SQL Stored Procedure

Since Camel 2.17

Only producer is supported

The SQL Stored component allows you to work with databases using JDBC Stored Procedure queries. This component is an extension to the SQL Component but specialized for calling stored procedures.

This component uses spring-jdbc behind the scenes for the actual SQL handling.

Maven users will need to add the following dependency to their pom.xml for this component:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-sql</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>

URI format

The SQL component uses the following endpoint URI notation:

sql-stored:template[?options]

Where template is the stored procedure template, where you declare the name of the stored procedure and the IN, INOUT, and OUT arguments.

You can also refer to the template in an external file on the file system or classpath such as:

sql-stored:classpath:sql/myprocedure.sql[?options]

Where sql/myprocedure.sql is a plain text file in the classpath with the template, as show:

SUBNUMBERS(
  INTEGER ${headers.num1},
  INTEGER ${headers.num2},
  INOUT INTEGER ${headers.num3} out1,
  OUT INTEGER out2
)

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

At the component level, you set general and shared configurations that are, then, inherited by the endpoints. It is the highest configuration level.

For example, a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre-configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

You can configure components using:

  • the Component DSL.

  • in a configuration file (application.properties, *.yaml files, etc).

  • directly in the Java code.

Configuring Endpoint Options

You usually spend more time setting up endpoints because they have many options. These options help you customize what you want the endpoint to do. The options are also categorized into whether the endpoint is used as a consumer (from), as a producer (to), or both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java.

A good practice when configuring options is to use Property Placeholders.

Property placeholders provide a few benefits:

  • They help prevent using hardcoded urls, port numbers, sensitive information, and other settings.

  • They allow externalizing the configuration from the code.

  • They help the code to become more flexible and reusable.

The following two sections list all the options, firstly for the component followed by the endpoint.

Component Options

The SQL Stored Procedure component supports 4 options, which are listed below.

Name Description Default Type

dataSource (producer)

Autowired Sets the DataSource to use to communicate with the database.

DataSource

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

boolean

serviceLocationEnabled (advanced)

Whether to detect the network address location of the JMS broker on startup. This information is gathered via reflection on the ConnectionFactory, and is vendor specific. This option can be used to turn this off.

true

boolean

Endpoint Options

The SQL Stored Procedure endpoint is configured using URI syntax:

sql-stored:template

With the following path and query parameters:

Path Parameters (1 parameters)

Name Description Default Type

template (producer)

Required Sets the stored procedure template to perform. You can externalize the template by using file: or classpath: as prefix and specify the location of the file.

String

Query Parameters (8 parameters)

Name Description Default Type

batch (producer)

Enables or disables batch mode.

false

boolean

dataSource (producer)

Sets the DataSource to use to communicate with the database.

DataSource

function (producer)

Whether this call is for a function.

false

boolean

noop (producer)

If set, will ignore the results of the stored procedure template and use the existing IN message as the OUT message for the continuation of processing.

false

boolean

outputHeader (producer)

Store the template result in a header instead of the message body. By default, outputHeader == null and the template result is stored in the message body, any existing content in the message body is discarded. If outputHeader is set, the value is used as the name of the header to store the template result and the original message body is preserved.

String

useMessageBodyForTemplate (producer)

Whether to use the message body as the stored procedure template and then headers for parameters. If this option is enabled then the template in the uri is not used.

false

boolean

lazyStartProducer (producer (advanced))

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

templateOptions (advanced)

Configures the Spring JdbcTemplate with the key/values from the Map.

Map

Message Headers

The SQL Stored Procedure component supports 3 message header(s), which is/are listed below:

Name Description Default Type

CamelSqlStoredTemplate (producer)

Constant: SQL_STORED_TEMPLATE

The template.

String

CamelSqlStoredParameters (producer)

Constant: SQL_STORED_PARAMETERS

The parameters.

Iterator

CamelSqlStoredUpdateCount (producer)

Constant: SQL_STORED_UPDATE_COUNT

The update count.

