Mybatis之分页插件-阿里云开发者社区

<!-- https://mvnrepository.com/artifact/com.github.pagehelper/pagehelper --><dependency><groupId>com.github.pagehelper</groupId><artifactId>pagehelper</artifactId><version>5.2.0</version></dependency>

2、配置分页插件

在MyBatis的核心配置文件（mybatis-config.xml）中配置插件

<plugins><!--设置分页插件--><plugininterceptor="com.github.pagehelper.PageInterceptor"></plugin></plugins>

二、分页插件的使用

1、开启分页功能

在查询功能之前使用PageHelper.startPage(int pageNum, int pageSize)开启分页功能

pageNum：当前页的页码
pageSize：每页显示的条数

@TestpublicvoidtestPageHelper() throwsIOException {
InputStreamis=Resources.getResourceAsStream("mybatis-config.xml");
SqlSessionFactoryBuildersqlSessionFactoryBuilder=newSqlSessionFactoryBuilder();
SqlSessionFactorysqlSessionFactory=sqlSessionFactoryBuilder.build(is);
SqlSessionsqlSession=sqlSessionFactory.openSession(true);
EmpMappermapper=sqlSession.getMapper(EmpMapper.class);
//访问第一页，每页四条数据PageHelper.startPage(1,4);
List<Emp>emps=mapper.selectByExample(null);
emps.forEach(System.out::println);
}

2、分页相关数据

方法一：直接输出

@TestpublicvoidtestPageHelper() throwsIOException {
InputStreamis=Resources.getResourceAsStream("mybatis-config.xml");
SqlSessionFactoryBuildersqlSessionFactoryBuilder=newSqlSessionFactoryBuilder();
SqlSessionFactorysqlSessionFactory=sqlSessionFactoryBuilder.build(is);
SqlSessionsqlSession=sqlSessionFactory.openSession(true);
EmpMappermapper=sqlSession.getMapper(EmpMapper.class);
//访问第一页，每页四条数据Page<Object>page=PageHelper.startPage(1, 4);
List<Emp>emps=mapper.selectByExample(null);
//在查询到List集合后，打印分页数据System.out.println(page);
}

分页相关数据：

Page{count=true, pageNum=1, pageSize=4, startRow=0, endRow=4, total=8, pages=2, reasonable=false, pageSizeZero=false}[Emp{eid=1, empName='admin', age=22, sex='男', email='456@qq.com', did=3}, Emp{eid=2, empName='admin2', age=22, sex='男', email='456@qq.com', did=3}, Emp{eid=3, empName='王五', age=12, sex='女', email='123@qq.com', did=3}, Emp{eid=4, empName='赵六', age=32, sex='男', email='123@qq.com', did=1}]

方法二使用PageInfo

在查询获取list集合之后，使用PageInfo<T> pageInfo = new PageInfo<>(List<T> list, intnavigatePages)获取分页相关数据

list：分页之后的数据
navigatePages：导航分页的页码数

@TestpublicvoidtestPageHelper() throwsIOException {
InputStreamis=Resources.getResourceAsStream("mybatis-config.xml");
SqlSessionFactoryBuildersqlSessionFactoryBuilder=newSqlSessionFactoryBuilder();
SqlSessionFactorysqlSessionFactory=sqlSessionFactoryBuilder.build(is);
SqlSessionsqlSession=sqlSessionFactory.openSession(true);
EmpMappermapper=sqlSession.getMapper(EmpMapper.class);
PageHelper.startPage(1, 4);
List<Emp>emps=mapper.selectByExample(null);
PageInfo<Emp>page=newPageInfo<>(emps,5);
System.out.println(page);
}

分页相关数据：

PageInfo{
pageNum=1, pageSize=4, size=4, startRow=1, endRow=4, total=8, pages=2, 
list=Page{count=true, pageNum=1, pageSize=4, startRow=0, endRow=4, total=8, pages=2, reasonable=false, pageSizeZero=false}[Emp{eid=1, empName='admin', age=22, sex='男', email='456@qq.com', did=3}, Emp{eid=2, empName='admin2', age=22, sex='男', email='456@qq.com', did=3}, Emp{eid=3, empName='王五', age=12, sex='女', email='123@qq.com', did=3}, Emp{eid=4, empName='赵六', age=32, sex='男', email='123@qq.com', did=1}], 
prePage=0, nextPage=2, isFirstPage=true, isLastPage=false, hasPreviousPage=false, hasNextPage=true, navigatePages=5, navigateFirstPage=1, navigateLastPage=2, navigatepageNums=[1, 2]}