Spring Integration provides Channel Adapters for receiving and sending messages via database queries. Through those adapters Spring Integration supports not only plain JDBC SQL Queries, but also Stored Procedure and Stored Function calls. The following JDBC components are available by default: Inbound Channel Adapter Outbound Channel Adapter Outbound Gateway Stored Procedure Inbound Channel Adapter Stored Procedure Outbound Channel Adapter Stored Procedure Outbound Gateway Furthermore, the Spring Integration JDBC Module also provides a JDBC Message Store

The main function of an inbound Channel Adapter is to execute a SQL SELECT query and turn the result set as a message. The message payload is the whole result set, expressed as a List, and the types of the items in the list depend on the row-mapping strategy that is used. The default strategy is a generic mapper that just returns a Map for each row in the query result. Optionally, this can be changed by adding a reference to a RowMapper instance (see the Spring JDBC documentation for more detailed information about row mapping). If you want to convert rows in the SELECT query result to individual messages you can use a downstream splitter. The inbound adapter also requires a reference to either a JdbcTemplate instance or a DataSource. As well as the SELECT statement to generate the messages, the adapter above also has an UPDATE statement that is being used to mark the records as processed so that they don't show up in the next poll. The update can be parameterized by the list of ids from the original select. This is done through a naming convention by default (a column in the input result set called "id" is translated into a list in the parameter map for the update called "id"). The following example defines an inbound Channel Adapter with an update query and a DataSource reference. ]]> The parameters in the update query are specified with a colon (:) prefix to the name of a parameter (which in this case is an expression to be applied to each of the rows in the polled result set). This is a standard feature of the named parameter JDBC support in Spring JDBC combined with a convention (projection onto the polled result list) adopted in Spring Integration. The underlying Spring JDBC features limit the available expressions (e.g. most special characters other than period are disallowed), but since the target is usually a list of or an individual object addressable by simple bean paths this isn't unduly restrictive. To change the parameter generation strategy you can inject a SqlParameterSourceFactory into the adapter to override the default behavior (the adapter has a sql-parameter-source-factory attribute).

The inbound adapter accepts a regular Spring Integration poller as a sub element, so for instance the frequency of the polling can be controlled. A very important feature of the poller for JDBC usage is the option to wrap the poll operation in a transaction, for example: ]]> If a poller is not explicitly specified, a default value will be used (and as per normal with Spring Integration can be defined as a top level bean). In this example the database is polled every 1000 milliseconds, and the update and select queries are both executed in the same transaction. The transaction manager configuration is not shown, but as long as it is aware of the data source then the poll is transactional. A common use case is for the downstream channels to be direct channels (the default), so that the endpoints are invoked in the same thread, and hence the same transaction. Then if any of them fail, the transaction rolls back and the input data is reverted to its original state.

The outbound Channel Adapter is the inverse of the inbound: its role is to handle a message and use it to execute a SQL query. The message payload and headers are available by default as input parameters to the query, for instance: ]]> In the example above, messages arriving on the channel labelled input have a payload of a map with key foo, so the [] operator dereferences that value from the map. The headers are also accessed as a map. The parameters in the query above are bean property expressions on the incoming message (not Spring EL expressions). This behavior is part of the SqlParameterSource which is the default source created by the outbound adapter. Other behavior is possible in the adapter, and requires the user to inject a different SqlParameterSourceFactory. The outbound adapter requires a reference to either a DataSource or a JdbcTemplate. It can also have a SqlParameterSourceFactory injected to control the binding of each incoming message to a query. If the input channel is a direct channel, then the outbound adapter runs its query in the same thread, and therefore the same transaction (if there is one) as the sender of the message. Passing Parameters using SpEL Expressions A common requirement for most JDBC Channel Adapters is to pass parameters as part of Sql queries or Stored Procedures/Functions. As mentioned above, these parameters are by default bean property expressions, not SpEL expressions. However, if you need to pass SpEL expression as parameters, you must inject a SqlParameterSourceFactory explicitly. The following example uses a ExpressionEvaluatingSqlParameterSourceFactory to achieve that requirement. ]]> For further information, please also see

