一级缓存
获得结果时存入
SqlSession级别的。
默认开启。
二级缓存
会话关闭时存入
应用级别的。
需要手动开启配置。
同一个Session：
@Testpublic void f1() throws IOException {InputStream is = Resources.getResourceAsStream("mybatis.xml");SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);SqlSession s1 = factory.openSession();StudentMapper m1 = s1.getMapper(StudentMapper.class);System.out.println(m1.findById(1));System.out.println(m1.findById(1));s1.close();}
测试结果：
不同的Session：
@Testpublic void f1() throws IOException {InputStream is = Resources.getResourceAsStream("mybatis.xml");SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);SqlSession s1 = factory.openSession();StudentMapper m1 = s1.getMapper(StudentMapper.class);System.out.println(m1.findById(1));s1.close();SqlSession s2 = factory.openSession();StudentMapper m2 = s2.getMapper(StudentMapper.class);System.out.println(m2.findById(1));s2.close();}
测试结果：
开启二级 全局配置Mapper配置实体类实现Serializable全局配置
Mapper配置
几个属性：
eviction：回收策略
LRU（默认）
FIFO
SOFT
WEAK
flushInterval：自动清空间隔秒，默认不清空
readOnly：是否会变动
size：缓存数量
实体类实现
@Data@ToString@NoArgsConstructor@AllArgsConstructorpublic class Student implements Serializable {private Integer id;private String name;private Integer age;}
测试代码：
@Testpublic void f1() throws IOException {InputStream is = Resources.getResourceAsStream("mybatis.xml");SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);SqlSession s1 = factory.openSession();StudentMapper m1 = s1.getMapper(StudentMapper.class);System.out.println(m1.findById(1));s1.close();SqlSession s2 = factory.openSession();StudentMapper m2 = s2.getMapper(StudentMapper.class);System.out.println(m2.findById(1));s2.close();}
测试结果：