因为spring 整合mybatis的过程中， 有好几种整合方式，尤其是数据源那块，经常看到不一样的配置方式，总感觉有点乱，所以今天有空总结下。
一、采用org.mybatis.spring.mapper.MapperScannerConfigurer
其实逆向工程也是这种方式
1、数据源配配置文件
2、DAO文件
package com.jdd.mapper;
import com.jdd.pojo.Employee;
import java.util.List;
public interface EmployeeMapper {
public Employee getEmployeeById(int id);
public List<Employee> findAllEmployees();
}
3、Mapper.xml 文件
<?xml version="." encoding="UTF-" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper .//EN"
"http://mybatis.org/dtd/mybatis--mapper.dtd">
<mapper namespace="com.jdd.mapper.EmployeeMapper">
<select id="getEmployeeById" parameterType="int" resultType="com.jdd.pojo.Employee">
<![CDATA[
select * from employee where id = #{id};
]]>
</select>
<select id="findAllEmployees" resultType="com.jdd.pojo.Employee">
<![CDATA[
select * from employee where status='';
]]>
</select>
</mapper>
这样在service类里就可以直接注入dao接口了
package com.jdd.service.impl;
import com.jdd.mapper.EmployeeMapper;
import com.jdd.pojo.Employee;
import com.jdd.service.EmployeeService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service("employeeService")
public class EmployeeServiceImpl implements EmployeeService{
@Autowired
private EmployeeMapper employeeMapper;
@Override
public Employee getEmployeeById(int id) {
return employeeMapper.getEmployeeById(id);
}
@Override
public List<Employee> findAllEmployees() {
return employeeMapper.findAllEmployees();
}
}
二、 采用抽象类org.mybatis.spring.support.SqlSessionDaoSupport， 给它注入 sqlSessionFactory的方式
1、数据源配置文件
<?xml version="." encoding="UTF-"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:xsi="http://www.w.org//XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-..xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-..xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-..xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-..xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-..xsd">
<!-- 加载配置文件 -->
<context:property-placeholder location="classpath:resource/*.properties" />
<!-- 数据库连接池 -->
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
destroy-method="close">
<property name="driverClassName" value="${jdbc.driver}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
<property name="maxActive" value="" />
<property name="minIdle" value="" />
</bean>
<!-- sqlsessionFactory -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="configLocation" value="classpath:mybatis/SqlMapConfig.xml"></property>
<property name="dataSource" ref="dataSource"></property>
<property name="mapperLocations" value="classpath:com/jdd/mapper/*.xml"></property>
</bean>
</beans>
2、baseDao类
package com.jdd.dao;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.support.SqlSessionDaoSupport;
import javax.annotation.Resource;
public abstract class BaseDao extends SqlSessionDaoSupport {
@Resource
public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
super.setSqlSessionFactory(sqlSessionFactory);
}
}
3、接口 EmployeeDao.java 类
package com.jdd.dao;
import com.jdd.pojo.Employee;
import java.util.List;
public interface EmployeeDao {
Employee getEmployeeById(int id);
List<Employee> findAllEmployees();
}
4、dao实现类 EmployeeDaoImpl
package com.jdd.dao.impl;
import com.jdd.dao.BaseDao;
import com.jdd.dao.EmployeeDao;
import com.jdd.pojo.Employee;
import org.springframework.stereotype.Repository;
import java.util.List;
@Repository("employeeDao")
public class EmployeeDaoImpl extends BaseDao implements EmployeeDao {
@Override
public Employee getEmployeeById(int id) {
return this.getSqlSession().selectOne("com.jdd.dao.EmployeeDao.getEmployeeById", id);
}
@Override
public List<Employee> findAllEmployees() {
return this.getSqlSession().selectList("com.jdd.dao.EmployeeDao.findAllEmployees");
}
}
5、这样就可以在service类里注入 employeeDao了
三、采用 org.mybatis.spring.SqlSessionTemplate 模板类
1、数据源文件
<?xml version="." encoding="UTF-"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:xsi="http://www.w.org//XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-..xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-..xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-..xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-..xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-..xsd">
<!-- 加载配置文件 -->
<context:property-placeholder location="classpath:resource/*.properties" />
<!-- 数据库连接池 -->
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
destroy-method="close">
<property name="driverClassName" value="${jdbc.driver}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
<property name="maxActive" value="" />
<property name="minIdle" value="" />
</bean>
<!-- sqlsessionFactory -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="configLocation" value="classpath:mybatis/SqlMapConfig.xml"></property>
<property name="dataSource" ref="dataSource"></property>
