結(jié)論

• list查詢改成map查詢

Person有身份證字段：id
List<Person> list

找到list中id=xxx的person

解決：
先將list轉(zhuǎn)為Map<String, Person> key為id,通過map.get(xx)提升性能

• list所有數(shù)據(jù)修改采用多線程

1.parallelStream.forEach()
缺點(diǎn)：main線程可能不會等待結(jié)束

2.Lists.partition(list, 1000);以1000大小分組
每個(gè)組使用線程池執(zhí)行
優(yōu)點(diǎn)：分組執(zhí)行凯亮，每個(gè)線程執(zhí)行各自的私有l(wèi)ist,無鎖的操作代價(jià)，最快

3.使用ConcurrentLinkedQueue 共享list味悄，創(chuàng)建n個(gè)線程同時(shí)處理這個(gè)queue
缺點(diǎn)：多線程操作同一個(gè)queue，有鎖的判斷代價(jià)

3 demo

        log.info("111-1");
        
        //這種有4w條數(shù)據(jù)時(shí)反射啥的巨耗時(shí)
        
/*        List<CompanyRiskWarnVo> warnVos = dataRecords
                .stream()
                .map(dataRecord -> DataRecordTransform.toBean(dataRecord, CompanyRiskWarnVo.class))
                .collect(Collectors.toList());*/

        List<CompanyRiskWarnVo> warnVos = new ArrayList<>(dataRecords.size());

//按照上面3分組 ，每組一個(gè)線程執(zhí)行吝秕，統(tǒng)一匯總結(jié)果
        List<List<DataRecord>> dataRecordParts = Lists.partition(dataRecords, 1000);

        List<Future<List<CompanyRiskWarnVo>>> recordFuture = new ArrayList<>();

        for (List<DataRecord> dataRecordPart : dataRecordParts) {
            Future<List<CompanyRiskWarnVo>> submit = threadPoolExecutor.submit(new Callable<List<CompanyRiskWarnVo>>() {
                @Override
                public List<CompanyRiskWarnVo> call() throws Exception {
                    try {
                        if (CollectionUtils.isNotEmpty(dataRecordPart)) {
                            return dataRecordPart.stream().map(dataRecord -> DataRecordTransform.toBean(dataRecord, CompanyRiskWarnVo.class)).collect(Collectors.toList());
                        }
                        return Collections.emptyList();
                    } catch (Exception e) {
                        return Collections.emptyList();
                    }
                }

            });

            recordFuture.add(submit);
        }

        for (Future<List<CompanyRiskWarnVo>> future : recordFuture) {
            List<CompanyRiskWarnVo> riskWarnVos = null;
            try {
                riskWarnVos = future.get();
            }  catch (Exception e) {
                log.warn("get transfer error, ", e);
                riskWarnVos = Collections.emptyList();
            }
            warnVos.addAll(riskWarnVos);
        }

stream.parallel

• 底層forkjoin多線程
• main線程會等待多線程結(jié)束
• ArrayList相對linkedList更適合stream遍歷,容易隨機(jī)拆分

[INFO  2022-12-07 10:26:53.907][main][:--]com.xiaomi.scf.risk.web.manager.CommonTest.lambda$parallel$2(CommonTest.java:258)[in parallel]
[INFO  2022-12-07 10:26:53.907][ForkJoinPool.commonPool-worker-1][:--]com.xiaomi.scf.risk.web.manager.CommonTest.lambda$parallel$2(CommonTest.java:258)[in parallel]
[INFO  2022-12-07 10:26:53.907][ForkJoinPool.commonPool-worker-2][:--]com.xiaomi.scf.risk.web.manager.CommonTest.lambda$parallel$2(CommonTest.java:258)[in parallel]
[INFO  2022-12-07 10:26:55.911][ForkJoinPool.commonPool-worker-3][:--]com.xiaomi.scf.risk.web.manager.CommonTest.lambda$parallel$2(CommonTest.java:258)[in parallel]
[INFO  2022-12-07 10:26:55.911][ForkJoinPool.commonPool-worker-5][:--]com.xiaomi.scf.risk.web.manager.CommonTest.lambda$parallel$2(CommonTest.java:258)[in parallel]
[INFO  2022-12-07 10:26:55.911][main][:--]com.xiaomi.scf.risk.web.manager.CommonTest.parallel(CommonTest.java:264)[main end]