Mybatis_分页(pageHelper插件实现)

1. 在pom.xml中添加pageHelper依赖

<!-- https://mvnrepository.com/artifact/com.github.pagehelper/pagehelper -->
<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper</artifactId>
    <version>5.1.10</version>
</dependency>

2. 在mybatis配置文件中添加插件依赖

<plugin interceptor="com.github.pagehelper.PageInterceptor">
<!-- 配置数据库的类型 -->
	<property name="helperDialect" value="mysql"/>
	<property name="reasonable" value="true"/>
</plugin>

3. DAO层Mapper写法和无分页写法相同，在Service层调用插件

public class UserService {
	/**
	 * 
	 * @param pageNum
	 * @param map
	 * @return
	 */
	public PageInfo<User> selectPage(int pageNum, Map<String, Object> map) {

		SqlSession sqlSession = SqlSessionUtil.openSession();
		try {
			UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
			//开启分页功能
			PageHelper.startPage(pageNum, 5);
			List<User> users = userMapper.select(map);
			//PageInfo对象获得非常全面的分页信息
			PageInfo<User> page = new PageInfo<User>(users);
			return page;
		} finally {
			SqlSessionUtil.close(sqlSession);
		}
	}
}

Debug模式下查看到PageInfo中的属性，常用的pageNum当前页，pages总页数，list分页查询的数据等…