springboot線程池的使用和擴展
我們常用ThreadPoolExecutor提供的線程池服務,springboot框架提供了@Async註解,幫助我們更方便的將業務邏輯提交到線程池中異步執行,今天我們就來實戰體驗這個線程池服務;
本文地址:http://blog.csdn.net/boling_cavalry/article/details/79120268
實戰環境
- windowns10;
- jdk1.8;
- springboot 1.5.9.RELEASE;
- 開發工具:IntelliJ IDEA;
實戰源碼
本次實戰的源碼可以在我的GitHub下載,地址:[email protected]:zq2599/blog_demos.git,項目主頁:https://github.com/zq2599/blog_demos
這裏面有多個工程,本次用到的工程為threadpooldemoserver,如下圖紅框所示:
實戰步驟梳理
本次實戰的步驟如下:
1. 創建springboot工程;
2. 創建Service層的接口和實現;
3. 創建controller,開發一個http服務接口,裏面會調用service層的服務;
4. 創建線程池的配置;
5. 將Service層的服務異步化,這樣每次調用都會都被提交到線程池異步執行;
6. 擴展ThreadPoolTaskExecutor,在提交任務到線程池的時候可以觀察到當前線程池的情況;
創建springboot工程
用IntelliJ IDEA創建一個springboot的web工程threadpooldemoserver,pom.xml內容如下:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.bolingcavalry</groupId>
<artifactId>threadpooldemoserver</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>threadpooldemoserver</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
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創建Service層的接口和實現
創建一個service層的接口AsyncService,如下:
public interface AsyncService {
/**
* 執行異步任務
*/
void executeAsync();
}
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對應的AsyncServiceImpl,實現如下:
@Service
public class AsyncServiceImpl implements AsyncService {
private static final Logger logger = LoggerFactory.getLogger(AsyncServiceImpl.class);
@Override
public void executeAsync() {
logger.info("start executeAsync");
try{
Thread.sleep(1000);
}catch(Exception e){
e.printStackTrace();
}
logger.info("end executeAsync");
}
}
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這個方法做的事情很簡單:sleep了一秒鐘;
創建controller
創建一個controller為Hello,裏面定義一個http接口,做的事情是調用Service層的服務,如下:
@RestController
public class Hello {
private static final Logger logger = LoggerFactory.getLogger(Hello.class);
@Autowired
private AsyncService asyncService;
@RequestMapping("/")
public String submit(){
logger.info("start submit");
//調用service層的任務
asyncService.executeAsync();
logger.info("end submit");
return "success";
}
}
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至此,我們已經做好了一個http請求的服務,裏面做的事情其實是同步的,接下來我們就開始配置springboot的線程池服務,將service層做的事情都提交到線程池中去處理;
springboot的線程池配置
創建一個配置類ExecutorConfig,用來定義如何創建一個ThreadPoolTaskExecutor,要使用@Configuration和@EnableAsync這兩個註解,表示這是個配置類,並且是線程池的配置類,如下所示:
@Configuration
@EnableAsync
public class ExecutorConfig {
private static final Logger logger = LoggerFactory.getLogger(ExecutorConfig.class);
@Bean
public Executor asyncServiceExecutor() {
logger.info("start asyncServiceExecutor");
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
//配置核心線程數
executor.setCorePoolSize(5);
//配置最大線程數
executor.setMaxPoolSize(5);
//配置隊列大小
executor.setQueueCapacity(99999);
//配置線程池中的線程的名稱前綴
executor.setThreadNamePrefix("async-service-");
// rejection-policy:當pool已經達到max size的時候,如何處理新任務
// CALLER_RUNS:不在新線程中執行任務,而是有調用者所在的線程來執行
executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
//執行初始化
executor.initialize();
return executor;
}
}
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註意,上面的方法名稱為asyncServiceExecutor,稍後馬上用到;
將Service層的服務異步化
打開AsyncServiceImpl.java,在executeAsync方法上增加註解@Async(“asyncServiceExecutor”),asyncServiceExecutor是前面ExecutorConfig.java中的方法名,表明executeAsync方法進入的線程池是asyncServiceExecutor方法創建的,如下:
@Override
@Async("asyncServiceExecutor")
public void executeAsync() {
logger.info("start executeAsync");
