springboot自帶線程池怎么實(shí)現(xiàn)
本文講解"springboot自帶線程池如何實(shí)現(xiàn)"，希望能夠解決相關(guān)問題。
一: threadpooltaskexecuto
1 threadpooltaskexecutor線程池:
threadpooltaskexecutor是spring基于java本身的線程池threadpoolexecutor做的二次封裝，主要目的還是為了更加方便的在spring框架體系中使用線程池, 是spring中默認(rèn)的線程池
2 使用threadpooltaskexecutor注入bean到ioc中
? 配置文件形式,spring會(huì)自動(dòng)配置
##?默認(rèn)線程池配置,threadpooltaskexecutor? #?核心線程數(shù) spring.task.execution.pool.core-size=8?? #?最大線程數(shù) spring.task.execution.pool.max-size=16 #?空閑線程存活時(shí)間 spring.task.execution.pool.keep-alive=60s #?是否允許核心線程超時(shí) spring.task.execution.pool.allow-core-thread-timeout=true #?線程隊(duì)列數(shù)量 spring.task.execution.pool.queue-capacity=100 #?線程關(guān)閉等待 spring.task.execution.shutdown.await-termination=false spring.task.execution.shutdown.await-termination-period= #?線程名稱前綴 spring.task.execution.thread-name-prefix=demo_thread
配置形式:
import?org.springframework.beans.factory.annotation.value;
import?org.springframework.context.annotation.bean;
import?org.springframework.context.annotation.configuration;
import?org.springframework.scheduling.concurrent.threadpooltaskexecutor;
import?org.springframework.scheduling.concurrent.threadpooltaskscheduler;
import?java.util.concurrent.concurrenthashmap;
import?java.util.concurrent.concurrentmap;
import?java.util.concurrent.executor;
import?java.util.concurrent.scheduledfuture;
//@configuration
public?class?threadconfig?{
????@value("${task.maxpoolsize}")
????private?int?maxpoolsize;
????//todo?其他的相關(guān)配置都可以通過配置文件中注入
????@bean("threadpooltaskexecutor")
????public?executor?myasync()?{
????????final?threadpooltaskexecutor?executor?=
????????????????new?threadpooltaskexecutor();
????????executor.setmaxpoolsize(maxpoolsize);
????????//todo??其他參數(shù)設(shè)置
????????//初始化
????????executor.initialize();
????????return?executor;
????}
}3 創(chuàng)建線程后全部從ioc中獲取線程池子
4 線程池處理流程:
(1) 查看核心線程池是否已滿,不滿就創(chuàng)建一條線程執(zhí)行任務(wù),核心線程數(shù)量已滿就查看任務(wù)隊(duì)列是否已滿不滿就將線程存儲(chǔ)在任務(wù)隊(duì)列中任務(wù)隊(duì)列已滿,就查看最大線程數(shù)量,不滿就創(chuàng)建線程執(zhí)行任務(wù),已滿就按照拒絕策略執(zhí)行
(2) 拒絕策略:
- callerrunspolicy():原來的線程執(zhí)行
- abortpolicy():直接拋出異常
- discardpolicy():直接丟棄
- discardoldestpolicy():丟棄隊(duì)列中最老的任
二: threadpooltaskscheduler?
1 threadpooltaskscheduler 定時(shí)調(diào)度任務(wù)線程池,處理異步任務(wù)
2 使用方式: 注入 threadpooltaskscheduler的bean
?(1) 配置文件形式:..
