【spring笔记】Spring整合Mybaties

• 官方文档：http://mybatis.org/spring/zh/sqlsession.html

1、实现方式1

核心思想：利用Spring配置依赖注入创建sqlSessionFactory和sqlSession实例

• 需要的包如下：

1.1、编写数据源

这个很简单，就是spring在包装了一下配置参数

1.2、创建sqlSessionFactory

对比Mybatis就是不用自己new对象了，框架都写好了，用配置问价注入容器

1.3、创建sqlSessionTemplate

其实就是创建一个sqlSession

1.4、给接口加实现类

为什么这里需要实现类呢？因为Mybatis不能自动生成类对象，所以需要我们手动写一个实现类，然后将上面的sqlSessioinTemplate注入进去

package com.wcy.mapper;

import com.wcy.pojo.Student;
import org.apache.ibatis.session.SqlSession;

import java.util.List;

public class StudentMapperImpl implements StudentMapper {

private SqlSessionTemplate sqlSession;

public void setSqlSession(SqlSessionTemplate sqlSession) {
    this.sqlSession = sqlSession;
}

@Override
public List<Student> getStudentList() {
    StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
    return studentMapper.getStudentList();
}

}

1.5、将自己写的实现类，注入到Spring中

1.6、测试

public class MyTest_spring_Mybatis {
    @Test
    public void test() {
        ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");
        StudentMapper studentMapper = context.getBean("studentMapper", StudentMapper.class);
        for(Student student : studentMapper.getStudentList()) {
            System.out.println(student.toString());
        }
    }
}

测试过程还发现一个问题
java.lang.NoSuchMethodError: org.springframework.beans.factory.config.BeanDefinition.get ResolvableType()Lorg/springframework/core/ResolvableType;
最后发现是springweb-mvc和sping-jdbc版本不一致导致的，统一就好了

2、实现方式2

方式二其实就是，sqlSession通过spring提供的类直接get出来

官网描述如下：

2.1、实现接口的类

package com.wcy.mapper;


import com.wcy.pojo.Student;
import org.apache.ibatis.session.SqlSession;
import org.mybatis.spring.support.SqlSessionDaoSupport;


import java.util.List;


public class StudentMapperImpl2 extends SqlSessionDaoSupport implements StudentMapper{


    @Override
    public List<Student> getStudentList() {
        return getSqlSession().getMapper(StudentMapper.class).getStudentList();
    }
}

配置参数里，因为是继承了SqlSessionDaoSupport类，所以直接注入sqlSessionFactory就好了

SqlSessionDaoSupport源码：

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 SqlSessionTemplate sqlSessionTemplate;

    public SqlSessionDaoSupport() {
    }

    public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
        if (this.sqlSessionTemplate == null || sqlSessionFactory != this.sqlSessionTemplate.getSqlSessionFactory()) {
            this.sqlSessionTemplate = this.createSqlSessionTemplate(sqlSessionFactory);
        }
    }
}

<bean id="studentMapper2" class="com.wcy.mapper.StudentMapperImpl2">
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
</bean>