java Future实现多线程执行

时间:2022-05-23 坚持是一种态度人气:0

场景

网站智能问答场景，需要对多个分类查询，结果聚合展示

由于每种分类都有自己的业务逻辑，有的需要查询数据库中间库，有的需要查询elasticsearch搜索引擎，有的需要调用第三方接口，数据查询要分开进行，没法一次查询搞定

实际上这几个查询不相关，可以同时进行，现在串行，使该场景下，智能问答返回较慢

解决

最简单的逻辑，肯定就是java多线程，将串行改为并行

这样查询返回时间，就取决于最慢的一个查询，返回时间大大缩短

页面返回一般要求三秒内，实际项目上我们要求1秒内返回，多线程解决了这个问题

下面上代码，部分截取

	@Autowired
    private ThreadPoolTaskExecutor taskExecutor;

// 新闻查询
            SolrPageQueryVO newsQueryVO = new SolrPageQueryVO();
            BeanUtil.copyProperties(vo, newsQueryVO);
            newsQueryVO.setAllSite(vo.getAllSite());
            newsQueryVO.setTypeCode(SolrPageQueryVO.TypeCode.articleNews.toString().concat(",")
                    .concat(SolrPageQueryVO.TypeCode.pictureNews.toString())
                    .concat(",").concat(SolrPageQueryVO.TypeCode.videoNews.toString()));
            Future<?> newsFuture = taskExecutor.submit(()->selectForAsk(map, sumMap, newsQueryVO, "news", context));

            //网上服务
            Future<?> workGuideFuture = taskExecutor.submit(()->selectForAsk(map, sumMap, vo, "workGuide", context));

            //留言
            SolrPageQueryVO messageBoardQueryVO = new SolrPageQueryVO();
            BeanUtil.copyProperties(vo, messageBoardQueryVO);
            messageBoardQueryVO.setAllSite(vo.getAllSite());
            messageBoardQueryVO.setTypeCode(SolrPageQueryVO.TypeCode.messageBoard.toString());
            Future<?> messageBoardFuture = taskExecutor.submit(()->selectForAsk(map, sumMap, messageBoardQueryVO, "messageBoard", context));

            //信息公开（isAllSite为true时，搜索所有集合，不区分集合和站点，只根据dn搜索，有区分需要的项目可以重写SearchEsServiceImpl类）
            SolrPageQueryVO publicContentQueryVO = new SolrPageQueryVO();
            BeanUtil.copyProperties(vo, publicContentQueryVO);
            publicContentQueryVO.setAllSite(vo.getAllSite());
            publicContentQueryVO.setTypeCode(SolrPageQueryVO.TypeCode.public_content.toString());
            Future<?> publicContentFuture = taskExecutor.submit(()->selectForAsk(map, sumMap, publicContentQueryVO, "public_content", context));


            //问答知识库（isAllSite为true时，搜索所有集合，不区分集合和站点，有区分需要的项目可以重写或传false）
            SolrPageQueryVO knowledgeBaseQueryVO = new SolrPageQueryVO();
            BeanUtil.copyProperties(vo, knowledgeBaseQueryVO);
            knowledgeBaseQueryVO.setAllSite(vo.getAllSite());
            knowledgeBaseQueryVO.setTypeCode(SolrPageQueryVO.TypeCode.knowledgeBase.toString());
            Future<?> knowledgeBaseFuture = taskExecutor.submit(()->selectForAsk(map, sumMap, knowledgeBaseQueryVO, "knowledgeBase", context));

            try {
                knowledgeBaseFuture.get();
            } catch (Exception e) {
                e.printStackTrace();
            }
            try {
                messageBoardFuture.get();
            } catch (Exception e) {
                e.printStackTrace();
            }
            try {
                newsFuture.get();
            } catch (Exception e) {
                e.printStackTrace();
            }
            try {
                publicContentFuture.get();
            } catch (Exception e) {
                e.printStackTrace();
            }
            try {
                workGuideFuture.get();
            } catch (Exception e) {
                e.printStackTrace();
            }

            tabcount = sumMap.values().size();
            map.put("tabcount", tabcount);
            map.put("numMap", sumMap);

 private void selectForAsk(Map<String, Object> map, Map<String, Object> sumMap, SolrPageQueryVO vo, String type, Context context) {
        if ("news".equals(type)) {
            try {
                // do something
            } catch (Exception e) {
                e.printStackTrace();
            }
        } else if ("workGuide".equals(type)) {
            try {
                //网上办事查询调用接口
               // do something
            } catch (Exception e) {
                e.printStackTrace();
            }
        } else if ("messageBoard".equals(type)) {
            try {
                // do something
            } catch (Exception e) {
                e.printStackTrace();
            }
        } else if ("public_content".equals(type)) {
            try {
                Long queryCount = SearchQueryHolder.queryCount(vo);
                // do something
            } catch (Exception e) {
                e.printStackTrace();
            }
        } else if ("knowledgeBase".equals(type)) {
            try {
                // do something
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

总结

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