The outbound Gateway is like a combination of the outbound and inbound adapters: its role is to handle a message and use it to execute a SQL query and then respond with the result sending it to a reply channel. The message payload and headers are available by default as input parameters to the query, for instance: ]]> The result of the above would be to insert a record into the "foos" table and return a message to the output channel indicating the number of rows affected (the payload is a map: {UPDATED=1}). If the update query is an insert with auto-generated keys, the reply message can be populated with the generated keys by adding keys-generated="true" to the above example (this is not the default because it is not supported by some database platforms). For example: ]]> Instead of the update count or the generated keys, you can also provide a select query to execute and generate a reply message from the result (like the inbound adapter), e.g: ]]> As with the channel adapters, there is also the option to provide SqlParameterSourceFactory instances for request and reply. The default is the same as for the outbound adapter, so the request message is available as the root of an expression. If keys-generated="true" then the root of the expression is the generated keys (a map if there is only one or a list of maps if multi-valued). The outbound gateway requires a reference to either a DataSource or a JdbcTemplate. It can also have a SqlParameterSourceFactory injected to control the binding of the incoming message to the query.

The JDBC module provides an implementation of the Spring Integration MessageStore (important in the Claim Check pattern) and MessageGroupStore (important in stateful patterns like Aggregator) backed by a database. Both interfaces are implemented by the JdbcMessageStore, and there is also support for configuring store instances in XML. For example: ]]> A JdbcTemplate can be specified instead of a DataSource. Other optional attributes are show in the next example: ]]> Here we have specified a LobHandler for dealing with messages as large objects (e.g. often necessary if using Oracle) and a prefix for the table names in the queries generated by the store. The table name prefix defaults to "INT_".

Spring Integration ships with some sample scripts that can be used to initialize a database. In the spring-integration-jdbc JAR file you will find scripts in the org.springframework.integration.jdbc package: there is a create and a drop script example for a range of common database platforms. A common way to use these scripts is to reference them in a Spring JDBC data source initializer. Note that the scripts are provided as samples or specifications of the the required table and column names. You may find that you need to enhance them for production use (e.g. with index declarations).

It is common to use a JdbcMessageStore as a global store for a group of applications, or nodes in the same application. To provide some protection against name clashes, and to give control over the database meta-data configuration, the message store allows the tables to be partitioned in two ways. One is to use separate table names, by changing the prefix as described above, and the other is to specify a "region" name for partitioning data within a single table. An important use case for this is when the MessageStore is managing persistent queues backing a Spring Integration Message Channel. The message data for a persistent channel is keyed in the store on the channel name, so if the channel names are not globally unique then there is the danger of channels picking up data that was not intended for them. To avoid this, the message store region can be used to keep data separate for different physical channels that happen to have the same logical name.

In certain situations plain JDBC support is not sufficient. Maybe you deal with legacy relational database schemas or you have complex data processing needs, but ultimately you have to use Stored Procedures or Stored Functions. Since Spring Integration 2.1, we provide three components in order to execute Stored Procedures or Stored Functions: Stored Procedures Inbound Channel Adapter Stored Procedures Outbound Channel Adapter Stored Procedures Outbound Gateway

In order to enable calls to Stored Procedures and Stored Functions, the Stored Procedure components use the org.springframework.jdbc.core.simple.SimpleJdbcCall class. Consequently, the following databases are fully supported for executing Stored Procedures: Apache Derby DB2 MySQL Microsoft SQL Server Oracle PostgreSQL Sybase If you want to exute Stored Functions instead, the following databases are fully supported: MySQL Microsoft SQL Server Oracle PostgreSQL

Even though your particular database may not be fully supported, chances are, that you can use the Stored Procedure Spring Integration components quite successfully anyway, provided your RDBMS supports Stored Procedures or Functions. As a matter of fact, some of the provided integration tests use the H2 database. Nevertheless, it is very important to thoroughly test those usage scenarios.

The Stored Procedure components provide full XML Namespace support and configuring the components is similar as for the general purpose JDBC components discussed earlier.

