Java使用stream进行分组汇总失效问题

背景

在当前项目的开发任务中需要定制财务报表导出功能，格式比较特殊使用了VM。在汇总数据的过程中使用了stream.collect 进行分组汇总。在测试的过程中发现分组失败，最终原因是对象的对比方式问题，collect是根据对象对比的所以需要重写equals。

问题代码

   private List<SettlementSheet> sumStkPosition(List<SettlementSheet> dataList){
        List<SettlementSheet> resList = new ArrayList<>();
        Map<KeyGroup, List<SettlementSheet>> groupedData = dataList.stream()
                .collect(Collectors.groupingBy(obj -> new KeyGroup(
                        obj.getSEATID_(),
                        obj.getPZ_(),
                        obj.getHOLDERACC_(),
                        obj.getSTKCODE_(),
                        obj.getHEDGINGFLAG_())));
        for (Map.Entry<KeyGroup, List<SettlementSheet>> entry : groupedData.entrySet()) {
            KeyGroup key = entry.getKey();
            List<SettlementSheet> group = entry.getValue();

            double sumBstkamt = group.stream()
                    .mapToDouble(obj -> Double.parseDouble(obj.getBSTKAMT_().toString()))
                    .sum();
            double sumBcap = group.stream()
                    .mapToDouble(obj -> Double.parseDouble(obj.getBSTKAMT_().toString()) *
                            Double.parseDouble(obj.getBCJJJ_().toString()))
                    .sum();
            double avgBcjjj = sumBstkamt == 0 ? 0 : sumBcap / sumBstkamt;
            double sumSstkamt = group.stream()
                    .mapToDouble(obj -> Double.parseDouble(obj.getSSTKAMT_().toString()))
                    .sum();
            double sumScap = group.stream()
                    .mapToDouble(obj -> Double.parseDouble(obj.getSSTKAMT_().toString()) *
                            Double.parseDouble(obj.getSCJJJ_().toString()))
                    .sum();
            double avgScjjj = sumSstkamt == 0 ? 0 : sumScap / sumSstkamt;
            double dzrjs = group.stream()
                    .mapToDouble(obj -> Double.parseDouble(obj.getZRJS_()==null?"0":obj.getZRJS_().toString()))
                    .max()
                    .orElse(0.0);
            double djrjs = group.stream()
                    .mapToDouble(obj -> Double.parseDouble(obj.getJRJS_()==null?"0":obj.getJRJS_().toString()))
                    .max()
                    .orElse(0.0);
            double ddprofit = group.stream()
                    .mapToDouble(obj -> Double.parseDouble(obj.getDPROFIT_().toString()))
                    .sum();
            double dmargin = group.stream()
                    .mapToDouble(obj -> Double.parseDouble(obj.getMARGIN_().toString()))
                    .sum();
            double dstkvalueOptd = group.stream()
                    .mapToDouble(obj -> Double.parseDouble(obj.getSTKVALUEOPTD_().toString()))
                    .sum();
            double dstkvalueOptk = group.stream()
                    .mapToDouble(obj -> Double.parseDouble(obj.getSTKVALUEOPTK_().toString()))
                    .sum();
            SettlementSheet rowData = new SettlementSheet();
            rowData.setSEATID_(key.getSEATID_());
            rowData.setPZ_(key.getPREFIX_());
            rowData.setHOLDERACC_(key.getHOLDERACC_());
            rowData.setSTKCODE_(key.getSTKCODE_());
            rowData.setHEDGINGFLAG_(key.getHEDGINGFLAG_());
            rowData.setBSTKAMT_(BigDecimal.valueOf(sumBstkamt));
            rowData.setBCJJJ_(BigDecimal.valueOf(avgBcjjj).setScale(2, RoundingMode.HALF_UP));
            rowData.setSSTKAMT_(BigDecimal.valueOf(sumSstkamt));
            rowData.setSCJJJ_(BigDecimal.valueOf(avgScjjj).setScale(2, RoundingMode.HALF_UP));
            rowData.setZRJS_(BigDecimal.valueOf(dzrjs));
            rowData.setJRJS_(BigDecimal.valueOf(djrjs));
            rowData.setDPROFIT_(BigDecimal.valueOf(ddprofit));
            rowData.setMARGIN_(BigDecimal.valueOf(dmargin).setScale(2, RoundingMode.HALF_UP));
            rowData.setSTKVALUEOPTD_(BigDecimal.valueOf(dstkvalueOptd));
            rowData.setSTKVALUEOPTK_(BigDecimal.valueOf(dstkvalueOptk));
            resList.add(rowData);
        }
        return resList;
    }

    private class KeyGroup{
        private String SEATID_;

