The jdbc component enables you to access databases through JDBC, where SQL queries and operations are sent in the message body. This component uses the standard JDBC API, unlike the SQL Component component, which uses spring-jdbc.
Maven users 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>
![]() | Warning |
---|---|
This component can only be used to define producer endpoints,
which means that you cannot use the JDBC component in a
|
![]() | Important |
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This component cannot be used as a transactional client. If you need transaction support in your route, use the SQL Component component instead. |
jdbc:dataSourceName[?options]
This component supports producer endpoints only.
You can append query options to the URI in the following format,
?option=value&option=value&...
Name | Default Value | Description |
---|---|---|
readSize
|
0 / 2000
|
The default maximum number of rows that can be read by a polling query. The default value is 2000 for Apache Camel 1.5.0 or older. In newer releases the default value is 0. |
statement.<xxx>
|
null
|
Apache Camel 2.1: Sets
additional options on the
java.sql.Statement that is used
behind the scenes to execute the queries. For instance,
statement.maxRows=10 . For detailed
documentation, see the java.sql.Statement
javadoc documentation. |
useJDBC4ColumnNameAndLabelSemantics
|
true
|
Apache Camel 2.2: Sets
whether to use JDBC 4/3 column label/name semantics. You can
use this option to turn it false in case
you have issues with your JDBC driver to select data. This
only applies when using SQL SELECT using
aliases (e.g. SQL SELECT id as identifier, name as
given_name from persons ). |
resetAutoCommit
|
true
|
Apache Camel 2.9: When
true , Camel sets the autoCommit flag
on the JDBC connection to false , commits
the change after executing the statement, and resets the
connection's autoCommit flag to true at
the end of the operation. If the JDBC connection does not
support resetting the autoCommit flag, set this option to
false to prevent Camel from trying to
set the connection's autoCommit flag. |
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.
![]() | Note |
---|---|
This component fetches |
Header | Description |
---|---|
CamelJdbcRowCount
|
If the query is a SELECT , the row count
is returned in this OUT header. |
CamelJdbcUpdateCount
|
If the query is an UPDATE , the update
count is returned in this OUT header. |
CamelGeneratedKeysRows
|
Apache Camel 2.10: Rows that contain the generated keys. |
CamelGeneratedKeysRowCount
|
Apache Camel 2.10: The number of rows in the header that contain generated keys. |
Available as of 2.10.
The RDBMS may support autogenerated keys if you insert data using
SQL INSERT. If so, you can instruct the JDBC producer to return the
generated keys in headers. To do so, set the header
CamelRetrieveGenerateKeys=true
, and then the
generated keys will be returned as headers with the keys listed in
Message Headers.
In the following example, we fetch the rows from the customer table.
First we register our datasource in the Apache Camel registry as
testdb
:
JndiRegistry reg = super.createRegistry(); reg.bind("testdb", ds); return reg;
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:
// lets add simple route public void configure() throws Exception { from("direct:hello").to("jdbc:testdb?readSize=100"); }
Or you can create a DataSource
in Spring like
this:
<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="timer://kickoff?period=10000"/> <setBody> <constant>select * from customer</constant> </setBody> <to uri="jdbc:testdb"/> <to uri="mock:result"/> </route> </camelContext> <!-- Just add a demo to show how to bind a date source for camel in Spring--> <bean id="testdb" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="org.hsqldb.jdbcDriver"/> <property name="url" value="jdbc:hsqldb:mem:camel_jdbc" /> <property name="username" value="sa" /> <property name="password" value="" /> </bean>
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:
// first we create our exchange using the endpoint Endpoint endpoint = context.getEndpoint("direct:hello"); Exchange exchange = endpoint.createExchange(); // then we set the SQL on the in body exchange.getIn().setBody("select * from customer order by ID"); // now we send the exchange to the endpoint, and receives the response from Camel Exchange out = template.send(endpoint, exchange); // assertions of the response assertNotNull(out); assertNotNull(out.getOut()); ArrayList<HashMap<String, Object>> data = out.getOut().getBody(ArrayList.class); assertNotNull("out body could not be converted to an ArrayList - was: " + out.getOut().getBody(), data); assertEquals(2, data.size()); HashMap<String, Object> row = data.get(0); assertEquals("cust1", row.get("ID")); assertEquals("jstrachan", row.get("NAME")); row = data.get(1); assertEquals("cust2", row.get("ID")); assertEquals("nsandhu", row.get("NAME"));
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:
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 .to("jdbc:testdb").split(body()).to("mock:result");
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");
See also: