dom处理配置文件_待完善

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Scanner;

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 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;
import org.xml.sax.SAXException;

public class DomSync {
public static void main(String[] args) {
DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();
Element theBook=null, theElem=null, root=null;
try {
factory.setIgnoringElementContentWhitespace(true);

DocumentBuilder db=factory.newDocumentBuilder();

Scanner scan = new Scanner(System.in);
System.out.println("输入文件路径");
StringBuffer sb = new StringBuffer();
Scanner in = new Scanner(System.in);
String next = null;
do {
next = in.next();
sb.append(next);
} while (!next.equals("end") );
in.close();
Document xmldoc=db.parse(new File(sb.toString().replaceAll("end", "")));
root=xmldoc.getDocumentElement();

//--- 新建一本书开始 ----
// theBook=xmldoc.createElement("book");
// theElem=xmldoc.createElement("name");
// theElem.setTextContent("新书");
// theBook.appendChild(theElem);
//
// theElem=xmldoc.createElement("price");
// theElem.setTextContent("20");
// theBook.appendChild(theElem);
//
// theElem=xmldoc.createElement("memo");
// theElem.setTextContent("新书的更好看。");
// theBook.appendChild(theElem);
// root.appendChild(theBook);
// System.out.println("--- 新建一本书开始 ----");
// output(xmldoc);
//--- 新建一本书完成 ----

//--- 下面对《哈里波特》做一些修改。 ----
//--- 查询找《哈里波特》----
theBook=(Element) selectSingleNode("/l2vpn/vpwsinstances/vpwsinstance", root);
System.out.println("--- 查询找《vpwsinstance》 ----");
output(theBook);
//--- 此时修改这本书的价格 -----
// theBook.getElementsByTagName("price").item(0).setTextContent("15");//getElementsByTagName返回的是NodeList，所以要跟上item(0)。另外，getElementsByTagName("price")相当于xpath的".//price"。
// System.out.println("--- 此时修改这本书的价格 ----");
// output(theBook);
//--- 另外还想加一个属性id，值为B01 ----
Element newattr = xmldoc.createElement("description");
// Text t = xmldoc.createTextNode("<description/>");
// newattr.set
// newattr.appendChild(t);
theBook.appendChild(newattr);
System.out.println("--- 另外还想加一个属性id，值为B01 ----");
output(theBook);
//--- 对《哈里波特》修改完成。 ----

//--- 要用id属性删除《三国演义》这本书 ----
// theBook=(Element) selectSingleNode("/l2vpn/vpwsinstances/vpwsinstance/instancename", root);
// System.out.println("--- 要用id属性删除《三国演义》这本书 ----");
// output(theBook);
// theBook.getParentNode().removeChild(theBook);
// System.out.println("--- 删除后的ＸＭＬ ----");
// output(xmldoc);

//--- 再将所有价格低于10的书删除 ----
// NodeList someBooks=selectNodes("/books/book[price<10]", root);
// System.out.println("--- 再将所有价格低于10的书删除 ---");
// System.out.println("--- 符合条件的书有　"+someBooks.getLength()+"本。 ---");
// for(int i=0;i<someBooks.getLength();i++) {
// someBooks.item(i).getParentNode().removeChild(someBooks.item(i));
// }
// output(xmldoc);

saveXml("l2vpn.xml", xmldoc);
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}

public static void output(Node node) {//将node的XML字符串输出到控制台
TransformerFactory transFactory=TransformerFactory.newInstance();
try {
Transformer transformer = transFactory.newTransformer();
transformer.setOutputProperty("encoding", "gb2312");
transformer.setOutputProperty("indent", "yes");

DOMSource source=new DOMSource();
source.setNode(node);
StreamResult result=new StreamResult();
result.setOutputStream(System.out);

transformer.transform(source, result);
} catch (TransformerConfigurationException e) {
e.printStackTrace();
} catch (TransformerException e) {
e.printStackTrace();
}
}

public static Node selectSingleNode(String express, Object source) {//查找节点，并返回第一个符合条件节点
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 NodeList selectNodes(String express, Object source) {//查找节点，返回符合条件的节点集。
NodeList result=null;
XPathFactory xpathFactory=XPathFactory.newInstance();
XPath xpath=xpathFactory.newXPath();
try {
result=(NodeList) xpath.evaluate(express, source, XPathConstants.NODESET);
} catch (XPathExpressionException e) {
e.printStackTrace();
}

return result;
}

public static void saveXml(String fileName, Document doc) {//将Document输出到文件
TransformerFactory transFactory=TransformerFactory.newInstance();
try {
Transformer transformer = transFactory.newTransformer();
transformer.setOutputProperty("indent", "yes");

DOMSource source=new DOMSource();
source.setNode(doc);
StreamResult result=new StreamResult();
result.setOutputStream(new FileOutputStream(fileName));

transformer.transform(source, result);
} catch (TransformerConfigurationException e) {
e.printStackTrace();
} catch (TransformerException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}

http://blog.csdn.net/smildlzj/article/details/1548713