编程实现DTD规范对XML文件内容正确性的校验
1.User.dtd
<!ELEMENT User (name+,gender,birthday,address,job_time,curr_postion,email,mobilephone+,curr_salary?,hope_salary,personal_price?)><!ATTLIST basic-information title CDATA #REQUIRED><!ELEMENT name (#PCDATA)><!ELEMENT gender EMPTY><!ATTLIST gender value (female|male) #REQUIRED><!ELEMENT birthday (#PCDATA)><!ELEMENT address (#PCDATA)><!ELEMENT job_time (#PCDATA)><!ELEMENT curr_postion (#PCDATA)><!ELEMENT email (#PCDATA)><!ELEMENT mobilephone (#PCDATA)><!ELEMENT curr_salary (#PCDATA)><!ELEMENT hope_salary (#PCDATA)><!ELEMENT personal_price (#PCDATA)><!ENTITY personal "hello Daniel! You are a good Software Engineer!">
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2.User.xml
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<?xml version="1.0" encoding="GBK"?><!DOCTYPE User SYSTEM "User.dtd"><User> <name>Daniel Cheng</name> <gender value="male"/> <birthday>1985/01/08</birthday> <address>北京市朝阳区东三环中路CBD</address> <!--这个注释去掉的话，你将会发现DTD校验XML报告错误,因为DTD文件里根本没有定义hobby元素 <hobby>Swimming,Basketball!</hobby> --> <job_time>1</job_time> <curr_postion>Software Engineer</curr_postion> <email>mingdongcheng@163.com</email> <mobilephone>15201010100</mobilephone> <curr_salary/> <hope_salary>10万-30万</hope_salary> <personal_price> 自我评价: &personal; </personal_price></User>
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3.UserXMLValidateDTD.java
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package exercise;import java.io.File;import java.io.IOException;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;import javax.xml.parsers.ParserConfigurationException;import org.xml.sax.SAXException;import org.xml.sax.SAXParseException;import org.xml.sax.helpers.DefaultHandler;/** * 用DTD规范校验XML文件内容的正确性 * @author Daniel Cheng * */public class UserXMLValidateDTD { private boolean validate = true; public UserXMLValidateDTD() { } public boolean XMLValidateDTD(File file) { DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); factory.setValidating(true); try { DocumentBuilder builder = factory.newDocumentBuilder(); MyHandler mh = new MyHandler(); builder.setErrorHandler(mh); builder.parse(file); } catch (ParserConfigurationException e) { e.printStackTrace(); } catch (SAXException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return validate; } class MyHandler extends DefaultHandler { String errorMessage = null; public void error(SAXParseException e) throws SAXException { errorMessage = e.getMessage(); System.out.println("一般错误！！！" + errorMessage); validate = false; } public void fatalError(SAXParseException e) throws SAXException { errorMessage = e.getMessage(); System.out.println("严重错误！！！" + errorMessage); validate = false; } }}?
?4.UserDomParser.java
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package exercise;import java.io.File;import java.io.IOException;import java.util.Scanner;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;import javax.xml.parsers.ParserConfigurationException;import org.w3c.dom.Attr;import org.w3c.dom.Document;import org.w3c.dom.Element;import org.w3c.dom.NamedNodeMap;import org.w3c.dom.Node;import org.w3c.dom.NodeList;import org.xml.sax.SAXException;/** * 用DTD检验XML并解析 * @author Daniel Cheng * */public class UserDomParser { public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException { DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); String fileName = ""; File file = null; Scanner sc = new Scanner(System.in); while (true) { if (fileName.equals("")) { System.out.println("请输入xml文件名字："); fileName = sc.nextLine(); } file = new File(fileName); if (!file.exists()) { System.out.println("xml文件不存在！"); fileName = ""; continue; } else { break; } } boolean validate = new UserXMLValidateDTD().XMLValidateDTD(file); if (validate) { System.out.println("通过DTD校验！"); Document doc = builder.parse(file); Element root = doc.getDocumentElement(); printElement(root); } else { System.out.println("该XML文件未通过DTD校验解析终止！！！"); } } public static void printElement(Element e) { System.out.print("<" + e.getTagName()); NamedNodeMap map = e.getAttributes(); for (int i = 0; i < map.getLength(); i++) { Attr attr = (Attr) map.item(i); System.out.print(" " + attr.getName() + "="" + attr.getValue() + """); } System.out.print(">"); NodeList list = e.getChildNodes(); for (int i = 0; i < list.getLength(); i++) { Node n = list.item(i); if (n.getNodeType() == Node.ELEMENT_NODE) { Element en = (Element) n; printElement(en); } else { System.out.println(n.getTextContent()); } } System.out.print("</" + e.getTagName() + ">"); }}?