java 批量更新方法

public Boolean batchOperationPublic(List rule, String tableName, List> allData) throws Exception {
        //rule 更新的条件字段
        //tableName 更新的表名
        //allData结果集
        //取结果集的第一条数据的字段
        Set allColum = allData.get(0).keySet();
        //取条件字段和第一条数据的字段的差集
        List updateColumns = (List) CollectionUtils.subtract(allColum, rule);
        //拼接sql
        String q = "";
        for (String uColum : updateColumns) {
            q = q + "`" + uColum + "` =case ";
            for (Map data : allData) {
                q = q + " when ";
                Integer i = 0;
                for (String item : rule) {
                    if (i == 0) {
                        q = q + item + "= '" + data.get(item) + "' ";
                    } else {
                        q = q + " and " + item + "= '" + data.get(item) + "' ";
                    }
                    i++;
                }
                if (data.get(uColum) != null) {
                    q = q + " then '" + data.get(uColum) + "' ";
                } else {
                    q = q + " then null ";
                }
            }
            q = q + " else `" + uColum + "` end, ";
        }
        q = q.substring(0, q.length() - 2);
        try {
            batchOperationDao.updateBatchByColumns(tableName, q);
            return true;
        } catch (ParseException e) {
            return false;
        }