmldoc), new StreamResult(new File(xmlPath)));

         }catch(Exception e){
             e.printStackTrace();
         }
     }

     public static void createSon() {
         DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
         dbf.setIgnoringElementContentWhitespace(false);

         try{

             DocumentBuilder db=dbf.newDocumentBuilder();
             Document xmldoc=db.parse(xmlPath);

             Element root = xmldoc.getDocumentElement();

             //删除指定节点

             Element son =xmldoc.createElement("son");
             son.setAttribute("id", "004");

             Element name = xmldoc.createElement("name");
             name.setTextContent("小儿子");
             son.appendChild(name);

             Element age = xmldoc.createElement("name");
             age.setTextContent("0");
             son.appendChild(age);

             root.appendChild(son);
             //保存
             TransformerFactory factory = TransformerFactory.newInstance();
             Transformer former = factory.newTransformer();
             former.transform(new DOMSource(xmldoc), new StreamResult(new File(xmlPath)));

         }catch(Exception e){
             e.printStackTrace();
         }
     }

     public static Node selectSingleNode(String express, Element source) {
         Node result=null;
         XPathFactory xpathFactory=XPathFactory.newInstance();
         XPath xpath=xpathFactory.newXPath();
         try {
             result=(Node) xpath.evaluate(express, source, XPathConstants.NODE);
         } catch (XPathExpressionException e) {
             e.printStackTrace();
         }

         return result;
     }

     public static void main(String[] args){
         getFamilyMemebers();
         System.out.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
         modifySon();
         System.out.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
         getFamilyMemebers();
         System.out.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
         discardSon();
         System.out.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
         getFamilyMemebers();
         System.out.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
         createSon();
         System.out.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
         getFamilyMemebers();
     }
 }

运行结果：