bookbuyerservlet.java

java web services how to program

// Fig. 11.19: BookBuyerServlet.java
// BookBuyerServlet uses a message provider (BuyerProvider)
// to send messages to SellerProvider.
package com.deitel.jws1.jaxm.bookbuyer.sender;

// Java core packages
import java.io.*;
import java.util.*;

// Java extension packages
import javax.servlet.http.*;
import javax.servlet.*;
import javax.xml.messaging.*;
import javax.xml.soap.*;

// ebXML packages
import com.sun.xml.messaging.jaxm.ebxml.*;

public class BookBuyerServlet extends HttpServlet {

   private ProviderConnection buyerProvider;
   private MessageFactory messageFactory;

   // source and destination endpoints for messages
   private String from, to;
   private Properties endPointProperties;

   // setup connection to message provider
   public void init( ServletConfig servletConfig ) 
      throws ServletException 
   {
      super.init( servletConfig );

      // establish connection to provider
      try {
         ProviderConnectionFactory providerFactory = 
            ProviderConnectionFactory.newInstance();
         buyerProvider = providerFactory.createConnection();

         // obtain URL of properties file
         java.net.URL endPointURL = getClass().getResource( 
            "endpoint.properties" );

         // load properties file
         endPointProperties = new Properties();
         endPointProperties.load( new FileInputStream( 
            endPointURL.getPath() ) );

         // obtain source and destination endpoints
         from = endPointProperties.getProperty( "from" );
         to = endPointProperties.getProperty( "to" );

         // obtain supported profiles for provider
         ProviderMetaData metaData = buyerProvider.getMetaData();
         String[] profiles = metaData.getSupportedProfiles();

         // determine whether ebXML profile is supported
         boolean isProfileSupported = false;
         for ( int i = 0; i < profiles.length; i++ )
            if ( profiles[ i ].equals( "ebxml" ) )
               isProfileSupported = true;

         // use ebXML profile, if supported
         if ( isProfileSupported )
            messageFactory = 
               buyerProvider.createMessageFactory( "ebxml" );
         else
            throw new ServletException( "Profile ebxml is " +
               "not supported." );
      } 

      // handle exception in connecting to provider
      catch ( JAXMException jaxmException ) {
         throw new ServletException( jaxmException.getMessage() +
            "\nUnable to connect to message provider." );
      }

      // handle exception if unable to locate Endpoint.properties
      catch ( FileNotFoundException fileNotFoundException ) {
         throw new ServletException( 
            fileNotFoundException.getMessage() +
            "\nUnable to locate endpoint.properties." );
      }

      // handle exception in loading properties file
      catch ( IOException ioException ) {
         throw new ServletException( ioException.getMessage() +
            "\nUnable to load endpoint.properties." );
      }

   } // end method init

   // invoked when client makes get request
   public void doGet( HttpServletRequest request, 
      HttpServletResponse response ) throws ServletException
   {
      // create ebXML message for BuyerProvider
      try {

         // create ebXML message
         EbXMLMessageImpl message = 
            ( EbXMLMessageImpl ) messageFactory.createMessage();

         // set send and receive provider
         message.setSender( new Party( from ) );
         message.setReceiver( new Party( to ) );

         // store ISBN in message attachment
         AttachmentPart isbnAttachment = 
            message.createAttachmentPart();
         isbnAttachment.setContent( request.getParameter( 
            "ISBN" ), "text/plain" );

         // store quantity in message attachment
         AttachmentPart quantityAttachment = 
            message.createAttachmentPart();
         quantityAttachment.setContent( request.getParameter( 
            "Quantity" ), "text/plain" );

         // add ISBN and Quantity attachments to message
         message.addAttachmentPart( isbnAttachment );
         message.addAttachmentPart( quantityAttachment );

         // send message from BuyerProvider to Web service
         buyerProvider.send( message );

         // display HTML confirmation message to client
         response.setContentType( "text/html" );
         PrintWriter out = response.getWriter();
         String viewOrderURL = 
            endPointProperties.getProperty( "viewOrderURL" );
         out.println( "<html>" );
         out.println( "<body>Order placed." );
         out.println( "Visit <a href=" + viewOrderURL + ">" );
         out.println( viewOrderURL + "</a>" );
         out.println( "to view order status.</body>" );
         out.println( "</html>" );
      }

      // handle exception in using message provider
      catch ( JAXMException jaxmException ) {
         throw new ServletException( jaxmException.getMessage() +
            "\nError in using message provider." );
      }

      // handle exception in creating SOAP messages
      catch ( SOAPException soapException ) {
         throw new ServletException( soapException.getMessage() +
            "\nUnable to create SOAP message." );
      }

      // handle exception if servlet not initialized
      catch ( NullPointerException nullException ) {
         throw new ServletException( nullException.getMessage() +
            "\nServlet not initialized properly." );
      }

      // handle exception in writing HTML to client
      catch ( IOException ioException ) {
         throw new ServletException( ioException.getMessage() +
            "\nServlet not initialized properly." );
      }

   } // end method doGet

} // end class BookBuyerServlet