Mybatis分页插件使用方法详解

<dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper</artifactId> <version>最新版本</version></dependency>

<!-- plugins在配置文件中的位置必须符合要求，否则会报错，顺序如下: properties?, settings?, typeAliases?, typeHandlers?, objectFactory?,objectWrapperFactory?, plugins?, environments?, databaseIdProvider?, mappers?--><plugins>  <plugin interceptor="com.github.pagehelper.PageHelper">   <property name="dialect" value="mysql"/>   <!-- 该参数默认为false -->   <!-- 设置为true时，会将RowBounds第一个参数offset当成pageNum页码使用 -->   <!-- 和startPage中的pageNum效果一样-->   <property name="offsetAsPageNum" value="true"/>   <!-- 该参数默认为false -->   <!-- 设置为true时，使用RowBounds分页会进行count查询 -->   <property name="rowBoundsWithCount" value="true"/>   <!-- 设置为true时，如果pageSize=0或者RowBounds.limit = 0就会查询出全部的结果 -->   <!-- （相当于没有执行分页查询，但是返回结果仍然是Page类型）-->   <property name="pageSizeZero" value="true"/>   <!-- 3.3.0版本可用 - 分页参数合理化，默认false禁用 -->   <!-- 启用合理化时，如果pageNum<1会查询第一页，如果pageNum>pages会查询最后一页 -->   <!-- 禁用合理化时，如果pageNum<1或pageNum>pages会返回空数据 -->   <property name="reasonable" value="false"/>   <!-- 3.5.0版本可用 - 为了支持startPage(Object params)方法 -->   <!-- 增加了一个`params`参数来配置参数映射，用于从Map或ServletRequest中取值 -->   <!-- 可以配置pageNum,pageSize,count,pageSizeZero,reasonable,不配置映射的用默认值 -->   <!-- 不理解该含义的前提下，不要随便复制该配置 -->   <property name="params" value="pageNum=start;pageSize=limit;"/>  </plugin></plugins>

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <!-- 注意其他配置 --> <property name="plugins"> <array>  <bean class="com.github.pagehelper.PageInterceptor">  <property name="properties">   <!--使用下面的方式配置参数，一行配置一个 -->   <value>   params=value1   </value>  </property>  </bean> </array> </property></bean>

public class BaseRequest implements Serializable { private static final long serialVersionUID = 1193444819529643410L; private Integer pageNum;//页数 private Integer pageSize;//每页行数 private Boolean count;//是否查询总条数 public Integer getPageNum() {  return pageNum; } public void setPageNum(Integer pageNum) {  this.pageNum = pageNum; } public Integer getPageSize() {  return pageSize; } public void setPageSize(Integer pageSize) {  this.pageSize = pageSize; } public Boolean getCount() {  return count; } public void setCount(Boolean count) {  this.count = count; } @Override public String toString() {  return "BaseRequest{" +    "pageNum=" + pageNum +    ", pageSize=" + pageSize +    '}'; }}

public interface PageService { default void setDefaultPageInfo(BaseRequest baseRequest) {  if (null != baseRequest) {   baseRequest.setPageNum(null == baseRequest.getPageNum() ? Constants.PAGE_NUM : baseRequest.getPageNum());   baseRequest     .setPageSize(null == baseRequest.getPageSize() ? Constants.PAGE_SIZE : baseRequest.getPageSize());   baseRequest.setCount(null == baseRequest.getCount() ? Boolean.TRUE : baseRequest.getCount());  } else {   baseRequest = new BaseRequest();   baseRequest.setPageNum(Constants.PAGE_NUM);   baseRequest.setPageSize(Constants.PAGE_SIZE);   baseRequest.setCount(Boolean.TRUE);  }  PageHelper.startPage(baseRequest.getPageNum(), baseRequest.getPageSize(),baseRequest.getCount()); }}

public class PageUtils { public static void copyProperties(PageInfo<?> source, PageInfo<?> des) {  des.setEndRow(source.getEndRow());  des.setFirstPage(source.getFirstPage());  des.setHasNextPage(source.isHasNextPage());  des.setHasPreviousPage(source.isHasPreviousPage());  des.setIsFirstPage(source.isIsFirstPage());  des.setIsLastPage(source.isIsLastPage());  des.setNavigatepageNums(source.getNavigatepageNums());  des.setNavigatePages(source.getNavigatePages());  des.setNextPage(source.getNextPage());  des.setOrderBy(source.getOrderBy());  des.setPageNum(source.getPageNum());  des.setPages(source.getPages());  des.setPageSize(source.getPageSize());  des.setPrePage(source.getPrePage());  des.setSize(source.getSize());  des.setStartRow(source.getStartRow());  des.setTotal(source.getTotal()); }}

import com.github.pagehelper.PageInfo;import com.javxuan.common.util.PageUtils;import com.javxuan.order.entity.Order;import com.javxuan.order.response.OrderDto;import com.javxuan.order.service.PageService;import org.springframework.beans.BeanUtils;import org.springframework.beans.factory.annotation.Autowired;import java.util.ArrayList;public class OrderServcieImpl implements IOrderServcie, PageService { @Autowired IOrderMapper orderMapper; @GetMapping("/order") public PageInfo<OrderDto> list(OrderRequest orderRequest){  //设置默认分页信息 PageService的方法  setDefaultPageInfo(orderRequest);  //查出order列表  List<Order> orderList = orderMapper.selectList();  //将entity的列表分页  PageInfo<Order> orderPageInfo = new PageInfo<>(orderList);  //连续显示5页与上面的二选一  //PageInfo<Order> orderPageInfo = new PageInfo<>(orderList，5);  //定义一个数据传输对象dtoList  List<OrderDto> dtoList = new ArrayList<>();  if(null==orderList || orderList.size<=0){   return null;  }  //给dtoList 加值  for(Order order:orderList){   OrderDto dto = new OrderDto();   //将entity 的属性值 复制给dto上   BeanUtils.copyProperties(order, dto);   dtoList.add(dto);  }  //给dto 分页  PageInfo<OrderDto> dtoPageInfo = new PageInfo<>(dtoList);  //连续显示5页 与上面的二选一  //PageInfo<Order> orderPageInfo = new PageInfo<>(orderList，5);  //将entity的分页信息复制给dtoPageInfo上  PageUtils.copyProperties(orderPageInfo, dtoPageInfo);  return dtoPageInfo; }}