java对xml进行查询操作代码

(2008-07-29 13:15:00)

标签：

it

test.java

----------

package com.shao;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import org.w3c.dom.*;

import org.xml.sax.SAXException;

import javax.xml.parsers.*;

import javax.xml.transform.*;

import javax.xml.transform.dom.DOMSource;

import javax.xml.transform.stream.*;

import javax.xml.xpath.*;

public class Test {

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();

Document xmldoc = db.parse(new

File("src/com/shao/test1.xml"));

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("/books/book[name='哈里波特']",

root);

System.out.println("--- 查询找《哈里波特》 ----");

output(theBook);

// --- 此时修改这本书的价格 -----

theBook.getElementsByTagName_r("price").item(0).setTextContent("15");//

getElementsByTagName返回的是NodeList，所以要跟上item(0)

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 ----

theBook.setAttribute("id", "B01");

theBook.setAttribute("pId","1");

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("/books/book[@id='B02']",

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("src/com/shao/test2.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 (XPathExpressionExceptione) {

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 (XPathExpressionExceptione) {

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();

}

}

}

xml文件

encoding="UTF-8"?>

哈里波特

10

这是一本很好看的书。

三国演义

10

四大名著之一。

水浒

6

四大名著之一。

红楼

5

四大名著之一。

分享：

喜欢

0

赠金笔

加载中，请稍候......

评论加载中，请稍候...

发评论

登录名： 密码： 找回密码 注册记住登录状态

昵   称：

评论并转载此博文

发评论

以上网友发言只代表其个人观点，不代表新浪网的观点或立场。