pagehelper分页插件的使用

pagehelper分页插件的使用

第一步:导入需要的maven坐标

<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper</artifactId>
    <version>3.7.5</version>
</dependency>
<dependency>
    <groupId>com.github.jsqlparser</groupId>
    <artifactId>jsqlparser</artifactId>
    <version>0.9.1</version>
</dependency>

第二步:在mybatis配置文件中使用进行配置,实际上相当于告诉mybatis使用了此插件

<!--配置分页助手插件-->
<plugins>
    <plugin interceptor="com.github.pagehelper.PageHelper">
        <property name="dialect" value="oracle"></property><!--方言为oracle,也可以配置为mysql-->
    </plugin>
</plugins>

第三步:使用分页插件pagehelper

@Test
public void fun7() throws IOException {
    InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapConfig.xml");
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
    SqlSession sqlSession = sqlSessionFactory.openSession();
    EmpMapper mapper = sqlSession.getMapper(EmpMapper.class);

    //查询条件之前加上此分页条件
    PageHelper.startPage(1,2);
    List<Emp> empList =  mapper.findAll();

    //获取分页信息
    PageInfo<Emp> pageInfo = new PageInfo<>(empList);
    System.out.println("总条数:"+pageInfo.getTotal());
    System.out.println("总页数:"+pageInfo.getPages());
    System.out.println("当前页数:"+pageInfo.getPageNum());
    System.out.println("每页长度:"+pageInfo.getPageSize());
    System.out.println("是否是第一页:"+pageInfo.isIsFirstPage());
    System.out.println("是否是最后一页:"+pageInfo.isIsLastPage());

    //打印查询内容
    for (Emp emp : empList) {
        System.out.println(emp);
    }
    System.out.println(empList);
}