?(2) 配置類形式:
import?org.springframework.context.annotation.bean;
import?org.springframework.context.annotation.configuration;
import?org.springframework.scheduling.concurrent.threadpooltaskscheduler;
import?java.util.concurrent.concurrenthashmap;
import?java.util.concurrent.concurrentmap;
import?java.util.concurrent.scheduledfuture;
@configuration
public?class?threadpooltaskschedulerconfig?{
????@bean
????public?threadpooltaskscheduler?threadpooltaskscheduler()?{
????????final?threadpooltaskscheduler?threadpooltaskscheduler?=?new?threadpooltaskscheduler();
????????//設(shè)置等待任務(wù)在關(guān)機(jī)時(shí)l候完成
????????threadpooltaskscheduler.setwaitfortaskstocompleteonshutdown(true);
????????//設(shè)置等待時(shí)間為60s
????????threadpooltaskscheduler.setawaitterminationseconds(60);
????????return?threadpooltaskscheduler;
????}
}3 ?使用threadpooltaskscheduler定時(shí)任務(wù)
做普通線程池使用:
- ?submit(callable),需要執(zhí)行結(jié)果
- ?submit(runnable),不需要執(zhí)行結(jié)果
(1) 定時(shí)任務(wù)
?添加任務(wù)內(nèi)容runnable,設(shè)置執(zhí)行周期trigger/date,trigger表達(dá)式百度即可
?schedule(runnable?task,trigger) ?schedule(runnable?task,date)
(2) 指定間隔時(shí)間執(zhí)行一次任務(wù),時(shí)間間隔是前一次任務(wù)完成到下一次任務(wù)開始,單位毫秒
?schedulewithfixeddelay(runnable?task,long?delay)
(3) 固定頻率執(zhí)行任務(wù),在任務(wù)開始后間隔一段時(shí)間執(zhí)行新的任務(wù),如果上次任務(wù)么執(zhí)行完成,則等待上次任務(wù)執(zhí)行完成后執(zhí)行下次任務(wù)
?scheduleatfixedrate(runnable?task,long?delay)
(4) 定時(shí)任務(wù)取消:
設(shè)置定時(shí)任務(wù)存儲(chǔ)的集合,定時(shí)任務(wù)執(zhí)行的結(jié)果為scheduledfuture<?>,將該對象存儲(chǔ)到集合,通過在集合中獲取scheduledfuture<?>對象.cancel(true)取消定時(shí)任務(wù)
import?org.springframework.beans.factory.annotation.autowired;
import?org.springframework.scheduling.concurrent.threadpooltaskscheduler;
import?org.springframework.scheduling.support.crontrigger;
import?org.springframework.stereotype.service;
import?java.text.dateformat;
import?java.text.parseexception;
import?java.text.simpledateformat;
import?java.util.date;
import?java.util.concurrent.*;
@service
public?class?schedulerservice?{
????@autowired
????threadpooltaskscheduler?scheduler;
????/**
?????*?常規(guī)線程池使用
?????*/
????public?void?tesscheduler1()?throws?executionexception,?interruptedexception?{
????????//無返回值
????????final?future<?>?demo_scheduler1?=?scheduler.submit(new?runnable()?{
????????????@override
????????????public?void?run()?{
????????????????system.out.println("demo?runnable?scheduler");
????????????}
????????});
????????//無返回值
????????final?future<?>?demo_scheduler2?=?scheduler.submit(new?callable<object>()?{
????????????@override
????????????public?object?call()?throws?exception?{
????????????????system.out.println("demo?callable??scheduler");
????????????????return?"callable";
????????????}
????????});
????????system.out.println("result:"?+?demo_scheduler2.get());
????}
????/**
?????*?定時(shí)任務(wù)
?????*/
????public?void?tesscheduler2()?throws?parseexception?{
????????//crontrigger表達(dá)式百度即可
????????scheduler.schedule(()?->?{
????????????system.out.println("定時(shí)任務(wù)");
????????},?new?crontrigger("0/1****?"));
????????//創(chuàng)建指定時(shí)間的日期
????????final?date?date?=?new?date(2023,?3,?26,?21,?35);