<property name="mapperLocations" value="classpath:com/jdd/mapper/*.xml"></property>
</bean>
<bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
<constructor-arg index="" ref="sqlSessionFactory"/>
</bean>
</beans>
2、 basedao.java 类
package com.jdd.dao;
import org.mybatis.spring.SqlSessionTemplate;
import javax.annotation.Resource;
public abstract class BaseDao {
public SqlSessionTemplate sqlSessionTemplate;
@Resource
public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {
this.sqlSessionTemplate = sqlSessionTemplate;
}
}
3、接口 EmployeeDao.java 类
package com.jdd.dao;
import com.jdd.pojo.Employee;
import java.util.List;
public interface EmployeeDao {
Employee getEmployeeById(int id);
List<Employee> findAllEmployees();
}
4、dao实现类 EmployeeDaoImpl
package com.jdd.dao.impl;
import com.jdd.dao.BaseDao;
import com.jdd.dao.EmployeeDao;
import com.jdd.pojo.Employee;
import org.springframework.stereotype.Repository;
import java.util.List;
@Repository("employeeDao")
public class EmployeeDaoImpl extends BaseDao implements EmployeeDao {
@Override
public Employee getEmployeeById(int id) {
return sqlSessionTemplate.selectOne("com.jdd.dao.EmployeeDao.getEmployeeById", id);
}
@Override
public List<Employee> findAllEmployees() {
return sqlSessionTemplate.selectList("com.jdd.dao.EmployeeDao.findAllEmployees");
}
}
5、同样现在也可以在service类里直接注入 employeeDao使用了。
注：这里basedao的注入比较灵活，也可以注入 SqlSessionFactory， 然后再setter方法里创建 SqlSessionTemplate，如下：
package com.jdd.dao;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionTemplate;
import javax.annotation.Resource;
public abstract class BaseDao {
public SqlSessionTemplate sqlSessionTemplate;
@Resource
public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
sqlSessionTemplate = new SqlSessionTemplate(sqlSessionFactory);
}
}
其实不管是采用 继承SqlSessionDaoSupport类， 注入 sqlSessionFactory的方式， 还是直接注入 SqlSessionTemplate 的方式， 本质上是一样的。
如果你采用 注入 sqlSessionFactory的方式， 它在底层也是通过sqlSessionFactory 来创建 SqlSessionTemplate ，然后通过其api来操作。
不信给你们看下 SqlSessionDaoSupport 的源码：
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//
package org.mybatis.spring.support;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionTemplate;
import org.springframework.dao.support.DaoSupport;
import org.springframework.util.Assert;
public abstract class SqlSessionDaoSupport extends DaoSupport {
private SqlSession sqlSession;
private boolean externalSqlSession;
public SqlSessionDaoSupport() {
}
public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
if (!this.externalSqlSession) {
this.sqlSession = new SqlSessionTemplate(sqlSessionFactory);
}
}
public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {
this.sqlSession = sqlSessionTemplate;
this.externalSqlSession = true;
}
public SqlSession getSqlSession() {
return this.sqlSession;
}
protected void checkDaoConfig() {
Assert.notNull(this.sqlSession, "Property 'sqlSessionFactory' or 'sqlSessionTemplate' are required");
}
}
同样 SqlSessionTemplate 继承了 SqlSession 接口， 因此不管操作哪个效果都一样
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//
package org.mybatis.spring;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.sql.Connection;
import java.util.List;
import java.util.Map;
import org.apache.ibatis.exceptions.PersistenceException;
import org.apache.ibatis.executor.BatchResult;
import org.apache.ibatis.reflection.ExceptionUtil;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.ExecutorType;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.springframework.dao.support.PersistenceExceptionTranslator;
import org.springframework.util.Assert;
public class SqlSessionTemplate implements SqlSession {
private final SqlSessionFactory sqlSessionFactory;
private final ExecutorType executorType;
private final SqlSession sqlSessionProxy;
private final PersistenceExceptionTranslator exceptionTranslator;
public SqlSessionTemplate(SqlSessionFactory sqlSessionFactory) {
this(sqlSessionFactory, sqlSessionFactory.getConfiguration().getDefaultExecutorType());
}
public SqlSessionTemplate(SqlSessionFactory sqlSessionFactory, ExecutorType executorType) {
this(sqlSessionFactory, executorType, new MyBatisExceptionTranslator(sqlSessionFactory.getConfiguration().getEnvironment().getDataSource(), true));
}
public SqlSessionTemplate(SqlSessionFactory sqlSessionFactory, ExecutorType executorType, PersistenceExceptionTranslator exceptionTranslator) {
Assert.notNull(sqlSessionFactory, "Property 'sqlSessionFactory' is required");
Assert.notNull(executorType, "Property 'executorType' is required");
this.sqlSessionFactory = sqlSessionFactory;
this.executorType = executorType;
this.exceptionTranslator = exceptionTranslator;
this.sqlSessionProxy = (SqlSession)Proxy.newProxyInstance(SqlSessionFactory.class.getClassLoader(), new Class[]{SqlSession.class}, new SqlSessionTemplate.SqlSessionInterceptor());
}
public SqlSessionFactory getSqlSessionFactory() {
