java读取Xml，写入Xml的简单Dom操作，忽略DTD验证

package com.yd.common;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileWriter;
import java.io.PrintWriter;
import java.io.StringWriter;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import com.sun.org.apache.xml.internal.serialize.OutputFormat;
import com.sun.org.apache.xml.internal.serialize.XMLSerializer;

public class UpdateXml {

private void doc2XmlFile(Document document, String filePath) {
try {
OutputFormat format = new OutputFormat(document);//Serialize DOM
format.setEncoding("UTF-8");
StringWriter stringOut = new StringWriter();//Writer will be a String
XMLSerializer serial = new XMLSerializer(stringOut, format);
serial.asDOMSerializer();// As a DOM Serializer
serial.serialize(document.getDocumentElement());
String STRXML = stringOut.toString(); //Spit out DOM as a String
File f = new File(filePath);
PrintWriter out = new PrintWriter(new FileWriter(f));
out.print(STRXML + "\n");
out.close();
} catch (Exception ex) {
ex.printStackTrace();
}
}

private Document load(String filename) {
Document document = null;
try {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setValidating(false);
DocumentBuilder builder = factory.newDocumentBuilder();
builder.setEntityResolver(this.new IgnoreDTDEntityResolver());
document = builder.parse(new File(filename));
document.normalize();
} catch (Exception ex) {
ex.printStackTrace();
}
return document;
}

/**
* 演示修改文件的具体某个节点的值
*/
public void xmlUpdateDemo(String filePath, String customerName, String DMSID) {
Document document = load(filePath);
Element root = document.getDocumentElement();
/** 如果root有子元素 */
if (root.hasChildNodes()) {
/** ftpnodes */
NodeList ftpnodes = root.getChildNodes();

/** 循环取得ftp所有节点 */
for (int i = 0; i < ftpnodes.getLength(); i++) {
Node subnode = ftpnodes.item(i);

if (subnode.getNodeType() == Node.ELEMENT_NODE && subnode.getNodeName() == "Details") {
subnode.getAttributes().getNamedItem("DMSID").setNodeValue(DMSID);
}
if (subnode.getNodeType() == Node.ELEMENT_NODE && subnode.getNodeName() == "CustomerDetails") {
subnode.getAttributes().getNamedItem("CustomerName").setNodeValue(customerName);
}
}
}
doc2XmlFile(document, filePath);
}
/**
* 忽略DTD验证文件子类
*/
class IgnoreDTDEntityResolver implements EntityResolver{
public InputSource resolveEntity(java.lang.String publicId, java.lang.String systemId) throws SAXException,
java.io.IOException{
if (systemId.contains("NOCServerDetails.dtd")){
InputSource is = new InputSource(new ByteArrayInputStream("<?xml version=\"1.0\" encoding=\"UTF-8\"?>".getBytes()));
return is;
}
else
return null;
}
}

public static void main(String args[]) throws Exception {
new UpdateXml().xmlUpdateDemo("C:\\testop_Key\\NOCServerDetails.xml","3333","3333");

}
}