問題描述

我需要一些代碼示例來展示如何根據(jù)架構(gòu)驗證 xml 文件.下面是我的 XML 文檔:

I need some code sample which shows how I can validate a xml file against a schema. Below is my XML document:

<birthdate>
    <month>January</month>
    <day>21</day>
    <year>1983</year>
</birthdate>

我要驗證上述 XML 的架構(gòu)是:

The schema against which I want to validate the above XML is:

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:import namespace="http://www.w3.org/XML/1998/namespace"
        schemaLocation="http://www.w3.org/2001/xml.xsd" />

  <xs:element name="birthdate">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="month" type="xs:string" />
        <xs:element name="day" type="xs:int" />
        <xs:element name="year" type="xs:int" />
      </xs:sequence>  
    </xs:complexType>
  </xs:element>
</xs:schema>

現(xiàn)在有人可以幫我編寫 Java 代碼，如果 XML 文檔按照我指定的模式有效，則該代碼將這些作為輸入并給出正確的輸出?

Now can some one help me write the Java code that will take these as input and give proper output if the XML doc is a valid as per the schema I specified?

現(xiàn)在我在理解下面的代碼時遇到了問題，比如 MySAXHandler 上的方法是如何被調(diào)用的，因為類沒有被實例化并且方法沒有被顯式調(diào)用.誰能解釋一下?還有有什么方法可以直接傳遞文件而不是通過字符串傳遞.

Now i have issue understanding the below code like how the methods on MySAXHandler are getting calling becoz the class is not instantiated and methods are not called explicitely. Can anyone explain? And also is there any way i can pass the files direcly instead of passing through Strings.

代碼是 -

import java.io.StringReader;

import javax.xml.XMLConstants;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.transform.sax.SAXSource;
import javax.xml.validation.SchemaFactory;

import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.helpers.DefaultHandler;

public class XMLval {
  public static void main(String args[])throws Exception {
    SAXParserFactory spf = SAXParserFactory.newInstance();
    SAXParser parser = null;
    spf.setNamespaceAware(true);
    try {
     SchemaFactory sf =
                     SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI); 
     spf.setSchema(sf.newSchema(new SAXSource(new InputSource(new StringReader(schemaString)))));
 parser = spf.newSAXParser();
}
catch(SAXException e) {
  e.printStackTrace(System.err);
  System.exit(1);    
} 
catch(ParserConfigurationException e) {
  e.printStackTrace(System.err);
  System.exit(1);    
}
MySAXHandler handler = new MySAXHandler(); 
System.out.println(schemaString);
parser.parse(new InputSource(new StringReader(xmlString)), handler);


}



static String xmlString = "<?xml version="1.0"?>" +
  "<birthdate>" +
  "<month>January</month>" +
  "<day>21</day>" +
  "<year>1983</year>" +
  "</birthdate>";



static String schemaString ="<?xml version="1.0" encoding="UTF-8"?>" +

  "<xs:element name="birthdate">" +
  "<xs:complexType>" +
  "<xs:sequence>" +
  "<xs:element name="month" type="xs:string"/>" +
  "<xs:element name="day" type="xs:int"/>" +
  "<xs:element name="year" type="xs:int" />" +
  "</xs:sequence>" +
                  "</xs:complexType>" +
                  "</xs:element>" +
                  "</xs:schema>";
}

class MySAXHandler extends DefaultHandler {
  public void startDocument() {
    System.out.println("Start document: ");
  }    
    public void endDocument()  {
    System.out.println("End document: ");
  }

  public void startElement(String uri, String localName, String qname, 
                                                               Attributes attr)
  {
    System.out.println("Start element: local name: " + localName + " qname: " 
                                                        + qname + " uri: "+uri);
    int attrCount = attr.getLength();
    if(attrCount>0) {
      System.out.println("Attributes:"); 
      for(int i = 0 ; i<attrCount ; i++) {
        System.out.println("  Name : " + attr.getQName(i)); 
        System.out.println("  Type : " + attr.getType(i)); 
        System.out.println("  Value: " + attr.getValue(i)); 
      }
    } 
  }

  public void endElement(String uri, String localName, String qname) {
    System.out.println("End element: local name: " + localName + " qname: "
                                                         + qname + " uri: "+uri);
  }

  public void characters(char[] ch, int start, int length) {
    System.out.println("Characters: " + new String(ch, start, length));
  }
}

推薦答案

你可以試試JDOM庫.

You can try JDOM library.

http://www.jdom.org/docs/faq.html#a0360

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