try{
Thread.sleep(1000);
}catch(Exception e){
e.printStackTrace();
}
logger.info("end executeAsync");
}
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驗證效果
- 將這個springboot運行起來(pom.xml所在文件夾下執行mvn spring-boot:run);
- 在瀏覽器輸入:http://localhost:8080;
- 在瀏覽器用F5按鈕快速多刷新幾次;
- 在springboot的控制臺看見日誌如下:
2018-01-21 22:43:18.630 INFO 14824 --- [nio-8080-exec-8] c.b.t.controller.Hello : start submit
2018-01-21 22:43:18.630 INFO 14824 --- [nio-8080-exec-8] c.b.t.controller.Hello : end submit
2018-01-21 22:43:18.929 INFO 14824 --- [async-service-1] c.b.t.service.impl.AsyncServiceImpl : end executeAsync
2018-01-21 22:43:18.930 INFO 14824 --- [async-service-1] c.b.t.service.impl.AsyncServiceImpl : start executeAsync
2018-01-21 22:43:19.005 INFO 14824 --- [async-service-2] c.b.t.service.impl.AsyncServiceImpl : end executeAsync
2018-01-21 22:43:19.006 INFO 14824 --- [async-service-2] c.b.t.service.impl.AsyncServiceImpl : start executeAsync
2018-01-21 22:43:19.175 INFO 14824 --- [async-service-3] c.b.t.service.impl.AsyncServiceImpl : end executeAsync
2018-01-21 22:43:19.175 INFO 14824 --- [async-service-3] c.b.t.service.impl.AsyncServiceImpl : start executeAsync
2018-01-21 22:43:19.326 INFO 14824 --- [async-service-4] c.b.t.service.impl.AsyncServiceImpl : end executeAsync
2018-01-21 22:43:19.495 INFO 14824 --- [async-service-5] c.b.t.service.impl.AsyncServiceImpl : end executeAsync
2018-01-21 22:43:19.930 INFO 14824 --- [async-service-1] c.b.t.service.impl.AsyncServiceImpl : end executeAsync
2018-01-21 22:43:20.006 INFO 14824 --- [async-service-2] c.b.t.service.impl.AsyncServiceImpl : end executeAsync
2018-01-21 22:43:20.191 INFO 14824 --- [async-service-3] c.b.t.service.impl.AsyncServiceImpl : end executeAsync
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如上日誌所示,我們可以看到controller的執行線程是”nio-8080-exec-8”,這是tomcat的執行線程,而service層的日誌顯示線程名為“async-service-1”,顯然已經在我們配置的線程池中執行了,並且每次請求中,controller的起始和結束日誌都是連續打印的,表明每次請求都快速響應了,而耗時的操作都留給線程池中的線程去異步執行;
擴展ThreadPoolTaskExecutor
雖然我們已經用上了線程池,但是還不清楚線程池當時的情況,有多少線程在執行,多少在隊列中等待呢?這裏我創建了一個ThreadPoolTaskExecutor的子類,在每次提交線程的時候都會將當前線程池的運行狀況打印出來,代碼如下:
public class VisiableThreadPoolTaskExecutor extends ThreadPoolTaskExecutor {
private static final Logger logger = LoggerFactory.getLogger(VisiableThreadPoolTaskExecutor.class);
private void showThreadPoolInfo(String prefix){
ThreadPoolExecutor threadPoolExecutor = getThreadPoolExecutor();
if(null==threadPoolExecutor){
return;
}
logger.info("{}, {},taskCount [{}], completedTaskCount [{}], activeCount [{}], queueSize [{}]",
this.getThreadNamePrefix(),
prefix,
threadPoolExecutor.getTaskCount(),
threadPoolExecutor.getCompletedTaskCount(),
threadPoolExecutor.getActiveCount(),
threadPoolExecutor.getQueue().size());
}
@Override
public void execute(Runnable task) {
showThreadPoolInfo("1. do execute");
super.execute(task);
}
@Override
public void execute(Runnable task, long startTimeout) {
showThreadPoolInfo("2. do execute");
super.execute(task, startTimeout);
}
@Override
public Future<?> submit(Runnable task) {
showThreadPoolInfo("1. do submit");
return super.submit(task);
}
@Override
public <T> Future<T> submit(Callable<T> task) {
showThreadPoolInfo("2. do submit");
return super.submit(task);
}
@Override
public ListenableFuture<?> submitListenable(Runnable task) {
showThreadPoolInfo("1. do submitListenable");
