Castor Unmarshalling Error

[Sree Potluri]

When I am unmarshalling the xml, I get Null pointer Exception, can any one help me please.

org.exolab.castor.mapping.Mapping setBaseURL
INFO: C:\Users\NetBeansProjects\TestWebApplication\src\java\testing is not a URL, trying to convert it to a file URL
Oct 10, 2010 1:54:56 AM org.exolab.castor.mapping.Mapping loadMapping
INFO: Loading mapping descriptors from book-mapping.xml
Subject null
First Name null
java.lang.NullPointerException
Last Name null
at testing.BookUnmarshall.main(BookUnmarshall.java:39)
BUILD SUCCESSFUL (total time: 2 seconds)

sample.xml

 <?xml version="1.0" ?>
<Books>
  <BookType>
    <Book_Info>
      <subject>Science</subject>
    </Book_Info>
    <Authors>
      <Author_Info>
        <LastName>jim</LastName>
        <FirstName>Brad</FirstName>
      </Author_Info>
      <Book_Title>
        <Name>Science Fiction</Name>
        <Other_Authors>
          <Last>criag</Last>
          <First>Lee</First>
        </Other_Authors> 
    <Info> 
      <isbn>12345</isbn>
        </Info>
      </Book_Title> 
    <Book_Title>
        <Name>Science Fiction</Name>
        <Other_Authors>
          <Last>Max</Last>
          <First>light</First>
        </Other_Authors> 
    <Info> 
      <isbn>12345</isbn>
        </Info>
      </Book_Title> 
    <Book_Title>
        <Name>Science Fiction</Name>
        <Other_Authors>
          <Last>tim</Last>
          <First>jack</First>
        </Other_Authors> 
    <Info> 
      <isbn>12345</isbn>
        </Info>
      </Book_Title> 
    </Authors>
  </BookType>
</Books>
     

BookUnmarshal.java

   package testing;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.exolab.castor.mapping.Mapping;
import org.exolab.castor.mapping.MappingException;
import org.exolab.castor.xml.MarshalException;
import org.exolab.castor.xml.Unmarshaller;
import org.exolab.castor.xml.ValidationException;

public class BookUnmarshall{

    public static void main(String[] args) {
        Mapping mapping = new Mapping();
        try{
             mapping.loadMapping("C:\\Users\\NetBeansProjects\\TestWebApplication\\src\\java\\testing\\book-mapping.xml");
             FileReader reader = new FileReader("C:\\Users\\sample.xml");
            Unmarshaller unmarshaller = new Unmarshaller(BookInfo.class);
            BookInfo book = (BookInfo)unmarshaller.unmarshal(reader);
            unmarshaller.setMapping(mapping);
            System.out.println("Subject "+book.getSubject());
            System.out.println("First Name "+book.getFirstName());
            System.out.println("Last Name "+book.getLastName());
            List<BookTitle> bookTitle = book.getBookTitle();
            for(Iterator i=bookTitle.iterator();i.hasNext();){
                BookTitle title = (BookTitle)i.next();
                System.out.println("Name "+title.getName());
                List<OtherAuthors> otherAuthors = title.getOtherAuthors();
                for (Iterator j=otherAuthors.iterator();j.hasNext();){
                    OtherAuthors author = (OtherAuthors)j.next();
                    System.out.println("First Name  "+author.getFirst());
                    System.out.println("Last Name "+author.getLast());
                    List<Info> infoList = author.getInfo();
                    for(Iterator k=infoList.iterator();k.hasNext();){
                        Info info = (Info)k.next();
                       System.out.println("ISBN "+info.getIsbn());
                    }
                }
            }
        } catch (MarshalException ex) {
            ex.printStackTrace();
        } catch (ValidationException ex) {
            ex.printStackTrace();
        } catch (MappingException ex) {
            ex.printStackTrace();
        } catch (FileNotFoundException ex) {
            ex.printStackTrace();
        } catch (IOException ex) {
            ex.printStackTrace();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
 } 

book-mapping.xml

 <mapping>
  <class name="testing.BookInfo">
    <map-to xml="C:\\Users\\NetBeansProjects\\TestWebApplication\\testing\\Sample" />

    <field name="subject" type="java.lang.String">
      <bind-xml name="title" node="element" location="Book-Info" />
    </field>
    <field name="lastName" type="java.lang.String">
      <bind-xml name="LastName" node="element" location="Author_Info" />
    </field>
    <field name="firstName" type="java.lang.String">
      <bind-xml name="FirstName" node="element" location="Author_Info" />
    </field>
    <field name="BookTitle" type="testing.BookTitle" collection="vector">
      <bind-xml name="Book_Title" />
    </field>
  </class>
  <class name="testing.BookTitle">
    <field name="name" type="java.lang.String">
      <bind-xml name="Name" node="attribute" location="Book_Title" />
    </field>
    <field name="OtherAuthors" type="testing.OtherAuthors" collection="vector">
      <bind-xml name="Other_Authors"/>
    </field>
  </class>
  <class name="testing.OtherAuthors">
      <field name="last" type="java.lang.String">
          <bind-xml name="Last" node="attribute" location="Other_Authors"/>
      </field>
      <field name="first" type="java.lang.String">
          <bind-xml name="First" node="attribute" location="Other_Authors"/>
      </field>
      <field name="Info" type="testing.Info" collection="vector">
          <bind-xml name="isbn" node="attribute" location="Info"/>
      </field>
  </class>
</mapping>   

BookInfo.java

   package testing;

import java.util.List;

public class BookInfo {

    private String subject;
    private String lastName;
    private String firstName;
    private List<BookTitle> bookTitle;

    public String getSubject() {
        return subject;
    }

    public void setSubject(String subject) {
        this.subject = subject;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public List<BookTitle> getBookTitle() {
        return bookTitle;
    }

    public void setBookTitle(List<BookTitle> bookTitle) {
        this.bookTitle = bookTitle;
    }
}
 

BookTitle.java

  package testing;

import java.util.List;

public class BookTitle {

    private String name;
    private List<OtherAuthors> otherAuthors;

    public String getName() {
        return name;
    }

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

    public List<OtherAuthors> getOtherAuthors() {
        return otherAuthors;
    }

    public void setOtherAuthors(List<OtherAuthors> otherAuthors) {
        this.otherAuthors = otherAuthors;
    }
}  

OtherAuthors.java

package testing;

import java.util.List;

public class OtherAuthors {

    private String last;
    private String first;
    private List<Info> info;

    public String getLast() {
        return last;
    }

    public void setLast(String last) {
        this.last = last;
    }

    public String getFirst() {
        return first;
    }

    public void setFirst(String first) {
        this.first = first;
    }

    public List<Info> getInfo() {
        return info;
    }

    public void setInfo(List<Info> info) {
        this.info = info;
    }
}

Info.java

package testing;

public class Info {

    private int isbn;

    /**
     * @return the isbn
     */
    public int getIsbn() {
        return isbn;
    }

    /**
     * @param isbn the isbn to set
     */
    public void setIsbn(int isbn) {
        this.isbn = isbn;
    }
}