这篇文章主要介绍了Mybatis基于注解开启使用二级缓存,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下
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本文主要是补充一下Mybatis中基于注解的二级缓存的开启使用方法。
1.在Mybatis的配置文件中开启二级缓存
<?xml version="1.0" encoding="UTF-8" ?>
开启缓存
2.领域类以及Dao
public class User implements Serializable{
private Integer userId;
private String userName;
private Date userBirthday;
private String userSex;
private String userAddress;
private List accounts;
省略get和set方法......
}
import com.example.domain.User;
import org.apache.ibatis.annotations.*;
import org.apache.ibatis.mapping.FetchType;
import java.util.List;
@CacheNamespace(blocking = true)
public interface UserDao {
/**
* 查找所有用户
* @return
*/
@Select("select * from User")
@Results(id = "userMap",value = {@Result(id = true,column = "id",property = "userId"),
@Result(column = "username",property = "userName"),
@Result(column = "birthday",property = "userBirthday"),
@Result(column = "sex",property = "userSex"),
@Result(column = "address",property = "userAddress"),
@Result(column = "id",property = "accounts",many = @Many(select = "com.example.dao.AccountDao.findAccountByUid",fetchType = FetchType.LAZY))
})
List findAll();
/**
* 保存用户
* @param user
*/
@Insert("insert into user(username,birthday,sex,address) values(#{username},#{birthday},#{sex},#{address})")
void saveUser(User user);
/**
* 更新用户
* @param user
*/
@Update("update user set username=#{username},birthday=#{birthday},sex=#{sex},address=#{address} where id=#{id}")
void updateUser(User user);
/**
* 删除用户
* @param id
*/
@Delete("delete from user where id=#{id}")
void deleteUser(Integer id);
/**
* 查询用户根据ID
* @param id
* @return
*/
@Select("select * from user where id=#{id}")
@ResultMap(value = {"userMap"})
User findById(Integer id);
/**
* 根据用户名称查询用户
* @param name
* @return
*/
// @Select("select * from user where username like #{name}")
@Select("select * from user where username like '%${value}%'")
List findByUserName(String name);
/**
* 查询用户数量
* @return
*/
@Select("select count(*) from user")
int findTotalUser();
} 3.在对应的Dao类上面增加注释以开启二级缓存
@CacheNamespace(blocking = true)
4.测试
public class UserCacheTest {
private InputStream in;
private SqlSessionFactory sqlSessionFactory;
@Before
public void init()throws Exception{
in = Resources.getResourceAsStream("SqlMapConfig.xml");
sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
}
@After
public void destory()throws Exception{
in.close();
}
@Test
public void testFindById(){
//第一查询
SqlSession sqlSession1 = sqlSessionFactory.openSession();
UserDao userDao1 = sqlSession1.getMapper(UserDao.class);
User user1 = userDao1.findById(41);
System.out.println(user1);
//关闭一级缓存
sqlSession1.close();
//第二次查询
SqlSession sqlSession2 = sqlSessionFactory.openSession();
UserDao userDao2 = sqlSession2.getMapper(UserDao.class);
User user2 = userDao2.findById(41);
System.out.println(user2);
sqlSession1.close();
System.out.println(user1 == user2);
}
}（1）未开启二级缓存时
（2）开启二级缓存时
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持创新互联。