return super.submitListenable(task);
}
@Override
public <T> ListenableFuture<T> submitListenable(Callable<T> task) {
showThreadPoolInfo("2. do submitListenable");
return super.submitListenable(task);
}
}
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如上所示,showThreadPoolInfo方法中將任務總數、已完成數、活躍線程數,隊列大小都打印出來了,然後Override了父類的execute、submit等方法,在裏面調用showThreadPoolInfo方法,這樣每次有任務被提交到線程池的時候,都會將當前線程池的基本情況打印到日誌中;
修改ExecutorConfig.java的asyncServiceExecutor方法,將ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor()改為ThreadPoolTaskExecutor executor = new VisiableThreadPoolTaskExecutor(),如下所示:
@Bean
public Executor asyncServiceExecutor() {
logger.info("start asyncServiceExecutor");
//使用VisiableThreadPoolTaskExecutor
ThreadPoolTaskExecutor executor = new VisiableThreadPoolTaskExecutor();
//配置核心線程數
executor.setCorePoolSize(5);
//配置最大線程數
executor.setMaxPoolSize(5);
//配置隊列大小
executor.setQueueCapacity(99999);
//配置線程池中的線程的名稱前綴
executor.setThreadNamePrefix("async-service-");
// rejection-policy:當pool已經達到max size的時候,如何處理新任務
// CALLER_RUNS:不在新線程中執行任務,而是有調用者所在的線程來執行
executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
//執行初始化
executor.initialize();
return executor;
}
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再次啟動該工程,再瀏覽器反復刷新http://localhost:8080,看到的日誌如下:
2018-01-21 23:04:56.113 INFO 15580 --- [nio-8080-exec-1] c.b.t.e.VisiableThreadPoolTaskExecutor : async-service-, 2. do submit,taskCount [99], completedTaskCount [85], activeCount [5], queueSize [9]
2018-01-21 23:04:56.113 INFO 15580 --- [nio-8080-exec-1] c.b.t.controller.Hello : end submit
2018-01-21 23:04:56.225 INFO 15580 --- [async-service-1] c.b.t.service.impl.AsyncServiceImpl : end executeAsync
2018-01-21 23:04:56.225 INFO 15580 --- [async-service-1] c.b.t.service.impl.AsyncServiceImpl : start executeAsync
2018-01-21 23:04:56.240 INFO 15580 --- [nio-8080-exec-2] c.b.t.controller.Hello : start submit
2018-01-21 23:04:56.240 INFO 15580 --- [nio-8080-exec-2] c.b.t.e.VisiableThreadPoolTaskExecutor : async-service-, 2. do submit,taskCount [100], completedTaskCount [86], activeCount [5], queueSize [9]
2018-01-21 23:04:56.240 INFO 15580 --- [nio-8080-exec-2] c.b.t.controller.Hello : end submit
2018-01-21 23:04:56.298 INFO 15580 --- [async-service-2] c.b.t.service.impl.AsyncServiceImpl : end executeAsync
2018-01-21 23:04:56.298 INFO 15580 --- [async-service-2] c.b.t.service.impl.AsyncServiceImpl : start executeAsync
2018-01-21 23:04:56.372 INFO 15580 --- [nio-8080-exec-3] c.b.t.controller.Hello : start submit
2018-01-21 23:04:56.373 INFO 15580 --- [nio-8080-exec-3] c.b.t.e.VisiableThreadPoolTaskExecutor : async-service-, 2. do submit,taskCount [101], completedTaskCount [87], activeCount [5], queueSize [9]
2018-01-21 23:04:56.373 INFO 15580 --- [nio-8080-exec-3] c.b.t.controller.Hello : end submit
2018-01-21 23:04:56.444 INFO 15580 --- [async-service-3] c.b.t.service.impl.AsyncServiceImpl : end executeAsync
2018-01-21 23:04:56.445 INFO 15580 --- [async-service-3] c.b.t.service.impl.AsyncServiceImpl : start executeAsync
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註意這一行日誌:2. do submit,taskCount [101], completedTaskCount [87], activeCount [5], queueSize [9]
這說明提交任務到線程池的時候,調用的是submit(Callable task)這個方法,當前已經提交了101個任務,完成了87個,當前有5個線程在處理任務,還剩9個任務在隊列中等待,線程池的基本情況一路了然;
至此,springboot線程池服務的實戰就完成了,希望能幫您在工程中快速實現異步服務;
springboot線程池的使用和擴展