return this.sqlSessionFactory;
}
public ExecutorType getExecutorType() {
return this.executorType;
}
public PersistenceExceptionTranslator getPersistenceExceptionTranslator() {
return this.exceptionTranslator;
}
public <T> T selectOne(String statement) {
return this.sqlSessionProxy.selectOne(statement);
}
public <T> T selectOne(String statement, Object parameter) {
return this.sqlSessionProxy.selectOne(statement, parameter);
}
public <K, V> Map<K, V> selectMap(String statement, String mapKey) {
return this.sqlSessionProxy.selectMap(statement, mapKey);
}
public <K, V> Map<K, V> selectMap(String statement, Object parameter, String mapKey) {
return this.sqlSessionProxy.selectMap(statement, parameter, mapKey);
}
public <K, V> Map<K, V> selectMap(String statement, Object parameter, String mapKey, RowBounds rowBounds) {
return this.sqlSessionProxy.selectMap(statement, parameter, mapKey, rowBounds);
}
public <E> List<E> selectList(String statement) {
return this.sqlSessionProxy.selectList(statement);
}
public <E> List<E> selectList(String statement, Object parameter) {
return this.sqlSessionProxy.selectList(statement, parameter);
}
public <E> List<E> selectList(String statement, Object parameter, RowBounds rowBounds) {
return this.sqlSessionProxy.selectList(statement, parameter, rowBounds);
}
public void select(String statement, ResultHandler handler) {
this.sqlSessionProxy.select(statement, handler);
}
public void select(String statement, Object parameter, ResultHandler handler) {
this.sqlSessionProxy.select(statement, parameter, handler);
}
public void select(String statement, Object parameter, RowBounds rowBounds, ResultHandler handler) {
this.sqlSessionProxy.select(statement, parameter, rowBounds, handler);
}
public int insert(String statement) {
return this.sqlSessionProxy.insert(statement);
}
public int insert(String statement, Object parameter) {
return this.sqlSessionProxy.insert(statement, parameter);
}
public int update(String statement) {
return this.sqlSessionProxy.update(statement);
}
public int update(String statement, Object parameter) {
return this.sqlSessionProxy.update(statement, parameter);
}
public int delete(String statement) {
return this.sqlSessionProxy.delete(statement);
}
public int delete(String statement, Object parameter) {
return this.sqlSessionProxy.delete(statement, parameter);
}
public <T> T getMapper(Class<T> type) {
return this.getConfiguration().getMapper(type, this);
}
public void commit() {
throw new UnsupportedOperationException("Manual commit is not allowed over a Spring managed SqlSession");
}
public void commit(boolean force) {
throw new UnsupportedOperationException("Manual commit is not allowed over a Spring managed SqlSession");
}
public void rollback() {
throw new UnsupportedOperationException("Manual rollback is not allowed over a Spring managed SqlSession");
}
public void rollback(boolean force) {
throw new UnsupportedOperationException("Manual rollback is not allowed over a Spring managed SqlSession");
}
public void close() {
throw new UnsupportedOperationException("Manual close is not allowed over a Spring managed SqlSession");
}
public void clearCache() {
this.sqlSessionProxy.clearCache();
}
public Configuration getConfiguration() {
return this.sqlSessionFactory.getConfiguration();
}
public Connection getConnection() {
return this.sqlSessionProxy.getConnection();
}
public List<BatchResult> flushStatements() {
return this.sqlSessionProxy.flushStatements();
}
private class SqlSessionInterceptor implements InvocationHandler {
private SqlSessionInterceptor() {
}
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
SqlSession sqlSession = SqlSessionUtils.getSqlSession(SqlSessionTemplate.this.sqlSessionFactory, SqlSessionTemplate.this.executorType, SqlSessionTemplate.this.exceptionTranslator);
Object unwrapped;
try {
Object result = method.invoke(sqlSession, args);
if (!SqlSessionUtils.isSqlSessionTransactional(sqlSession, SqlSessionTemplate.this.sqlSessionFactory)) {
sqlSession.commit(true);
}
unwrapped = result;
} catch (Throwable var) {
unwrapped = ExceptionUtil.unwrapThrowable(var);
if (SqlSessionTemplate.this.exceptionTranslator != null && unwrapped instanceof PersistenceException) {
SqlSessionUtils.closeSqlSession(sqlSession, SqlSessionTemplate.this.sqlSessionFactory);
sqlSession = null;
Throwable translated = SqlSessionTemplate.this.exceptionTranslator.translateExceptionIfPossible((PersistenceException)unwrapped);
if (translated != null) {
unwrapped = translated;
}
}
throw (Throwable)unwrapped;
} finally {
if (sqlSession != null) {
SqlSessionUtils.closeSqlSession(sqlSession, SqlSessionTemplate.this.sqlSessionFactory);
}
}
return unwrapped;
}
}
}
总结
以上所述是小编给大家介绍的spring 整合 mybatis 中数据源的几种配置方式，希望对大家有所帮助，如果大家有任何疑问欢迎给我留言，小编会及时回复大家的！
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