        public KeyGroup(String SEATID_, String PREFIX_, String HOLDERACC_, String STKCODE_, String HEDGINGFLAG_) {
            this.SEATID_ = SEATID_;
            this.PREFIX_ = PREFIX_;
            this.HOLDERACC_ = HOLDERACC_;
            this.STKCODE_ = STKCODE_;
            this.HEDGINGFLAG_ = HEDGINGFLAG_;
        }

        private String PREFIX_;
        private String HOLDERACC_;
        private String STKCODE_;
        private String HEDGINGFLAG_;

        public String getSEATID_() {
            return SEATID_;
        }

        public void setSEATID_(String SEATID_) {
            this.SEATID_ = SEATID_;
        }

        public String getPREFIX_() {
            return PREFIX_;
        }

        public void setPREFIX_(String PREFIX_) {
            this.PREFIX_ = PREFIX_;
        }

        public String getHOLDERACC_() {
            return HOLDERACC_;
        }

        public void setHOLDERACC_(String HOLDERACC_) {
            this.HOLDERACC_ = HOLDERACC_;
        }

        public String getSTKCODE_() {
            return STKCODE_;
        }

        public void setSTKCODE_(String STKCODE_) {
            this.STKCODE_ = STKCODE_;
        }

        public String getHEDGINGFLAG_() {
            return HEDGINGFLAG_;
        }

        public void setHEDGINGFLAG_(String HEDGINGFLAG_) {
            this.HEDGINGFLAG_ = HEDGINGFLAG_;
        }

    }

解决方法

重写equals方法

        @Override
        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj == null || getClass() != obj.getClass()) {
                return false;
            }
            KeyGroup mkPriceKey = (KeyGroup) obj;
            return Objects.equals(this.SEATID_, mkPriceKey.SEATID_) &&
                    Objects.equals(this.PREFIX_, mkPriceKey.PREFIX_) &&
                    Objects.equals(this.HOLDERACC_, mkPriceKey.HOLDERACC_) &&
                    Objects.equals(this.STKCODE_, mkPriceKey.STKCODE_) &&
                    Objects.equals(this.HEDGINGFLAG_, mkPriceKey.HEDGINGFLAG_);
        }

修正后代码

    private class KeyGroup{
        private String SEATID_;

        public KeyGroup(String SEATID_, String PREFIX_, String HOLDERACC_, String STKCODE_, String HEDGINGFLAG_) {
            this.SEATID_ = SEATID_;
            this.PREFIX_ = PREFIX_;
            this.HOLDERACC_ = HOLDERACC_;
            this.STKCODE_ = STKCODE_;
            this.HEDGINGFLAG_ = HEDGINGFLAG_;
        }

        private String PREFIX_;
        private String HOLDERACC_;
        private String STKCODE_;
        private String HEDGINGFLAG_;

        public String getSEATID_() {
            return SEATID_;
        }

        public void setSEATID_(String SEATID_) {
            this.SEATID_ = SEATID_;
        }

        public String getPREFIX_() {
            return PREFIX_;
        }

        public void setPREFIX_(String PREFIX_) {
            this.PREFIX_ = PREFIX_;
        }

        public String getHOLDERACC_() {
            return HOLDERACC_;
        }

        public void setHOLDERACC_(String HOLDERACC_) {
            this.HOLDERACC_ = HOLDERACC_;
        }

        public String getSTKCODE_() {
            return STKCODE_;
        }

        public void setSTKCODE_(String STKCODE_) {
            this.STKCODE_ = STKCODE_;
        }

        public String getHEDGINGFLAG_() {
            return HEDGINGFLAG_;
        }

        public void setHEDGINGFLAG_(String HEDGINGFLAG_) {
            this.HEDGINGFLAG_ = HEDGINGFLAG_;
        }

        @Override
        public int hashCode() {
            return Objects.hash(SEATID_, PREFIX_, HOLDERACC_, STKCODE_, HEDGINGFLAG_);
        }

        @Override
        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj == null || getClass() != obj.getClass()) {
                return false;
            }
            KeyGroup mkPriceKey = (KeyGroup) obj;
            return Objects.equals(this.SEATID_, mkPriceKey.SEATID_) &&
                    Objects.equals(this.PREFIX_, mkPriceKey.PREFIX_) &&
                    Objects.equals(this.HOLDERACC_, mkPriceKey.HOLDERACC_) &&
                    Objects.equals(this.STKCODE_, mkPriceKey.STKCODE_) &&
                    Objects.equals(this.HEDGINGFLAG_, mkPriceKey.HEDGINGFLAG_);
        }
    }

总结

应该有更好的实现方式，java使用的不是很熟练。之后有新思路再来更新。