Chapter 164. JDBC Component

Available as of Camel version 1.2

The jdbc component enables you to access databases through JDBC, where SQL queries (SELECT) and operations (INSERT, UPDATE, etc) are sent in the message body. This component uses the standard JDBC API, unlike the SQL Component component, which uses spring-jdbc.

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

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

This component can only be used to define producer endpoints, which means that you cannot use the JDBC component in a from() statement.

164.1. URI format

jdbc:dataSourceName[?options]

This component only supports producer endpoints.

You can append query options to the URI in the following format, ?option=value&option=value&…​

164.2. Options

The JDBC component supports 2 options which are listed below.

NameDescriptionDefaultType

dataSource (producer)

To use the DataSource instance instead of looking up the data source by name from the registry.

 

DataSource

resolveProperty Placeholders (advanced)

Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders.

true

boolean

The JDBC endpoint is configured using URI syntax:

jdbc:dataSourceName

with the following path and query parameters:

164.2.1. Path Parameters (1 parameters):

NameDescriptionDefaultType

dataSourceName

Required Name of DataSource to lookup in the Registry.

 

String

164.2.2. Query Parameters (13 parameters):

NameDescriptionDefaultType

allowNamedParameters (producer)

Whether to allow using named parameters in the queries.

true

boolean

outputClass (producer)

Specify the full package and class name to use as conversion when outputType=SelectOne or SelectList.

 

String

outputType (producer)

Determines the output the producer should use.

SelectList

JdbcOutputType

parameters (producer)

Optional parameters to the java.sql.Statement. For example to set maxRows, fetchSize etc.

 

Map

readSize (producer)

The default maximum number of rows that can be read by a polling query. The default value is 0.

 

int

resetAutoCommit (producer)

Camel will set the autoCommit on the JDBC connection to be false, commit the change after executed the statement and reset the autoCommit flag of the connection at the end, if the resetAutoCommit is true. If the JDBC connection doesn’t support to reset the autoCommit flag, you can set the resetAutoCommit flag to be false, and Camel will not try to reset the autoCommit flag. When used with XA transactions you most likely need to set it to false so that the transaction manager is in charge of committing this tx.

true

boolean

transacted (producer)

Whether transactions are in use.

false

boolean

useGetBytesForBlob (producer)

To read BLOB columns as bytes instead of string data. This may be needed for certain databases such as Oracle where you must read BLOB columns as bytes.

false

boolean

useHeadersAsParameters (producer)

Set this option to true to use the prepareStatementStrategy with named parameters. This allows to define queries with named placeholders, and use headers with the dynamic values for the query placeholders.

false

boolean

useJDBC4ColumnNameAnd LabelSemantics (producer)

Sets whether to use JDBC 4 or JDBC 3.0 or older semantic when retrieving column name. JDBC 4.0 uses columnLabel to get the column name where as JDBC 3.0 uses both columnName or columnLabel. Unfortunately JDBC drivers behave differently so you can use this option to work out issues around your JDBC driver if you get problem using this component This option is default true.

true

boolean

beanRowMapper (advanced)

To use a custom org.apache.camel.component.jdbc.BeanRowMapper when using outputClass. The default implementation will lower case the row names and skip underscores, and dashes. For example CUST_ID is mapped as custId.

 

BeanRowMapper

prepareStatementStrategy (advanced)

Allows to plugin to use a custom org.apache.camel.component.jdbc.JdbcPrepareStatementStrategy to control preparation of the query and prepared statement.

 

JdbcPrepareStatement Strategy

synchronous (advanced)

Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported).

false

boolean

164.3. Result

By default the result is returned in the OUT body as an ArrayList<HashMap<String, Object>>. The List object contains the list of rows and the Map objects contain each row with the String key as the column name. You can use the option outputType to control the result.

Note: This component fetches ResultSetMetaData to be able to return the column name as the key in the Map.

164.3.1. Message Headers

HeaderDescription

CamelJdbcRowCount

If the query is a SELECT, query the row count is returned in this OUT header.

CamelJdbcUpdateCount

If the query is an UPDATE, query the update count is returned in this OUT header.

CamelGeneratedKeysRows

Camel 2.10: Rows that contains the generated kets.

CamelGeneratedKeysRowCount

Camel 2.10: The number of rows in the header that contains generated keys.

CamelJdbcColumnNames

Camel 2.11.1: The column names from the ResultSet as a java.util.Set type.

CamelJdbcParametes

Camel 2.12: A java.util.Map which has the headers to be used if useHeadersAsParameters has been enabled.

164.4. Generated keys

Available as of Camel 2.10

If you insert data using SQL INSERT, then the RDBMS may support auto generated keys. You can instruct the JDBC producer to return the generated keys in headers.
To do that set the header CamelRetrieveGeneratedKeys=true. Then the generated keys will be provided as headers with the keys listed in the table above.

You can see more details in this unit test.

Using generated keys does not work with together with named parameters.

164.5. Using named parameters

Available as of Camel 2.12

In the given route below, we want to get all the projects from the projects table. Notice the SQL query has 2 named parameters, :?lic and :?min.
Camel will then lookup these parameters from the message headers. Notice in the example above we set two headers with constant value
for the named parameters:

  from("direct:projects")
     .setHeader("lic", constant("ASF"))
     .setHeader("min", constant(123))
     .setBody("select * from projects where license = :?lic and id > :?min order by id")
     .to("jdbc:myDataSource?useHeadersAsParameters=true")

You can also store the header values in a java.util.Map and store the map on the headers with the key CamelJdbcParameters.

164.6. Samples

In the following example, we fetch the rows from the customer table.

First we register our datasource in the Camel registry as testdb:

Then we configure a route that routes to the JDBC component, so the SQL will be executed. Note how we refer to the testdb datasource that was bound in the previous step:

Or you can create a DataSource in Spring like this:

We create an endpoint, add the SQL query to the body of the IN message, and then send the exchange. The result of the query is returned in the OUT body:

If you want to work on the rows one by one instead of the entire ResultSet at once you need to use the Splitter EIP such as:

In Camel 2.13.x or older

In Camel 2.14.x or newer

from("direct:hello")
// here we split the data from the testdb into new messages one by one
// so the mock endpoint will receive a message per row in the table
// the StreamList option allows to stream the result of the query without creating a List of rows
// and notice we also enable streaming mode on the splitter
.to("jdbc:testdb?outputType=StreamList")
  .split(body()).streaming()
  .to("mock:result");

164.7. Sample - Polling the database every minute

If we want to poll a database using the JDBC component, we need to combine it with a polling scheduler such as the Timer or Quartz etc. In the following example, we retrieve data from the database every 60 seconds:

from("timer://foo?period=60000").setBody(constant("select * from customer")).to("jdbc:testdb").to("activemq:queue:customers");

164.8. Sample - Move Data Between Data Sources

A common use case is to query for data, process it and move it to another data source (ETL operations). In the following example, we retrieve new customer records from the source table every hour, filter/transform them and move them to a destination table:

from("timer://MoveNewCustomersEveryHour?period=3600000")
    .setBody(constant("select * from customer where create_time > (sysdate-1/24)"))
    .to("jdbc:testdb")
    .split(body())
        .process(new MyCustomerProcessor()) //filter/transform results as needed
        .setBody(simple("insert into processed_customer values('${body[ID]}','${body[NAME]}')"))
        .to("jdbc:testdb");
 

164.9. See Also

  • Configuring Camel
  • Component
  • Endpoint
  • Getting Started
  • SQL