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Integration Project- Micro Services Migration Story with JBoss BPM Travel Agency - Part Three

Part Three - Retrieving Data with JDBC


In the post, I am going to show you how to create the fuse side travel agency demo from scratch. In the original Traveling Agency project, the hotel and flight information are all hardcoded in the application, in the Fuse version, I moved the settings to database. So in the project, you will find that there is a H2 database (File) installed. If you want to know more about the micro service architecture of the demo, please see this post for more details. We are going to concentrate on creating the promotion recommendation service of flights and hotel. Using the Camel JDBC components. I am using Hotel promotion service as example, the same applies to flight too, This service lists all the available hotels to the client with condition like the location of the hotels. After retrieving all the possible hotel data from database, it'll either randomly pick one of them, or create a default hotel.

First we need to collect the request from messaging broker, then using the input as parameters in our SQL statement, then query database using Camel-JDBC component, and process the list into Java object, then randomly choose on hotel from the list using a customize POJO bean. At last return the result back to broker.

There are two configuration you will need to predefine 2 configuration, 
1. Location and authentication of messaging broker

      
  
  

2. Datasource 

  
  
  
  
 
I love to turn data into POJO so it's easier to process in my java code, therefore I am going to create an object type "ResortInfo" to hold the data.
package org.blogdemo.travelagency.promotionhotel;

import java.io.Serializable;
import java.math.BigDecimal;

public class ResortInfo implements Serializable{

  private static final long serialVersionUID =  
   6313854994010205L;
  int hotelId;
  String hotelName;
  BigDecimal ratePerPerson;
  String hotelCity;
  String availableFrom;
  String availableTo;
  public int getHotelId() {return hotelId; }
  public void setHotelId(int hotelId) {
    this.hotelId = hotelId; 
  }
  public String getHotelName() {return hotelName;}
  public void setHotelName(String hotelName) {
    this.hotelName = hotelName;
  }
  public BigDecimal getRatePerPerson() {
    return   ratePerPerson;
  }
  public void setRatePerPerson(BigDecimal ratePerPerson){
    this.ratePerPerson = ratePerPerson;
  }
  public String getHotelCity() {return hotelCity;}
  public void setHotelCity(String hotelCity) {
    this.hotelCity = hotelCity;
  }
  public String getAvailableFrom() {return availableFrom;}
  public void setAvailableFrom(String availableFrom){
    this.availableFrom = availableFrom;
  }
  public String getAvailableTo() {return availableTo;}
  public void setAvailableTo(String availableTo){ 
    this.availableTo = availableTo;
  }
}


The current Camel version I am using does not support automatically mapping ResultSet to POJO, so I wrote a helper class to do it. (Don't worry, Camel version 2.14 will have this.) 

package org.blogdemo.travelagency.promotionhotel;

import java.math.BigDecimal;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class ResortDataConvertor {

  public List processResultSet(List> resultset){
  List avaliableResorts = new ArrayList();
  System.out.println("resultset:["+resultset.size()+"]");
    for(Map obj:resultset){
      ResortInfo resortInfo = new ResortInfo();
      resortInfo.setHotelId((Integer)obj.get("HOTELID"));
      resortInfo.setHotelName((String)obj.get("HOTELNAME"));
      resortInfo.setHotelCity((String)obj.get("HOTELCITY"));
      resortInfo.setAvailableFrom(new SimpleDateFormat("MM-dd-yyyy HH:mm:ss").format(obj.get("AVAILABLEFROM")));
      resortInfo.setAvailableTo(new SimpleDateFormat("MM-dd-yyyy HH:mm:ss").format(obj.get("AVAILABLETO")));
      resortInfo.setRatePerPerson((BigDecimal)obj.get("RATEPERPERSON"));
      avaliableResorts.add(resortInfo);
    }
   return avaliableResorts;
  } 
}


Because of the restriction in the business flow, we can only return one hotel at a time, create the java class that randomly choose one hotel, and also create a default one if no criteria is matched in database.

package org.blogdemo.travelagency.promotionhotel;

import java.math.BigDecimal;
import java.util.List;
import java.util.Random;
import org.apache.camel.Exchange;
import org.apache.camel.Processor;

public class RandomHotelBean implements Processor{
  @Override
  public void process(Exchange exchange) throws Exception {
    List resorts = (List)exchange.getIn().getBody();
    ResortInfo resort;    
    if(resorts == null || resorts.size() == 0){
      resort = new ResortInfo();
      resort.setHotelId(201);
      resort.setHotelName("The Grand Default Hotel");
      resort.setHotelCity((String)exchange.getIn().getHeader("requestCity"));
      resort.setAvailableFrom((String)exchange.getIn().getHeader("requestStartDate"));
      resort.setAvailableTo((String)exchange.getIn().getHeader("requestEndDate"));
      resort.setRatePerPerson(new BigDecimal("109.99"));
    }else{
      Random rand = new Random();
      int  n = rand.nextInt(resorts.size());
      resort = resorts.get(n);
    }
    exchange.getOut().setBody(resort);
  }
  
}

Don't forget to register the beans too. 



And this is the route. 



If you would like to add test, here is how you do,
package org.blogdemo.travelagency.promtionhotel;

import javax.jms.ConnectionFactory;
import static org.apache.camel.component.jms.JmsComponent.jmsComponentAutoAcknowledge;


import org.apache.camel.CamelContext;
import org.apache.camel.test.blueprint.CamelBlueprintTestSupport;
import org.junit.Test;

public class RouteTest extends CamelBlueprintTestSupport {
 
  protected String componentName = "activemq";
 
    @Override
    protected String getBlueprintDescriptor() {
        return "/OSGI-INF/blueprint/blueprint.xml";
    }
    
    protected CamelContext createCamelContext() throws Exception {
        CamelContext camelContext = super.createCamelContext();

        ConnectionFactory connectionFactory = CamelJmsTestHelper.createConnectionFactory();
        camelContext.addComponent(componentName, jmsComponentAutoAcknowledge(connectionFactory));

        return camelContext;
    }

    @Test
    public void testRoute() throws Exception {
     String out = template.requestBody("activemq:queue:requestHotel", "{\"startCity\":\"London\",\"startDate\":\"2015-01-01\",\"endDate\":\"2015-03-01\"}", String.class);
     
     assertEquals("{\"hotelId\":201,\"hotelName\":\"The Grand Default Hotel\",\"ratePerPerson\":109.99,\"hotelCity\":null,\"availableFrom\":\"2015-01-01\",\"availableTo\":\"2015-03-01\"}", out);
     
    }

}

For more details steps, such as setting up dependencies, see here.


Next time we will take a look persistence with JPA.

For more detail side in BPM Suite, please click here to Eric Schabell's post.

Micro Services Migration Story with JBoss BPM Travel Agency
Part One: Introduction and Installation
Part Two: Moving towards Microservices
Part Three: Retrieving Data with JDBC 

Comments

Hi Christi I was able to implement your code in camel:run, But I am unable to deploy the project in fuse 6.1 OSGI container.

I am getting following exception

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'camel-12': Invocat
ion of init method failed; nested exception is org.springframework.beans.factory.CannotLoadBeanClassExcept
ion: Cannot find class [org.apache.camel.component.jpa.JpaComponent] for bean with name 'jpa' defined in
RL [bundle://491.0:0/META-INF/spring/camel-context.xml];

Thanks for help in advance.

Lk

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