MyBatis

MyBatis

Available as of Camel 2.7

The mybatis: component allows you to query, poll, insert, update and delete data in a relational database using MyBatis.

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

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

URI format

mybatis:statementName[?options]

Where statementName is the statement name in the MyBatis XML mapping file which maps to the query, insert, update or delete operation you wish to evaluate.

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

This component will by default load the MyBatis SqlMapConfig file from the root of the classpath and expected named as SqlMapConfig.xml.
If the file is located in another location, you would have to configure the configurationUri option on the MyBatisComponent component.

Options

Message Headers

Camel will populate the result message, either IN or OUT with a header with the statement used:

Message Body

The response from MyBatis will only be set as body if it's a SELECT statement. That means, for example, for INSERT statements Camel will not replace the body. This allows you to continue routing and keep the original body. The response from MyBatis is always stored in the header with the key CamelMyBatisResult.

Samples

For example if you wish to consume beans from a JMS queue and insert them into a database you could do the following:

from("activemq:queue:newAccount").
  to("mybatis:insertAccount?statementType=Insert");

Notice we have to specify the statementType, as we need to instruct Camel which kind of operation to invoke.

Where insertAccount is the MyBatis ID in the SQL mapping file:

  <!-- Insert example, using the Account parameter class -->
  <insert id="insertAccount" parameterType="Account">
    insert into ACCOUNT (
      ACC_ID,
      ACC_FIRST_NAME,
      ACC_LAST_NAME,
      ACC_EMAIL
    )
    values (
      #{id}, #{firstName}, #{lastName}, #{emailAddress}
    )
  </insert>

Using StatementType for better control of MyBatis

When routing to an MyBatis endpoint you want more fine grained control so you can control whether the SQL statement to be executed is a SELEECT, UPDATE, DELETE or INSERT etc. So for instance if we want to route to an MyBatis endpoint in which the IN body contains parameters to a SELECT statement we can do:

In the code above we can invoke the MyBatis statement selectAccountById and the IN body should contain the account id we want to retrieve, such as an Integer type.

We can do the same for some of the other operations, such as SelectList:

And the same for UPDATE, where we can send an Account object as IN body to MyBatis:

Scheduled polling example

Since this component does not support scheduled polling, you need to use another mechanism for triggering the scheduled polls, such as the Timer or Quartz components.

In the sample below we poll the database, every 30 seconds using the Timer component and send the data to the JMS queue:

from("timer://pollTheDatabase?delay=30000").to("mbatis:selectAllAccounts").to("activemq:queue:allAccounts");

And the MyBatis SQL mapping file used:

  <!-- Select with no parameters using the result map for Account class. -->
  <select id="selectAllAccounts" resultMap="AccountResult">
    select * from ACCOUNT
  </select>

Using onConsume

This component supports executing statements after data have been consumed and processed by Camel. This allows you to do post updates in the database. Notice all statements must be UPDATE statements. Camel supports executing multiple statements whose name should be separated by comma.

The route below illustrates we execute the consumeAccount statement data is processed. This allows us to change the status of the row in the database to processed, so we avoid consuming it twice or more.

And the statements in the sqlmap file:

See Also

• Configuring Camel
• Component
• Endpoint
• Getting Started