Mybatis-spring a DAO-level authoring issue from upgrading from 1.1 to 1.2

Our company's projects use Spring+mybatis combination. So we have to use the mybatis-spring. So here's a summary of the DAO-level writing problem that mybatis-spring from 1.1 to 1.2 yesterday.

Let's take a look at the code for Sqlsessiondaosupport in the 1.1.1 version of the mybatis-spring framework:

1  PackageOrg.mybatis.spring.support;2  3 Import Staticorg.springframework.util.assert.*;4  5 Importorg.apache.ibatis.session.SqlSession;6 Importorg.apache.ibatis.session.SqlSessionFactory;7 Importorg.mybatis.spring.SqlSessionTemplate;8 Importorg.springframework.beans.factory.annotation.Autowired;9 ImportOrg.springframework.dao.support.DaoSupport;Ten   One /** A * Convenient Super class for MyBatis sqlsession data Access objects. - * It gives you access to the template which can and be used to execute SQL methods. - * <p> the * This class needs a sqlsessiontemplate or a sqlsessionfactory. - * If Both is set the sqlsessionfactory would be ignored. -  * -  * @see#setSqlSessionFactory +  * @see#setSqlSessionTemplate -  * @seesqlsessiontemplate +  * @version$Id: Sqlsessiondaosupport.java 4885 2012-03-12 09:58:54z Simone.tripodi $ A  */ at  Public Abstract classSqlsessiondaosupportextendsDaosupport { -   -   Privatesqlsession sqlsession; -   -   Private Booleanexternalsqlsession; -   in@Autowired (required =false) -    Public Final voidsetsqlsessionfactory (sqlsessionfactory sqlsessionfactory) { to     if(! This. Externalsqlsession) { +        This. sqlsession =Newsqlsessiontemplate (sqlsessionfactory); -     } the   } *   $@Autowired (required =false)Panax Notoginseng    Public Final voidsetsqlsessiontemplate (sqlsessiontemplate sqlsessiontemplate) { -      This. sqlsession =sqlsessiontemplate; the      This. externalsqlsession =true; +   } A   the   /** + * Users should use the This method to get a sqlsession to call its statement methods - * This is sqlsession are managed by spring. Users should not commit/rollback/close it $ * because it 'll be is automatically done. $    * -    * @returnSpring Managed thread safe sqlsession -    */ the    Public Finalsqlsession getsqlsession () { -     return  This. sqlsession;Wuyi   } the   -   /** Wu    * {@inheritDoc} -    */ About   protected voidCheckdaoconfig () { $Notnull ( This. Sqlsession, "Property ' sqlsessionfactory ' or ' sqlsessiontemplate ' is required"); -   } -   -}

From the above source can be seen: in the method Setsqlsessionfactory and Setsqlsessiontemplate methods are marked with: "@Autowired (required = false)" such annotations.

So when we write the DAO level code, we only need DAO to inherit sqlsessiondaosupport directly, and annotate annotation @repository, then we can use similar getsqlsession (). SelectList (" User.selectusers "); This is the way to use it, and there are fewer configurations in the spring configuration file:

1<tx:annotation-driven transaction-manager= "Txmanager"2proxy-target-class= "true"/>3  4<bean id= "Txmanager"class= "Org.springframework.jdbc.datasource.DataSourceTransactionManager" >5<property name= "DataSource" ref= "DataSource"/>6</bean>7  8<bean id= "Sqlsessionfactory"class= "Org.mybatis.spring.SqlSessionFactoryBean" >9<property name= "DataSource" ref= "DataSource"/>Ten<property name= "configlocation" value= "Classpath:mybatis-config.xml"/> One</bean>

But after upgrading to 1.2, let's look at the source code for Sqlsessiondaosupport:

1  Public Abstract classSqlsessiondaosupportextendsDaosupport {2  3   Privatesqlsession sqlsession;4  5   Private Booleanexternalsqlsession;6  7    Public voidsetsqlsessionfactory (sqlsessionfactory sqlsessionfactory) {8     if(! This. Externalsqlsession) {9        This. sqlsession =Newsqlsessiontemplate (sqlsessionfactory);Ten     } One   } A   -    Public voidsetsqlsessiontemplate (sqlsessiontemplate sqlsessiontemplate) { -      This. sqlsession =sqlsessiontemplate; the      This. externalsqlsession =true; -   } -   -   /** + * Users should use the This method to get a sqlsession to call its statement methods - * This is sqlsession are managed by spring. Users should not commit/rollback/close it + * because it 'll be is automatically done. A    * at    * @returnSpring Managed thread safe sqlsession -    */ -    Publicsqlsession getsqlsession () { -     return  This. sqlsession; -   } -   in   /** -    * {@inheritDoc} to    */ +   protected voidCheckdaoconfig () { -Notnull ( This. Sqlsession, "Property ' sqlsessionfactory ' or ' sqlsessiontemplate ' is required"); the   } *   $}

From the above source can be seen: in the method Setsqlsessionfactory and Setsqlsessiontemplate methods are not labeled Now: "@Autowired (required = false)" such annotations.

Problems can occur if some systems are upgraded directly from mybatis-spring1.1.1 to version 1.2.

There are several ways to use it under version 1.2:

From the above source can be seen: in the method Setsqlsessionfactory and Setsqlsessiontemplate methods are not labeled Now: "@Autowired (required = false)" such annotations.

Problems can occur if some systems are upgraded directly from mybatis-spring1.1.1 to version 1.2.

There are several ways to use it under version 1.2:

1 @Repository2  Public classUserdaoextendssqlsessiondaosupport{3      PublicList<user>userlist () {4         returnGetsqlsession (). SelectList ("User.selectusers");5     }6  7 @Override8 @Autowired9      Public voidsetsqlsessionfactory (sqlsessionfactory sqlsessionfactory) {Ten         Super. Setsqlsessionfactory (sqlsessionfactory); One     } A}

We can rewrite the set method ourselves. In this scenario, the spring configuration file does not need to be modified. This example is arbitrary, if you have a lot of DAO classes in your project (most of the cases are), so you can write a Basedao, and then rewrite the method in this Basedao, the other DAO only need to inherit this Basedao.

The second chapter is based on the XML file configuration:

1  Public class extends Sqlsessiondaosupport {2      Public List<user> userlist () {3         return getsqlsession (). SelectList (" User.selectusers "); 4     }5 }

However, this Userdao configuration needs to be added to the spring configuration file:

1 class= "Com.qunar.corp.paginator.dao.UserDao" >2     <property name= "Sqlsessionfactory" ref= "Sqlsessionfactory"/>3 </bean>

The first annotation-based configuration has the advantage of not having to write XML, but this comparison is easy to hack into business logic.

The second, XML-based configuration, has the advantage of not intruding into business logic, but when there is a large number of DAO, it needs to be configured in XML.

So the final specific choice of which, we can combine their own situation.

Mybatis-spring a DAO-level authoring issue from upgrading from 1.1 to 1.2