LambdaQueryWrapper 设置自定义排序

MybatisPlus版本

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.2</version>
</dependency>
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-extension</artifactId>
    <version>3.4.2</version>
</dependency>

定义MybatisPlus工具类

import com.baomidou.mybatisplus.core.conditions.ISqlSegment;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.metadata.OrderItem;
import com.xnt.product.common.core.core.domain.OrderBy;
import com.xnt.product.common.core.exception.CustomException;

import java.util.List;

import static com.baomidou.mybatisplus.core.enums.SqlKeyword.*;

/**
 * @author wxm
 */
public class MybatisPlusUtil {

    /**
     * @param queryWrapper {@link LambdaQueryWrapper}
     * @param column       排序字段
     * @param asc          是否升序
     * @param <T>          泛型
     */
    public static <T> void setOrderOne(LambdaQueryWrapper<T> queryWrapper, String column, boolean asc) {
        try {
            ISqlSegment[] sqlSegments = {ORDER_BY, () -> column, asc ? ASC : DESC};
            queryWrapper.getExpression().add(sqlSegments);
        } catch (Exception e) {
            e.printStackTrace();
            throw new CustomException("设置排序出错：" + e.getMessage());
        }
    }

    /**
     * @param queryWrapper {@link LambdaQueryWrapper}
     * @param order        {@link OrderBy} 排序
     * @param <T>          泛型
     */
    public static <T> void setOrder(LambdaQueryWrapper<T> queryWrapper, OrderBy order) {
        setOrderOne(queryWrapper, order.getColumn(), order.isAsc());
    }

    /**
     * @param queryWrapper {@link LambdaQueryWrapper}
     * @param list         {@link OrderBy} 排序
     * @param <T>          泛型
     */
    public static <T> void setOrder(LambdaQueryWrapper<T> queryWrapper, List<OrderBy> list) {
        for (OrderBy order : list) {
            setOrder(queryWrapper, order);
        }
    }

    /**
     * @param queryWrapper {@link LambdaQueryWrapper}
     * @param orderItem    {@link OrderItem} 排序
     * @param <T>          泛型
     */
    public static <T> void setOrderItem(LambdaQueryWrapper<T> queryWrapper, OrderItem orderItem) {
        setOrderOne(queryWrapper, orderItem.getColumn(), orderItem.isAsc());
    }

    /**
     * @param queryWrapper {@link LambdaQueryWrapper}
     * @param list         {@link OrderItem} 排序
     * @param <T>          泛型
     */
    public static <T> void setOrderItem(LambdaQueryWrapper<T> queryWrapper, List<OrderItem> list) {
        for (OrderItem order : list) {
            setOrderItem(queryWrapper, order);
        }
    }
}

定义OrderBy实体类

@Data
public class OrderBy {

    /**
     * 字段名称
     */
    @NotEmpty
    private String column;

    /**
     * 排序类型 升序：asc 降序：desc
     * 默认升序
     */
    private boolean asc = true;

    /**
     * 是否进行驼峰转下划线
     */
    private boolean toUnder = false;

    public String getColumn() {
        return isToUnder() ? StrUtil.toUnderlineCase(column) : column;
    }

    public String getColumn(boolean toUnder) {
        return toUnder ? StrUtil.toUnderlineCase(column) : column;
    }

    /**
     * 获取 OrderItem
     *
     * @return
     */
    public OrderItem getOrderItem() {
        return getOrderItem(isAsc(), isToUnder());
    }

    /**
     * 获取 OrderItem
     *
     * @param isAsc 是否升序
     * @return
     */
    public OrderItem getOrderItem(boolean isAsc) {
        return getOrderItem(isAsc, isToUnder());
    }

    /**
     * 获取 OrderItem
     *
     * @param isToUnder 是否进行驼峰转下划线
     * @return
     */
    public OrderItem getOrderItemToUnder(boolean isToUnder) {
        return getOrderItem(isAsc(), isToUnder);
    }

    /**
     * 获取 OrderItem
     *
     * @param sort      排序方式  升序：asc 降序：desc
     * @param isToUnder 是否进行驼峰转下划线
     * @return
     */
    public OrderItem getOrderItem(String sort, boolean isToUnder) {
        return getOrderItem(isAsc(), isToUnder);
    }

    /**
     * 获取 OrderItem
     *
     * @param isAsc     是否升序
     * @param isToUnder 是否进行驼峰转下划线
     * @return
     */
    public OrderItem getOrderItem(boolean isAsc, boolean isToUnder) {
        String col = isToUnder ? StrUtil.toUnderlineCase(column) : column;
        return OrderItemUtils.getOrder(col, isAsc);
    }

    /**
     * 获取sql
     * @return
     */
    public String getSql(){
        return (isToUnder() ? StrUtil.toUnderlineCase(column) : column) + (this.isAsc()? " asc":" desc");
    }
 }

使用自定义排序

1、获取前段参数

public List<OrderBy> getOrderBys() {
        String order = ServletUtils.getParameter(PageConstants.ORDER);
        if (ObjectUtil.isEmpty(order)) {
            return null;
        }
        List<OrderBy> orderByList = new ArrayList<>();
        if (JsonUtil.isTypeJSONArray(order)) {
            orderByList.addAll(JsonUtil.toList(order, OrderBy.class));
        } else {
            orderByList.add(JsonUtil.parse(order, OrderBy.class));
        }
        return orderByList;
    }

2、调用工具类

public List<SysOperLog> getList(SysOperLog operLog) {
        LambdaQueryWrapper<SysOperLog> lambda = getLambda();
   
        List<OrderItem> list = getOrderItems();
        if (ObjectUtils.isNotEmpty(list)) {
            MybatisPlusUtil.setOrderItem(lambda, list);
        } else {
            lambda.orderByDesc(SysOperLog::getOperTime);
        }
        return super.list(lambda);
    }