Certain configuration parameters are shared among all Stored Procedure components and are described below: auto-startup Lifecycle attribute signaling if this component should be started during Application Context startup. Defaults to true. Optional. data-source Reference to a javax.sql.DataSource, which is used to access the database. Required. id Identifies the underlying Spring bean definition, which is an instance of either EventDrivenConsumer or PollingConsumer, depending on whether the Outbound Channel Adapter's channel attribute references a SubscribableChannel or a PollableChannel. Optional. ignore-column-meta-data For fully supported databases, the underlying SimpleJdbcCall class can automatically retrieve the parameter information for the to be invoked Stored Procedure or Function from the JDBC Meta-data. However, if the used database does not support meta data lookups or if you like to provide customized parameter definitions, this flag can be set to true. It defaults to false. Optional. is-function If true, a SQL Function is called. In that case the stored-procedure-name attribute defines the name of the called function. Defaults to false. Optional. stored-procedure-name The attribute specifies the name of the stored procedure. If the is-function attribute is set to true, this attribute specifies the function name. Required. sql-parameter-source-factory (Not available for the Stored Procedure Inbound Channel Adapter.) Reference to a SqlParameterSourceFactory. By default bean properties of the passed in Message payload will be used as a source for the Stored Procedure's input parameters using a BeanPropertySqlParameterSourceFactory. This may be sufficient for basic use cases. For more sophisticated options, consider passing in one or more ProcedureParameter. Please also refer to . Optional. use-payload-as-parameter-source (Not available for the Stored Procedure Inbound Channel Adapter.) If set to true, the payload of the Message will be used as a source for providing parameters. If false, however, the entire Message will be available as a source for parameters. If no Procedure Parameters are passed in, this property will default to true. This means that using a default BeanPropertySqlParameterSourceFactory the bean properties of the payload will be used as a source for parameter values for the to-be-executed Stored Procedure or Stored Function. However, if Procedure Parameters are passed in, then this property will by default evaluate to false. ProcedureParameter allow for SpEL Expressions to be provided and therefore it is highly beneficial to have access to the entire Message. The property is set on the underlying StoredProcExecutor. Optional.

The Stored Procedure components share a common set of sub-elements to define and pass parameters to Stored Procedures or Functions. The following elements are available: parameter returning-resultset sql-parameter-definition poller parameter Provides a mechanism to provide Stored Procedure parameters. Parameters can be either static or provided using a SpEL Expressions. Optional. ]]>]]> The name of the parameter to be passed into the Stored Procedure or Stored Function. Required. This attribute specifies the type of the value. If nothing is provided this attribute will default to java.lang.String. This attribute is only used when the value attribute is used. Optional. The value of the parameter. You have to provider either this attribute or the expression attribute must be provided instead. Optional. Instead of the value attribute, you can also specify a SpEL expression for passing the value of the parameter. If you specify the expression the value attribute is not allowed. Optional. returning-resultset Stored Procedures may return multiple resultsets. By setting one or more returning-resultset elements, you can specify RowMappers in order to convert each returned ResultSet to meaningful objects. Optional. ]]> sql-parameter-definition If you are using a database that is fully supported, you typically don't have to specify the Stored Procedure parameter definitions. Instead, those parameters can be automatically derived from the JDBC Meta-data. However, if you are using databases that are not fully supported, you must set those parameters explicitly using the sql-parameter-definition sub-element. You can also choose to turn off any processing of parameter meta data information obtained via JDBC using the ignore-column-meta-data attribute. ]]> Specifies the name of the SQL parameter. Required. Specifies the direction of the SQL parameter definition. Defaults to IN. Valid values are: IN, OUT and INOUT. If your procedure is returning ResultSets, please use the returning-resultset element. Optional. The SQL type used for this SQL parameter definition. Will translate into the integer value as defined by java.sql.Types. Alternatively you can provide the integer value as well. If this attribute is not explicitly set, then it will default to 'VARCHAR'. Optional. The scale of the SQL parameter. Only used for numeric and decimal parameters. Optional. poller Allows you to configure a Message Poller if this endpoint is a PollingConsumer. Optional.

