java中实现xml schema 验证文件

XML 是可扩展标记语言，也就是说其中的标记我们可以按照我们的意愿生成，只要符合语法规则就认为是合法的。

但是很多情况下我们需要根据一定的验证规则对xml 文档实施限制。当我们书写一个xml 文档的时候，通过验证文档对其进行验证，可以保证所书写的文档是合法合理的。这样我们的程序才可以对其进行适当的操作。不然随意写一个符合语法的xml 文档，我们的程序显然不能总是能对其进行操作。

验证文档对所书写的xml 文档进行合理合法的验证，验证文档有两种格式，一种为dtd ，一种为xsd （schema 形式）。

Xsd 文档主要起一个验证作用!

我们可以在操作一个传输过来的，或者新生成的xml 文档先进行验证，然后再进行解析，这样可以保证操作成功。

在此，我们使用schema 格式的文档对xml 进行验证。

<? xml version = "1.0" encoding = "UTF-8" ?>

<!--W3C Schema generated by XMLSpy v2008 (http://www.altova.com)-->

< xs:schema xmlns = "http://www.frank.com"

xmlns:xs = "http://www.w3.org/2001/XMLSchema" targetNamespace = "http://www.frank.com" elementFormDefault = "qualified" >

  < xs:element name = "students" >

  < xs:complexType >

   < xs:sequence >

    < xs:element ref = "student" maxOccurs = "unbounded" />

   </ xs:sequence >

  </ xs:complexType >

  </ xs:element >

  < xs:element name = "student" >

  < xs:complexType >

   < xs:sequence >

    < xs:element ref = "name" />

    < xs:element ref = "age" />

   </ xs:sequence >

  </ xs:complexType >

  </ xs:element >

  < xs:element name = "name" type = "xs:string" />

  < xs:element name = "age" type = "xs:byte" />

</ xs:schema >

 

 

<? xml version = "1.0" encoding = "UTF-8" ?>

< my:students xmlns:my = "http://www.frank.com" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" >

  < my:student >

  < my:name > tom </ my:name >

  < my:age > 23 </ my:age >

  </ my:student >

  < my:student >

  < my:name > mike </ my:name >

  < my:age > 23 </ my:age >

  </ my:student >

</ my:students >

 

package test;

 

import java.io.File;

import java.io.IOException;

import java.net.URL;

 

import javax.xml.transform.Source;

import javax.xml.transform.stream.StreamSource;

import javax.xml.validation.Schema;

import javax.xml.validation.SchemaFactory;

import javax.xml.validation.Validator;

 

import org.xml.sax.SAXException;

 

public class TestXML {

 

    /**

      * @param args

      */

    public static void main(String[] args) throws SAXException, IOException {

       // 建立 schema 工厂

       SchemaFactory schemaFactory = SchemaFactory.newInstance("http://www.w3.org/2001/XMLSchema");

       // 建立验证文档文件对象，利用此文件对象所封装的文件进行 schema 验证

       File schemaFile = new File("C:/Documents and Settings/pengch/workspace/xmlschema/test/students.xsd");

       // 利用 schema 工厂，接收验证文档文件对象生成 Schema 对象

       Schema schema = schemaFactory.newSchema(schemaFile);

       // 通过 Schema 产生针对于此 Schema 的验证器，利用 students.xsd 进行验证

       Validator validator = schema.newValidator();

       // 得到验证的数据源，就是 students.xml

       Source source = new StreamSource("C:/Documents and Settings/pengch/workspace/xmlschema/test/students.xml");

       // 开始验证，成功输出 success!!! ，失败输出 fail

       try {

           validator.validate(source);

           System.out.println("success!!!");

       } catch (Exception ex) {

           System.out.println("fail");

       }

 

    }

    }

 

抽象一下：

 

 

 

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.xml.sax.ErrorHandler;

import org.xml.sax.SAXException;

import org.xml.sax.SAXParseException;

 

public class DefaultErrorHandler implements ErrorHandler {

 

    protected static Log logger = LogFactory.getLog(DefaultErrorHandler.class);

   

    public void error(SAXParseException exception) throws SAXException {

    if(logger.isErrorEnabled()) {

        logger.error("XML file is invalid", exception);

    }

   

    throw new SAXException(exception);

    }

 

    public void fatalError(SAXParseException exception) throws SAXException {

    if(logger.isErrorEnabled()) {

        logger.error("XML file is invalid", exception);

    }

   

    throw new SAXException(exception);

    }

 

    public void warning(SAXParseException exception) throws SAXException {

    if(logger.isWarnEnabled()) {

        logger.warn("Warning", exception);

    }

    exception.printStackTrace();

    }

}

 

 

import java.io.IOException;

import java.io.InputStream;

 

import javax.xml.XMLConstants;

import javax.xml.transform.stream.StreamSource;

import javax.xml.validation.Schema;

import javax.xml.validation.SchemaFactory;

import javax.xml.validation.Validator;

 

import org.xml.sax.ErrorHandler;

import org.xml.sax.SAXException;

 

 

public class DefaultSchemaValidator extends SchemaValidator {

 

    private InputStream schemaStream;

   

    /**

     * 构造函数

     * @param schemaStream schema 文件输入流

     */

    public DefaultSchemaValidator(InputStream schemaStream) {

    this.schemaStream = schemaStream;

    }

   

    /**

     * 构造函数

     * @param clz

     * @param schemaFile schema 文件

     */

    public DefaultSchemaValidator(Class clz, String schemaFile) {

    this.schemaStream = clz.getResourceAsStream(schemaFile);

    }

   

    public DefaultSchemaValidator(ClassLoader classLoader, String schemaFile) {

    this.schemaStream = classLoader.getResourceAsStream(schemaFile);

    }

   

    public void validate(InputStream xmlStream, ErrorHandler errorHandler) throws SAXException, IOException {

    Schema schema = createSchema(schemaStream);

    Validator validator = schema.newValidator();

    validator.setErrorHandler(errorHandler);

    validator.validate(new StreamSource(xmlStream));

    }

   

    /**

         * 验证给定的 xml 是否合法

         *

         * @return

         * @throws SAXException

         */

    protected Schema createSchema(InputStream schemaStream) throws SAXException {

    SchemaFactory schemaFactory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);

    return schemaFactory.newSchema(new StreamSource(schemaStream));

    }

}

 

import java.io.IOException;

import java.io.InputStream;

 

import org.xml.sax.ErrorHandler;

import org.xml.sax.SAXException;

 

 

public abstract class SchemaValidator {

    public abstract void validate(InputStream xmlStream, ErrorHandler errorHandler) throws SAXException, IOException;

    public void validate(InputStream xmlStream) throws SAXException, IOException {

    validate(xmlStream, new DefaultErrorHandler());

    }

}

 

 

 

import java.io.IOException;

 

import org.xml.sax.SAXException;

 

import com.DefaultSchemaValidator;

import com.SchemaValidator;

 

public class TestXML2 {

 

    /**

      * @param args

      */

    public static void main(String[] args) {

       // TODO Auto-generated method stub

       SchemaValidator schemaValidator=   new DefaultSchemaValidator(TestXML2.class,"Students.xsd");

       try {

           schemaValidator.validate(TestXML2.class.getResourceAsStream("students.xml"));

       } catch (SAXException e) {

           // TODO Auto-generated catch block

           e.printStackTrace();

       } catch (IOException e) {

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