user1094865
user1094865

Reputation:

Tomcat connection pool with MyBatis

I was wondering if anyone has any code examples for setting up a connection pool in Tomcat (7 or later) using MyBatis as the ORM.

I presume I need to add a resource to my context.xml file in my Tomcat conf folder and then link that to MyBatis. I've had a look and any tutorials I have found seem to be Spring specific. Does anyone have a simple tutorial or can they outline the steps required to get this up and running?

Upvotes: 4

Views: 6599

Answers (2)

zafar142003
zafar142003

Reputation: 2159

There are a number of ways you can do this. I am assuming that you mean to implement Tomcat (as opposed to Spring) managed connection pooling. I have tested on MySQl/Spring 4/Mybatis-spring 1.1 stack.

  1. Figure out the connection pooling mechanism you want to implement (C3P0/DBCP etc).

  2. If you want to use your database as a JNDI data source, then you have to declare it as a resource in Tomcat settings. There are a number of ways to do this. You can follow this well written guide Tomcat JNDI connection pooling. I generally add the following entry in context.xml located in the META-INF directory of my app:

<Context> <Resource name="jdbc/TestDB" auth="Container" type="javax.sql.DataSource" maxTotal="100" maxIdle="30" maxWaitMillis="10000" username="javauser" password="javadude" driverClassName="com.mysql.jdbc.Driver" url="jdbc:mysql://localhost:3306/javatest"/> </Context>

This file is used by Tomcat to invoke its own default connection pool, which in this case would be DBCP 2. You can tweak its settings by adding more parameters (like removeAbandonedOnBorrow=true) in the Resource element above. You should put the driver jar (eg MySQL Connector Jar) of your database in Tomcat's lib folder.

  1. After this, depending on your Mybatis implementation (XML or bean based), you can inject this data source into Mybatis. If you are doing it the bean way, you can do it like this:

<bean id="dbDataSource" class="org.springframework.jndi.JndiObjectFactoryBean"> <property name="jndiName" value="java:comp/env/jdbc/TestDB"/> </bean> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dbDataSource" /> </bean> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dbDataSource" /> <property name="typeAliasesPackage" value="com.example.model"/> <property name="mapperLocations" value="classpath*:*.xml" /> </bean> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.example.dao" /> </bean>

MapperScannerConfigurer is necessary because it searches the directories given to it to find mapper xml files. You can also use the old way of defining a mybatis-config.xml file by injecting the file's location in the sqlSessionFactory bean in its configLocation property.

Upvotes: 0

Bogdan
Bogdan

Reputation: 24590

There is this old entry in the iBatis FAQ that should still be applicable to myBatis: How do I use a JNDI DataSource with iBATIS in Tomcat?.

You can google for the details to configure a datasource in your Tomcat version, then configure MyBatis as well (it's different than the iBatis configuration):

<environment id="development">
    <transactionManager type="JDBC" />
    <dataSource type="JNDI">
        <property name="data_source" value="java:comp/env/jdbc/yourDatasourceName"/>
    </dataSource>
</environment>

Upvotes: 4

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