【MyBatis】通过分页助手完成分页查询

1、简介

        分页助手可以是的分页查询变得十分方便

2、实现

        2.1 导入坐标

        <dependency>
            <groupId>com.github.pagehelpergroupId>
            <artifactId>pagehelperartifactId>
            <version>5.3.2version>
        dependency>
 
        <dependency>
            <groupId>com.github.jsqlparsergroupId>
            <artifactId>jsqlparserartifactId>
            <version>4.5version>
        dependency>

        2.2 在MyBatis核心配置文件中配置plugins标签

    <plugins>
        <plugin interceptor="com.github.pagehelper.PageInterceptor">plugin>
    plugins>

        2.3 测试

    @Test
    public void test01() throws IOException {
        InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapConfig.xml");
        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
        SqlSession sqlSession = sessionFactory.openSession();
 
        HobbyMapper mapper = sqlSession.getMapper(HobbyMapper.class);
 
        PageHelper.startPage(1,3);
        List hobbyList = mapper.findAll();
        for (Hobby hobby : hobbyList) {
            System.out.println(hobby);
        }
        sqlSession.close();
 
    }

        注意：PageHelper.startPage(1,3)需要在调用SQL语句之前

通过PageInfo的对象也可以获取一些分页相关的参数

        PageInfo pageInfo = new PageInfo(hobbyList);
        System.out.println(pageInfo.getPageNum());
        System.out.println(pageInfo.getPrePage());
        System.out.println(pageInfo.getSize());
        System.out.println(pageInfo.getStartRow());