DocumentBuilderFactory setSchema() Method

Description

The Javax.xml.parsers.DocumentBuilderFactory.setSchema(Schema schema) method Set the Schema to be used by parsers created from this factory.

When a Schema is non-null, a parser will use a validator created from it to validate documents before it passes information down to the application.

When errors are found by the validator, the parser is responsible to report them to the user-specified ErrorHandler (or if the error handler is not set, ignore them or throw them), just like any other errors found by the parser itself. In other words, if the user-specified ErrorHandler is set, it must receive those errors, and if not, they must be treated according to the implementation specific default error handling rules.

A validator may modify the outcome of a parse (for example by adding default values that were missing in documents), and a parser is responsible to make sure that the application will receive modified DOM trees.

Declaration

Following is the declaration for Javax.xml.parsers.DocumentBuilderFactory.setSchema() method

public void setSchema(Schema schema)

Parameters

schema − Schema to use or null to remove a schema.

Return Value

This method does not return a value.

Exception

UnsupportedOperationException − When implementation does not override this method.

Example

The schema set in this example is a file called Student.xsd and is in our CLASSPATH. The contents of this file are the following −

<?xml version = "1.0" encoding = "utf-8"?>
<xs:schema attributeFormDefault = "unqualified" elementFormDefault = "qualified" xmlns:xs = "http://www.w3.org/2001/XMLSchema">
   <xs:element name = "student">
      <xs:complexType>
         <xs:sequence>
            <xs:element name = "age" type = "xs:unsignedByte" />
            <xs:element name = "name" type = "xs:string" />
         </xs:sequence>
         <xs:attribute name = "id" type = "xs:unsignedByte" use = "required" />
      </xs:complexType>
   </xs:element>
</xs:schema>

The following example shows the usage of Javax.xml.parsers.DocumentBuilderFactory.setSchema() method.

package com.tutorialspoint;

import java.io.File;
import javax.xml.XMLConstants;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;

public class DocumentBuilderFactoryDemo {

   public static void main(String[] args) {

      // create a new DocumentBuilderFactory
      DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
      try {
         File file = new File("Student.xsd");

         // create schema
         String constant = XMLConstants.W3C_XML_SCHEMA_NS_URI;
         SchemaFactory xsdFactory = SchemaFactory.newInstance(constant);
         Schema schema = xsdFactory.newSchema(file);
         
         // set schema
         factory.setSchema(schema);

         // get the schema
         System.out.println("" + factory.getSchema());

      } catch (Exception ex) {
         ex.printStackTrace();
      }

   }
}

If we compile the code and execute it, this will produce the following result −

com.sun.org.apache.xerces.internal.jaxp.validation.SimpleXMLSchema@2c091cee