我是学习XSD的新手.我编写了一个XSD文件和XML文件,以及一个程序来针对XSD验证XML.当我运行程序时,出现错误消息,指出从元素“ id”开始发现无效内容.预期为“ {id}”之一.有人可以解释我要去哪里了.

XSD文件：

和XML文件：

    

       1234
       Pradeep
       Sanskrit
       Beginner
    

验证XML文件的Java程序：

import java.io.File;
import java.io.IOException;

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.SAXException;

public class ValidatorDemo {

    public static void main(String[] args) {

      System.out.println("student.xml validates against studentRule.xsd? "+validateXMLSchema("studentRule.xsd", "student.xml"));

      }

    public static boolean validateXMLSchema(String xsdPath, String xmlPath){

        try {
            SchemaFactory factory = 
                    SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
            Schema schema = factory.newSchema(new File(xsdPath));
            Validator validator = schema.newValidator();
            validator.validate(new StreamSource(new File(xmlPath)));
        } catch (IOException | SAXException e) {
            System.out.println("Exception: "+e.getMessage());
            return false;
        }
        return true;
    }
}