content: package org.jeecg.modules.system.rule;
  
  import com.alibaba.fastjson.JSONObject;
  import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
  import org.jeecg.common.handler.IFillRuleHandler;
  import org.jeecg.common.util.SpringContextUtils;
  import org.jeecg.common.util.YouBianCodeUtil;
  import org.jeecg.common.util.oConvertUtils;
  import org.jeecg.modules.system.entity.SysCategory;
  import org.jeecg.modules.system.mapper.SysCategoryMapper;
  
  import java.util.List;
  
  /**
   * @Author scott
   * @Date 2019/12/9 11:32
   * @Description: 分类字典编码生成规则
   */
  public class CategoryCodeRule implements IFillRuleHandler {
  
      public static final String ROOT_PID_VALUE = "0";
  
      @Override
      public Object execute(JSONObject params, JSONObject formData) {
  
          String categoryPid = ROOT_PID_VALUE;
          String categoryCode = null;
  
          if (formData != null && formData.size() > 0) {
              Object obj = formData.get("pid");
              if (oConvertUtils.isNotEmpty(obj)) categoryPid = obj.toString();
          } else {
              if (params != null) {
                  Object obj = params.get("pid");
                  if (oConvertUtils.isNotEmpty(obj)) categoryPid = obj.toString();
              }
          }
  
          /*
           * 分成三种情况
           * 1.数据库无数据 调用YouBianCodeUtil.getNextYouBianCode(null);
           * 2.添加子节点，无兄弟元素 YouBianCodeUtil.getSubYouBianCode(parentCode,null);
           * 3.添加子节点有兄弟元素 YouBianCodeUtil.getNextYouBianCode(lastCode);
           * */
          //找同类 确定上一个最大的code值
          LambdaQueryWrapper<SysCategory> query = new LambdaQueryWrapper<SysCategory>().eq(SysCategory::getPid, categoryPid).isNotNull(SysCategory::getCode).orderByDesc(SysCategory::getCode);
          SysCategoryMapper baseMapper = (SysCategoryMapper) SpringContextUtils.getBean("sysCategoryMapper");
          List<SysCategory> list = baseMapper.selectList(query);
          if (list == null || list.size() == 0) {
              if (ROOT_PID_VALUE.equals(categoryPid)) {
                  //情况1
                  categoryCode = YouBianCodeUtil.getNextYouBianCode(null);
              } else {
                  //情况2
                  SysCategory parent = (SysCategory) baseMapper.selectById(categoryPid);
                  categoryCode = YouBianCodeUtil.getSubYouBianCode(parent.getCode(), null);
              }
          } else {
              //情况3
              categoryCode = YouBianCodeUtil.getNextYouBianCode(list.get(0).getCode());
          }
          return categoryCode;
      }
  }
  