????????final?dateformat?format?=?new?simpledateformat();
????????final?date?parse?=?format.parse("2023-03-26-21-26");
????????scheduler.schedule(()?->?{
????????????system.out.println(new?date());
????????},?parse);
????}
????/**
?????*?指定時(shí)間間隔執(zhí)行任務(wù),上次任務(wù)結(jié)束到下次任務(wù)開始的時(shí)間間隔
?????*/
????public?void?tesscheduler3()?{
????????scheduler.schedulewithfixeddelay(()?->?{
????????????//todo
????????},?300l);
????}
????/**
?????*?固定頻率執(zhí)行任務(wù),在固定一段時(shí)間后便會(huì)執(zhí)行下次任務(wù),
?????*?如果時(shí)間到了上次任務(wù)還沒執(zhí)行完畢則等待,
?????*?直到上一次任務(wù)執(zhí)行完畢后立馬執(zhí)行下次任務(wù)
?????*/
????public?void?tesscheduler4()?{
????????scheduler.scheduleatfixedrate(new?futuretask<string>(new?callable<string>()?{
????????????????????@override
????????????????????public?string?call()?throws?exception?{
????????????????????????return?null;
????????????????????}
????????????????}),
????????????????200);
????}
????//取消定時(shí)任務(wù)隊(duì)列
????public?static?concurrentmap<string,?scheduledfuture>?map?=?new?concurrenthashmap<>();
????public?void?starttask(string?k1)?{
????????map.compute(k1,?(k,?v)?->?{
????????????if?(map.containskey(k))?return?v;
????????????map.put(k,?v);
????????????return?v;
????????});
????}
}三 @scheduled實(shí)現(xiàn)定時(shí)任務(wù),注解開啟定時(shí)任務(wù)
1 使用@enablescheduled開啟支持
2 @scheduled標(biāo)注方法
?(1)@scheduled(fixeddelay=5000)延遲執(zhí)行,5s后執(zhí)行
?(2)@scheduled(fixedrate=5000)定時(shí)執(zhí)行,每隔五秒就進(jìn)行執(zhí)行
?(3)@scheduled(corn="002**?") 自定義執(zhí)行,corn表達(dá)式百度,常用這種執(zhí)行方式,corn="002**?"每天凌晨兩點(diǎn)開始執(zhí)行定時(shí)任務(wù)
3 注意@scheduled開啟的任務(wù)是單線程的,容易阻塞
?(1) 在ioc中注入threadpooltaskscheduler,則scheduled就使用threadpooltaskscheduler線程池,可以解決單線程阻塞問題
?(2) @scheduled和@async注解開啟定時(shí)任務(wù),在@async("pool")中指定線程池,若是沒有指定線程池會(huì)使用spring的simpleasynctaskexecutor線程池,這個(gè)線程池每次都會(huì)增加一個(gè)線程去執(zhí)行任務(wù),效率低下
四:spring中的異步任務(wù)
1 @enableasync開啟異步支持
2 @async開啟異步任務(wù),指定線程池
注意:@scheduled和@async注解開啟定時(shí)任務(wù),在@async("pool")中指定線程池,若是沒有指定線程池會(huì)使用spring的simpleasynctaskexecutor線程池,這個(gè)線程池每次都會(huì)增加一個(gè)線程去執(zhí)行任務(wù),效率低下但是@async單獨(dú)開啟異步任務(wù),則使用的是默認(rèn)的線程池,建議根據(jù)需求自定義線程池
注意:@async的返回值只能為void或future, 調(diào)用方和@async不能在一個(gè)類中,否則不走aop；
import?org.springframework.scheduling.annotation.async;
import?org.springframework.stereotype.service;
@service
public?class?asyncservice?{
????@async
????public?void?showthreadname1()?{
????????//默認(rèn)線程池
????????system.out.println(thread.currentthread().getname());
????}
????@async("mypool")//指定線程池
????public?void?showthreadname2()?{
????????system.out.println(thread.currentthread().getname());
????}
}五:獻(xiàn)上一顆自java自定義線程池:
?@bean("mypool")
????public?executor?executor(){
???????return?new?threadpoolexecutor(//?自定義一個(gè)線程池
????????????????1,?//?coresize
????????????????2,?//?maxsize
????????????????60,?//?60s
????????????????timeunit.seconds,?new?arrayblockingqueue<>(3)?//?有界隊(duì)列，容量是3個(gè)
????????????????,?executors.defaultthreadfactory()
????????????????,?new?threadpoolexecutor.abortpolicy());
????}java自帶的線程池,緩存,固定數(shù)量的,單線程的,定時(shí)的,,,,六七種,后面續(xù)上
關(guān)于 "springboot自帶線程池如何實(shí)現(xiàn)" 就介紹到此。希望多多支持碩編程。
Java技巧