THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
JDBC Component
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 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.
This component can not be used as a Transactional Client. If you need transaction support in your route, you should use the SQL component instead.
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&...
Options
Name |
Default Value |
Description |
|---|---|---|
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The default maximum number of rows that can be read by a polling query. The default value is 0. |
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Camel 2.1: Sets additional options on the |
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Camel 2.2: Sets whether to use JDBC 4/3 column label/name semantics. You can use this option to turn it |
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Camel 2.9: 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. |
Result
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 ResultSetMetaData to be able to return the column name as the key in the Map.
Message Headers
Header |
Description |
|---|---|
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If the query is a |
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If the query is an |
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Camel 2.10: Rows that contains the generated kets. |
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Camel 2.10: The number of rows in the header that contains generated keys. |
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Camel 2.11.1: The column names from the ResultSet as a |
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.
Samples
In the following example, we fetch the rows from the customer table.
First we register our datasource in the Camel registry as testdb:
Error formatting macro: snippet: java.lang.NullPointerException
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:
Error formatting macro: snippet: java.lang.NullPointerException
Or you can create a DataSource in Spring like this:
Error formatting macro: snippet: java.lang.NullPointerException
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:
Error formatting macro: snippet: java.lang.NullPointerException
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:
Error formatting macro: snippet: java.lang.NullPointerException
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");