spring-integration-samples/basic/jdbc/README.md

Spring Integration - JDBC Sample
================================

## Overview

This sample provides example of how the JDBC Adapters can be used.
The example presented covers the following use cases

* Find a Person detail from the database based on the name provided
* Create a new Person record in the table

The first example demonstrates the use of *Outbound Gateway* to search for a person record using *Spring Integration*'s *JDBC Outbound Gateway*.

The second example on other hand demonstrates how the *JDBC Outbound Gateway* can be used to create a new *Person* record and then return the newly created *Person* record. This example  demonstrates how to make use of the sql parameter source factory to extract the required values to be inserted/updated/selected in the query provided.

## Getting Started

You can run the application by either

* running the "Main" class from within STS (Right-click on Main class --> Run As --> Java Application)
* or from the command line:
    
    $ gradlew :jdbc:run
    
Make an appropriate choice for searching a Person or creating a Person.

For creating the person record, select the appropriate steps as prompted by the application.

On creation of *Person* records, you may choose the option of selecting the created person records and view their details.

## Details

We use the outbound gateway to insert records in a Person table based on the values contained
in the message payload that is received over the channel to the adapter.

The following are used to configure the *Gateway*:

* The request and reply channels
* The data source for the database
* The the update/insert statement to be executed.
* Optional request SQL Parameter source factory
* The select query to be executed after the insert is done
* Optional reply SQL Parameter source factory
* RowMapper if you intend to map the ResultSet to your custom object

The following sequence of events happen when we invoke the *createPerson* method on the *Gateway*:

* The parameter of type Person is sent as a payload of a message over the reply-channel
* The outbound gateway reads this message and extracts the payload
* It then executes the given insert statement, the values to be inserted are derived from the payload 
	request-sql-parameter-source-factory provided is used to generate a parameter source.
* Since we expect an identity column to be generated, keys-generated is set to true
* The result of the insert is then use to create a reply sql parameter source, 
	the factory reply-sql-parameter-source-factory generates the required parameter source
* The select query provided is executed
* The ResultMapper is used to convert this ResultSet to a Person object
* The Person object is then sent as a payload of the Message over the reply channel.
* The Person payload is extracted from the Message and returned to the calling application.

## Running the Sample

For executing the program and see the results, execute the junit test case
**org.springframework.integration.samples.jdbc.OutboundGatewayTest**

## Resources

For help please take a look at the Spring Integration documentation:

https://www.springsource.org/spring-integration