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>