Let’s look at a simple example to see how we can integrate MyBatis in Spring Application.
Maven POM for the demo –
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.mms.blogs</groupId> <artifactId>MyBatisSpringDemo</artifactId> <version>1.0.0-SNAPSHOT</version> <packaging>war</packaging> <name>MyBatisSpringDemo</name> <dependencies> <dependency> <groupId>org.mybatis</groupId> <artifact Id>mybatis-spring</artifactId> <version>1.1.1</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.10</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>3.2.0.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-tx</artifactId> <version>3.2.0.RELEASE</version> </dependency> <dependency> <groupId>org.hsqldb</groupId> <artifactId>hsqldb</artifactId> <version>2.2.9</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>3.2.0.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>3.2.0.RELEASE</version> </dependency> </dependencies> </project>
MyBatis Mapper –
MyBatis is driven by a Mapper Interface that defines the methods to interact against database. SQL mapping code is defined in a xml file defined by the same name of the Mapper Interface.
Mapping to work correctly, below three things should match for each mapper –
- Interface file name and package
- Xml file name and its location should be same as Interface.
- namespace in xml file.
EmployeeMapper.java –
package com.mms.blogs.demo.mybatisspring.mapper; import com.mms.blogs.demo.mybatisspring.vo.Employee; public interface EmployeeMapper { public Employee getEmployeeName(long empId); public void insertEmployee(Employee employee); }
EmployeeMapper.xml –
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="com.mms.blogs.demo.mybatisspring.mapper.EmployeeMapper"> <select id="getEmployeeName" parameterType="long" resultType="com.mms.blogs.demo.mybatisspring.vo.Employee"> SELECT empid, first_name firstName,last_name lastName from employee where empid=#{empid} </select> <insert id="insertEmployee" parameterType="com.mms.blogs.demo.mybatisspring.vo.Employee"> insert into employee (empid,first_name,last_name) values (#{empid},#{firstName},#{lastName}) </insert> </mapper>
Employee.java – VO Object
package com.mms.blogs.demo.mybatisspring.vo; import org.springframework.stereotype.Component; @Component public class Employee { private long empid; private String firstName; private String lastName; public long getEmpid() { return empid; } public void setEmpid(long empid) { this.empid = empid; } public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } }
Spring Application Context –
Following is the application context for this demo –
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd"> <context:annotation-config/> <context:component-scan base-package="com.mms.blogs.demo.mybatisspring"></context:component-scan> <jdbc:embedded-database id="dataSource"> <jdbc:script location="classpath:schema.sql"/> </jdbc:embedded-database> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/> </bean> <bean class="org.mybatis.spring.SqlSessionFactoryBean" id="sqlSessionFactory"> <property name="dataSource" ref="dataSource"/> </bean> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/> <property name="basePackage" value="com.mms.blogs.demo.mybatisspring.mapper"/> </bean> </beans>
- Enable annotation config to Autowire our Spring configuration and also Autowire MyBatis mappers where ever needed.
- component-scan provides base package to look for components.
- TransactionManager to handle transactions
- Spring’s embedded database instance. This loads the sample teable Employee into embedded database using sql defined in compile.sql script.
- Bean for org.mybatis.spring.SqlSessionFactoryBean to configure the datasource.
- MapperScannerConfigurer – This class initializes a bean for each of the mapper interface defined in basePackage and injects sqlSessionFactory instance in it. This enables Autowiring of the mapper interfaces in code.
Schema.sql –
create table employee(
empid BIGINT,
first_name varchar(50),
last_name varchar(50)
);
So with all above configuration MyBatis is now integrated with Spring. Let’s write a simple JUnit to test our integration –
package com.mms.blogs.demo.mybatisspring.mapper; import junit.framework.Assert; import org.junit.Before; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.AbstractTransactionalJUnit4SpringContextTests; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; import com.mms.blogs.demo.mybatisspring.vo.Employee; @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(value={"classpath:applicationContext.xml"}) public class EmployeeTest extends AbstractTransactionalJUnit4SpringContextTests { @Autowired private EmployeeMapper employeeMapper; @Before public void insertEmployee(){ Employee emp = new Employee(); emp.setEmpid(1); emp.setFirstName("Manik"); emp.setLastName("Magar"); employeeMapper.insertEmployee(emp); } @Test public void testEmployee(){ System.out.println("testEmployee"); Employee emp = employeeMapper.getEmployeeName(1); Assert.assertNotNull(emp); } }
Cheers!
Where is the source? … It’s here
References
