不积跬步无以至千里（代码优化篇）

进入用友后，第一次的代码

优化前：

优化后：

优化前：

优化后：

    /**
     * 复制盘点计划
     * @param planid
     * @return
     * @author xinqq
     * @create 2019-12-06 17:00
     */
    public Plan copyPlan(String planid){
        if(StringUtils.isBlank(planid))
            throwBusinessException(I18nEnum.COMMON4);
        Plan oldPlan = queryService.queryPlanById(planid);
        Plan copyPlan = new Plan();
        BeanUtils.copyProperties(oldPlan,copyPlan,"id","name","version","state","creatorname","archivetime");
        copyPlan.setName(oldPlan.getName()+ Toolkit.dateToStr(new Date(),"yyyyMMddhhmmss"));
        copyPlan.setState(OtrConstant.PlanType.NEW.getCode());
        copyPlan.setVersion(OtrConstant.GLOBAL_SCHEME_VERSION);
        copyPlan.setCreatorname(StaffHelper.queryStaffNameByUserId(InvocationInfoProxy.getUserid()));
        genericService.insert(copyPlan);
        String copyPlanId = copyPlan.getId();
        List<PlanGroup> oldPlanGroups = groupService.queryPlanGroupByPlanId(planid);
        List<PlanObject> objs = new ArrayList<>();
        oldPlanGroups.forEach(group->{
            PlanGroup newGroup = new PlanGroup();
            BeanUtils.copyProperties(group,newGroup,"id","planid");
            newGroup.setPlanid(copyPlanId);
            genericService.insert(newGroup);
            Condition cond = new Condition();
            cond.addExpression("planid",planid);
            cond.addExpression("plangroupid",group.getId());
            group.setPlanObjects(objService.queryPlanObjectListByCond(cond,null));
            group.getPlanObjects().forEach(obj->{
                PlanObject newObj = new PlanObject();
                BeanUtils.copyProperties(obj,newObj,"id","planid","plangroupid","userid");
                newObj.setPlangroupid(newGroup.getId());
                newObj.setPlanid(copyPlanId);
                newObj.setUserid(InvocationInfoProxy.getUserid());
                objs.add(newObj);
            });
        });
        genericService.insertBatch(objs);
        copyPlan.setPlanobjects(objs);
        return copyPlan;
    }

第二次代码

优化前：

优化后：

优化前：

问题：假如有100（大量）的entry，则forEach中就需要与数据库交互200次，严重影响性能。
改为：先批量查出来，再一一设置对应

优化后：

 @Override
    public List<Entry> queryEntryListByCond(Condition cond, Sorter sorter, Boolean wrapClassifyNameAndEvaluateGrades) {
        List<Entry> entries = genericService.find(Entry.class, cond, sorter);
        if(CollectionUtils.isEmpty(entries) || !wrapClassifyNameAndEvaluateGrades){
            return entries;
        }
        //设置分类名称
        List<String> classifyIds = entries.stream().map(item -> item.getClassifyid()).collect(Collectors.toList());
        Map<String, EntryClassify> mapByClassifyId = entryClassifyService.queryClassifyMapByIds(classifyIds);
        entries.forEach( item ->{
            if(mapByClassifyId.get(item.getClassifyid()) != null){
                item.setClassifyname(mapByClassifyId.get(item.getClassifyid()).getName());
            }
        });
        //设置评价等级
        List<String> entryIds = entries.stream().map(item -> item.getId()).collect(Collectors.toList());
        Map<String, List<EvaluateGrade>> mapByEntryId = queryEvaluateGradeByEntryId(entryIds);
        entries.forEach( item -> {
            if(mapByEntryId.get(item.getId()) != null){
                item.setEvaluateGrades(mapByEntryId.get(item.getId()));
            }
        });
        return entries;
    }

    //通过entryids查询EvaluateGrades
    private Map<String, List<EvaluateGrade>> queryEvaluateGradeByEntryId(List<String> entryids){
        Condition cond = ConditionUtils.buildInExpression(null, entryids, "entryid");
        //评价等级暂时按照创建时间倒叙排列
        Sorter sorter = ConditionUtils.buildSorter4CreationtimeDesc();
        return evaluateGradeService.queryListByCond(cond, sorter)
                .stream().collect(Collectors.groupingBy(EvaluateGrade::getEntryid));
    }

而且优化后，queryEntryListByCond()yCond()方法完全可以代替queryEntryById()方法
像下面这样：
优化前：

优化后：

 @ApiOperation(value = "查看词条详情")
    @GetMapping("/queryDetail/{id}")
    public MessageResult queryEntryDetail(@PathVariable("id") String id){
        Condition cond = new Condition();
        cond.addExpression("id",id);
        return Toolkit.getResponseBody(settingService.queryEntryListByCond(cond, null, true),I18nEnum.QUERY);
    }

    @ApiOperation(value = "浏览词条")
    @GetMapping("/queryEntrys")
    public MessageResult queryEntrys(@RequestParam String entryClassifyId){
        Condition cond = new Condition();
        cond.addExpression("classifyid",entryClassifyId);
        Sorter sorter = ConditionUtils.buildSorter4CreationtimeDesc();
        return Toolkit.getResponseBody(settingService.queryEntryListByCond(cond, sorter, false),I18nEnum.QUERY);
    }

来源：CSDN

作者：xq_zzu

链接：https://blog.csdn.net/xq_zzu/article/details/103622450