Javax.xml.bind.JAXBContext.generateSchema() Method

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Description

The Javax.xml.bind.JAXBContext.generateSchema(SchemaOutputResolver outputResolver) method generates the schema documents for this context.

Declaration

Following is the declaration for javax.xml.bind.JAXBContext.generateSchema(SchemaOutputResolver outputResolver) method

public void generateSchema(SchemaOutputResolver outputResolver)

Parameters

outputResolver − This object controls the output to which schemas will be sent.

Return Value

The method does not return any value.

Exception

• IOException − if SchemaOutputResolver throws an IOException.

• UnsupportedOperationException − Calling this method on JAXB 1.0 implementations will throw an UnsupportedOperationException.

Example

The following example shows the usage of javax.xml.bind.JAXBContext.generateSchema(SchemaOutputResolver outputResolver) method. To proceed, consider the following Student class which will be used to have objects for marshalling purpose −

package com.tutorialspoint;

import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
 
@XmlRootElement
public class Student{
 
   String name;
   int age;
   int id;

   public String getName(){
      return name;
   }

   @XmlElement
   public void setName(String name){
      this.name = name;
   }

   public int getAge(){
      return age;
   }

   @XmlElement
   public void setAge(int age){
      this.age = age;
   }

   public int getId(){
      return id;
   }

   @XmlAttribute
   public void setId(int id){
      this.id = id;
   }
}

The program below generates XSD from the Student.java class.

package com.tutorialspoint;

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

import javax.xml.bind.JAXBContext;
import javax.xml.bind.SchemaOutputResolver;

public class JAXBContextDemo {
   public static void main(String[] args) throws IOException {
      FileInputStream fis = null;
      try {
         // create new JAXB context
         JAXBContext context = JAXBContext.newInstance(Student.class);
         
         // create new schema out put resolver
         SchemaOutputResolver sor = new DemoSchemaOutputResolver();
         
         // generate schema
         context.generateSchema(sor);
         
         // create new file
         File fi = new File("C://test.txt");
         fis = new FileInputStream(fi);
         
         int i=0;
         while((i=fis.read())!=-1)
         {
            char c=(char)i;
            System.out.print(c);
         }
      }catch(Exception ex) {
         
         ex.printStackTrace();
      }finally{
         
         if(fis!=null)
            fis.close();
      }
   }
}

The DemoSchemaOutputResolver class extends to the SchemaOutputResolver. A blank test.txt file is created and referenced to the program where the XSD content will be generated.

package com.tutorialspoint;

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

import javax.xml.bind.SchemaOutputResolver;
import javax.xml.transform.Result;
import javax.xml.transform.stream.StreamResult;

public class DemoSchemaOutputResolver extends SchemaOutputResolver {

   @Override
   public Result createOutput(String namespaceUri, String suggestedFileName)
      throws IOException {
      
      // create new file
      File file = new File("c://test.txt");
      
      // create stream result
      StreamResult result = new StreamResult(file);
      
      // set system id
      result.setSystemId(file.toURI().toURL().toString());
      
      // return result
      return result;
   }
}

Before we proceed for compilation, we need to make sure that that we download JAXB2.xxx.jar and put it in our CLASSPATH. Once setup is ready, let us compile and run the above program, this will produce the following result −

<?xml version = "1.0" encoding = "UTF-8" standalone = "yes"?>
<xs:schema version = "1.0" xmlns:xs = "http://www.w3.org/2001/XMLSchema">

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

  <xs:complexType name = "student">
    <xs:sequence>
      <xs:element name = "age" type = "xs:int"/>
      <xs:element name = "name" type="xs:string" minOccurs = "0"/>
    </xs:sequence>
    <xs:attribute name = "id" type = "xs:int" use = "required"/>
  </xs:complexType>
</xs:schema>