mybatisplus做SQL拦截添加自定义排序

前言

工作中写的一段代码，备个份，以后兴许能直接用

功能描述：如果前端传入了排序规则，则优先按传入的字段进行排序，SQL原有的排序规则追加到末尾

正文

定义拦截器


import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.collection.CollUtil;
import com.baomidou.mybatisplus.core.toolkit.PluginUtils;
import com.baomidou.mybatisplus.extension.parser.JsqlParserSupport;
import com.baomidou.mybatisplus.extension.plugins.inner.InnerInterceptor;
import lombok.extern.slf4j.Slf4j;
import net.sf.jsqlparser.schema.Column;
import net.sf.jsqlparser.statement.select.OrderByElement;
import net.sf.jsqlparser.statement.select.PlainSelect;
import net.sf.jsqlparser.statement.select.Select;
import org.apache.ibatis.binding.MapperMethod;
import org.apache.ibatis.executor.statement.StatementHandler;
import org.jetbrains.annotations.Nullable;import java.sql.Connection;
import java.util.List;/*** 添加自定义排序规则* 如果前端传入了排序规则，则优先按传入的字段进行排序，SQL原有的排序规则追加到末尾* 这个SQL的处理方式【不是基于】字符串拼接，底层的SQL执行是基于 com.mysql.cj.jdbc.ClientPreparedStatement.execute,*  PreparedStatement 是防SQL注入的，强行做SQL注入会抛语法错误的异常 - syntax exception* @author weiheng* @date 2024-01-23**/
@Slf4j
public class MybatisPageOrderSqlInterceptor extends JsqlParserSupport implements InnerInterceptor {/** 排序方式 - 升序 */private static final String SORT_ASC = "asc";@Overridepublic void beforePrepare(StatementHandler sh, Connection connection, Integer transactionTimeout) {if (log.isDebugEnabled()) {log.info(">>>>> 自定义排序拦截 StatementHandler[{}]", sh);log.info(">>>>> 自定义排序拦截 connection[{}]", connection);log.info(">>>>> 自定义排序拦截 transactionTimeout[{}]", transactionTimeout);}PluginUtils.MPStatementHandler mpSh = PluginUtils.mpStatementHandler(sh);PluginUtils.MPBoundSql mpBs = mpSh.mPBoundSql();// 取分页查询的入参 PageDTOPageDTO pageDto = getPageDTO(mpSh);if (pageDto == null || CollUtil.isEmpty(pageDto.getOrderColumns())) {// 不是自定义分页查询，不做处理return;}mpBs.sql(parserMulti(mpBs.sql(), pageDto));}@Overrideprotected void processSelect(Select select, int index, String sql, Object obj) {PageDTO dto;if (obj instanceof PageDTO) {dto = (PageDTO) obj;} else {// 如果不是分页查询，则不做处理return;}// 1. 解析SQLPlainSelect plainSelect = (PlainSelect) select.getSelectBody();List<OrderByElement> originOrderList = plainSelect.getOrderByElements();List<OrderByElement> clonedOriginOrder = null;if (CollUtil.isNotEmpty(originOrderList)) {// 创建副本，然后删除原有排序规则clonedOriginOrder = BeanUtil.copyToList(originOrderList, OrderByElement.class);originOrderList.clear();}// 2. 向 plainSelect 中添加自定义排序规则addCustomizeSortColumns(dto, plainSelect);// 3. 添加SQL的原始排序规则 - 追加到末尾if (CollUtil.isNotEmpty(clonedOriginOrder)) {plainSelect.addOrderByElements(clonedOriginOrder);}if (log.isDebugEnabled()) {log.info("<<<<< 自定义排序拦截 plainSelect[{}]", plainSelect);}}/*** 添加自定义排序规则** @param dto SQL查询入参* @param plainSelect 明文* @author weiheng**/private void addCustomizeSortColumns(PageDTO dto, PlainSelect plainSelect) {List<OrderColumnDTO> orderColumns = dto.getOrderColumns();for (OrderColumnDTO c : orderColumns) {// 构建新的排序规则OrderByElement orderByElement = new OrderByElement();// 设置排序 - 不传值则默认asc升序orderByElement.setAsc(SORT_ASC.equalsIgnoreCase(c.getSort()));// 设置排序字段orderByElement.setExpression(new Column(c.getOrderColumn()));// 重新封装条件 - 优先按自定义进行排序plainSelect.addOrderByElements(orderByElement);}}/*** 分页查询入参获取* 大概搜了下，没有到3个入参的，如果有，请将 PageDTO 放到第1或第2的位置* @param mpSh 处理对象* @return 分页查询入参* @author weiheng**/@Nullableprivate PageDTO getPageDTO(PluginUtils.MPStatementHandler mpSh) {PageDTO pageDto = null;Object obj = mpSh.parameterHandler().getParameterObject();try {Object param = ((MapperMethod.ParamMap<?>) obj).get("param1");if (param instanceof PageDTO) {pageDto = (PageDTO) param;} else {param = ((MapperMethod.ParamMap<?>) obj).get("param2");if (param instanceof PageDTO) {pageDto = (PageDTO) param;}}} catch (Exception e) {// 没有从SQL中获取到对应的参数（没有param1或param2），不走自定义分页逻辑}return pageDto;}}

添加插件 - 添加自定义的拦截器


import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.BlockAttackInnerInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.OptimisticLockerInnerInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;/*** mybatis配置* @author Heng.Wei* @date 2022-05-11**/
@Configuration
public class MybatisPlusConfig {@Beanpublic MybatisPlusInterceptor paginationInterceptor() {MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();// 乐观锁插件interceptor.addInnerInterceptor(new OptimisticLockerInnerInterceptor());// 分页插件interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));// 添加防止全表更新与删除插件interceptor.addInnerInterceptor(new BlockAttackInnerInterceptor());// 深度分页插件interceptor.addInnerInterceptor(new MybatisHighPageInterceptor());// 添加自定义排序interceptor.addInnerInterceptor(new MybatisPageOrderSqlInterceptor());return interceptor;}
}