Integer

Usage

Declaring the stored procedure template

The template is declared using a syntax that would be similar to a Java method signature. The name of the stored procedure, and then the arguments enclosed in parentheses. An example explains this well:

<to uri="sql-stored:STOREDSAMPLE(INTEGER ${headers.num1},INTEGER ${headers.num2},INOUT INTEGER ${headers.num3} result1,OUT INTEGER result2)"/>

The arguments are declared by a type and then a mapping to the Camel message using simple expression. So, in this example, the first two parameters are IN values of INTEGER type, mapped to the message headers. The third parameter is INOUT, meaning it accepts an INTEGER and then returns a different INTEGER result. The last parameter is the OUT value, also an INTEGER type.

In SQL terms, the stored procedure could be declared as:

CREATE PROCEDURE STOREDSAMPLE(VALUE1 INTEGER, VALUE2 INTEGER, INOUT RESULT1 INTEGER, OUT RESULT2 INTEGER)

IN Parameters

IN parameters take four parts separated by a space: parameter name, SQL type (with scale), type name, and value source.

Parameter name is optional and will be auto generated if not provided. It must be given between quotes(').

SQL type is required and can be an integer (positive or negative) or reference to integer field in some class. If SQL type contains a dot, then the component tries to resolve that class and read the given field. For example, SQL type com.Foo.INTEGER is read from the field INTEGER of class com.Foo. If the type doesn’t contain comma then class to resolve the integer value will be java.sql.Types. Type can be postfixed by scale for example DECIMAL(10) would mean java.sql.Types.DECIMAL with scale 10.

Type name is optional and must be given between quotes(').

Value source is required. Value source populates the parameter value from the Exchange. It can be either a Simple expression or header location i.e. :#<header name>. For example, the Simple expression ${header.val} would mean that parameter value will be read from the header val. Header location expression :#val would have identical effect.

<to uri="sql-stored:MYFUNC('param1' org.example.Types.INTEGER(10) ${header.srcValue})"/>

URI means that the stored procedure will be called with parameter name param1, it’s SQL type is read from field INTEGER of class org.example.Types and scale will be set to 10. The input value for the parameter is passed from the header srcValue.

<to uri="sql-stored:MYFUNC('param1' 100 'mytypename' ${header.srcValue})"/>

URI is identical to previous on except SQL-type is 100 and type name is mytypename.

Actual call will be done using org.springframework.jdbc.core.SqlParameter.

OUT Parameters

OUT parameters work similarly IN parameters and contain three parts: SQL type(with scale), type name, and output parameter name.

SQL type works the same as IN parameters.

Type name is optional and also works the same as IN parameters.

Output parameter name is used for the OUT parameter name, as well as the header name where the result will be stored.

<to uri="sql-stored:MYFUNC(OUT org.example.Types.DECIMAL(10) outheader1)"/>

URI means that the OUT parameter’s name is outheader1 and result will be but into header outheader1. 

<to uri="sql-stored:MYFUNC(OUT org.example.Types.NUMERIC(10) 'mytype' outheader1)"/>

This is identical to previous one but type name will be mytype.

Actual call will be done using org.springframework.jdbc.core.SqlOutParameter.

INOUT Parameters

INOUT parameters are a combination of all of the above. They receive a value from the exchange, as well as store a result as a message header. The only caveat is that the IN parameter’s "name" is skipped. Instead, the OUT parameter’s name defines both the SQL parameter name, and the result header name.

<to uri="sql-stored:MYFUNC(INOUT DECIMAL(10) ${headers.inheader} outheader)"/>

Actual call will be done using org.springframework.jdbc.core.SqlInOutParameter.

Query Timeout

You can configure query timeout (via template.queryTimeout) on statements used for query processing as shown:

<to uri="sql-stored:MYFUNC(INOUT DECIMAL(10) ${headers.inheader} outheader)?template.queryTimeout=5000"/>

This will be overridden by the remaining transaction timeout when executing within a transaction that has a timeout specified at the transaction level.

Camel SQL Starter

A starter module is available to spring-boot users. When using the starter, the DataSource can be directly configured using spring-boot properties.

# Example for a mysql datasource
spring.datasource.url=jdbc:mysql://localhost/test
spring.datasource.username=dbuser
spring.datasource.password=dbpass
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

To use this feature, add the following dependencies to your spring boot pom.xml file:

<dependency>
    <groupId>org.apache.camel.springboot</groupId>
    <artifactId>camel-sql-starter</artifactId>
    <version>${camel.version}</version> <!-- use the same version as your Camel core version -->
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
    <version>${spring-boot-version}</version>
</dependency>

You should also include the specific database driver, if needed.