java利用Future实现多线程执行与结果聚合实例代码
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();
}
}
}