Parameter Sources govern the techniques of retrieving and mapping the Spring Integration Message properties to the relevant Stored Procedure input parameters. The Stored Procedure components follow certain rules. By default bean properties of the passed in Message payload will be used as a source for the Stored Procedure's input parameters. In that case a BeanPropertySqlParameterSourceFactory will be used. This may be sufficient for basic use cases. The following example illustrates that default behavior. Please be aware that for the "automatic" lookup of bean properties using the BeanPropertySqlParameterSourceFactory to work, your bean properties must be defined in lower case. This is due to the fact that in org.springframework.jdbc.core.metadata.CallMetaDataContext (method matchInParameterValuesWithCallParameters()), the retrieved Stored Procedure parameter declarations are converted to lower case. As a result, if you have camel-case bean properties such as "lastName", the lookup will fail. In that case, please provide an explicit ProcedureParameter. Let's assume we have a payload that consists of a simple bean with the following three properties: id, name and description. Furthermore, we have a simplistic Stored Procedure called INSERT_COFFEE that accepts three input parameters: id, name and description. We also use a fully supported database. In that case the following configuration for a Stored Procedure Oubound Adapter will be sufficient: ]]> For more sophisticated options consider passing in one or more ProcedureParameter. If you do provide ProcedureParameter explicitly, then as default an ExpressionEvaluatingSqlParameterSourceFactory will be used for parameter processing in order to enable the full power of SpEL expressions. Furthermore, if you need even more control over how parameters are retrieved, consider passing in a custom implementation of a SqlParameterSourceFactory using the sql-parameter-source-factory attribute.

]]> Channel to which polled messages will be sent. If the stored procedure or function does not return any data, the payload of the Message will be Null. Required. Limits the number of rows extracted per query. Otherwise all rows are extracted into the outgoing message. Optional. If this attribute is set to true, then all results from a stored procedure call that don't have a corresponding SqlOutParameter declaration will be bypassed. E.g. Stored Procedures may return an update count value, even though your Stored Procedure only declared a single result parameter. The exact behavior depends on the used database. The value is set on the underlying JdbcTemplate. Few developers will probably ever want to process update counts, thus the value defaults to true. Optional.

]]> The receiving Message Channel of this endpoint. Required. Specifies the order for invocation when this endpoint is connected as a subscriber to a channel. This is particularly relevant when that channel is using a failover dispatching strategy. It has no effect when this endpoint itself is a Polling Consumer for a channel with a queue. Optional. Indicates whether this procedure's return value should be included. Optional.

]]> The receiving Message Channel of this endpoint. Required. Message Channel to which replies should be sent, after receiving the database response. Optional. Allows you to specify how long this gateway will wait for the reply message to be sent successfully before throwing an exception. Keep in mind that when sending to a DirectChannel, the invocation will occur in the sender's thread so the failing of the send operation may be caused by other components further downstream. By default the Gateway will wait indefinitely. The value is specified in milliseconds. Optional. Indicates whether this procedure's return value should be included. Optional. If the skip-undeclared-results attribute is set to true, then all results from a stored procedure call that don't have a corresponding SqlOutParameter declaration will be bypassed. E.g. Stored Procedures may return an update count value, even though your Stored Procedure only declared a single result parameter. The exact behavior depends on the used database. The value is set on the underlying JdbcTemplate. Few developers will probably ever want to process update counts, thus the value defaults to true. Optional.

In the following two examples we call Apache Derby Stored Procedures. The first procedure will call a Stored Procedure that returns a ResultSet, and using a RowMapper the data is converted into a domain object, which then becomes the Spring Integration message payload. In the second sample we call a Stored Procedure that uses Output Parameters instead, in order to return data. Please have a look at the Spring Integration Samples project, located at The project contains the Apache Derby example referenced here, as well as instruction on how to run it. The Spring Integration Samples project also provides an example using Oracle Stored Procedures. In the first example, we call a Stored Procedure named FIND_ALL_COFFEE_BEVERAGES that does not define any input parameters but which returns a ResultSet. In Apache Derby, Stored Procedures are implemented using Java. Here is the method signature followed by the corresponding Sql: In Spring Integration, you can now call this Stored Procedure using e.g. a stored-proc-outbound-gateway ]]> In the second example, we call a Stored Procedure named FIND_COFFEE that has one input parameter. Instead of returning a ResultSet, an output parameter is used: In Spring Integration, you can now call this Stored Procedure using e.g. a stored-proc-outbound-gateway ]]>