java DOM 操作xml

1 代码如下：

 package dom.pasing;

 import java.io.IOException;
 import java.io.StringWriter;

 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.TransformerException;
 import javax.xml.transform.TransformerFactory;
 import javax.xml.transform.dom.DOMSource;
 import javax.xml.transform.stream.StreamResult;

 import org.apache.xml.serialize.OutputFormat;
 import org.apache.xml.serialize.XMLSerializer;
 import org.w3c.dom.Attr;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;
 import org.w3c.dom.Text;

 public class DOMTest {

     /**
      *
      * @return
      */
     public static Document createDocument()  {

         Document document = null;

         try {
             DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
             DocumentBuilder builder = builderFactory.newDocumentBuilder();
             document = builder.newDocument();
             Element root = document.createElement("students");
             document.appendChild(root);

             /**
              *     <students>
              *         <student sn="01">
              *             <name>张三</name>
              *             <age>19</age>
              *         </student>
              *     </students>
              */
             Element stuEle = document.createElement("student");

             Attr attr = document.createAttribute("sn");
             attr.setValue("01");
             stuEle.setAttributeNode(attr);

             Element nameElem = document.createElement("name");
             Text txtName = document.createTextNode("张三");
             nameElem.appendChild(txtName);
             stuEle.appendChild(nameElem);

             Element ageElem = document.createElement("age");
             Text txtAge = document.createTextNode("19");
             ageElem.appendChild(txtAge);
             stuEle.appendChild(ageElem);
             document.getDocumentElement().appendChild(stuEle); //在文档根元素节点studnets下，添加一个student元素节点

             /**
              * 创建节点
              *     <student>
              *         <name>李四</name>
              *         <age>24</age>
              *     </student>
              */
             Element stuEle2 = document.createElement("student");

             Attr attr2 = document.createAttribute("sn");
             attr2.setValue("02");
             stuEle2.setAttributeNode(attr2);

             Element nameEle2 = document.createElement("name");
             Text txtName2 = document.createTextNode("李四");
             nameEle2.appendChild(txtName2);
             stuEle2.appendChild(nameEle2);

             Element ageEle2 = document.createElement("age");
             Text txtAge2 = document.createTextNode("24");
             ageEle2.appendChild(txtAge2);
             stuEle2.appendChild(ageEle2);
             document.getDocumentElement().appendChild(stuEle2); //在文档根元素节点studnets下，添加一个student元素节点
         } catch (ParserConfigurationException e) {
             e.printStackTrace();
         }

         return document;
     }

     public static void alterDocument(Document document) {
         NodeList nodeList = document.getElementsByTagName("student");
         Node node = nodeList.item(0);
         node.getParentNode().removeChild(node); //移除第1个student元素节点
     }

     /**
      *  转换DOM为String
      * @param document
      * @return
      * @throws TransformerException
      */
     public static String documentToStr(Document document) {

         String result = null;

         try {
             DOMSource source = new DOMSource(document);
             StringWriter stringWriter = new StringWriter();
             StreamResult streamResult = new StreamResult(stringWriter);

             TransformerFactory transformerFactory = TransformerFactory.newInstance();
             Transformer transformer = transformerFactory.newTransformer();
             transformer.setOutputProperty(OutputKeys.INDENT, "yes");     //默认的缩进量长度为0
             transformer.setOutputProperty(OutputKeys.ENCODING, "utf-8");
             transformer.transform(source, streamResult);

             result = stringWriter.toString();
         } catch (TransformerException e) {
             e.printStackTrace();
         }
         return result;
     }

     /**
      *
      * @param document
      * @return
      */
     public static String documentToIndentStr(Document document) {

         String result = null;

         try {

             StringWriter stringWriter = new StringWriter();

             OutputFormat format = new OutputFormat(document);
             format.setLineWidth(100);
             format.setIndenting(true);
             format.setIndent(4);

             XMLSerializer serializer = new XMLSerializer(stringWriter, format);
             serializer.serialize(document);

             result = stringWriter.toString();
         } catch (IOException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
         return result;
     }    

     public static void main(String[] args) {

         String rslt = null;

         Document document = createDocument();

         rslt = documentToIndentStr(document);

         System.out.println(rslt);
     }
 }

输出结果：

<?xml version="1.0" encoding="UTF-8"?>
<students>
　　<student sn="01">
　　　　<name>张三</name>
　　　　<age>19</age>
　　</student>
　　<student sn="02">
　　　　<name>李四</name>
　　　　<age>24</age>
　　</student>
</students>