1. 為什么要異步
當我們開發中涉及短信發送，郵件發送等耗時請求時可以通過執行異步操作，從而加快請求響應，使用戶體驗更友好
2. 具體操作
創建springboot項目引入web和lombok包
完整的pom.xml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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.6.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>thread-pool-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>thread-pool-demo</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.10</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
2.1 配置application.yml
#線程池配置參數
task:
pool:
corePoolSize: 5 #設置核心線程數
maxPoolSize: 20 #設置最大線程數
keepAliveSeconds: 300 #設置線程活躍時間（秒）
queueCapacity: 50 #設置隊列容量
threadNamePrefix: # 線程名稱前綴
2.2 編寫線程池配置類
@ConfigurationProperties(prefix = "task.pool")
@Data
public class TaskThreadPoolConfig {
private int corePoolSize; // 核心線程數（默認線程數）
private int maxPoolSize; // 最大線程數
private int keepAliveTime; // 允許線程空閑時間（單位：默認為秒）
private int queueCapacity; // 緩沖隊列數
private String threadNamePrefix; // 線程池名前綴
}
2.3 在啟動類上開啟線程異步支持
@SpringBootApplication
@EnableAsync //開啟線程異步支持
@EnableConfigurationProperties({TaskThreadPoolConfig.class}) // 引入自定義線程池配置
public class ThreadPoolDemoApplication {
public static void main(String[] args) {
SpringApplication.run(ThreadPoolDemoApplication.class, args);
}
}
2.4 創建自定義線程池
@Configuration
public class MyThreadPoolTaskExecutor {
@Autowired
private TaskThreadPoolConfig config;
/**
* 默認異步線程池
*
* @return
*/
@Bean
public ThreadPoolTaskExecutor taskExecutor() {
ThreadPoolTaskExecutor pool = new ThreadPoolTaskExecutor();
pool.setThreadNamePrefix(config.getThreadNamePrefix());
pool.setCorePoolSize(config.getCorePoolSize());
pool.setMaxPoolSize(config.getMaxPoolSize());
pool.setKeepAliveSeconds(config.getKeepAliveTime());
pool.setQueueCapacity(config.getQueueCapacity());
// 直接在execute方法的調用線程中運行
pool.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
// 等待所有任務結束后再關閉線程池
pool.setWaitForTasksToCompleteOnShutdown(true);
// 初始化
pool.initialize();
return pool;
}
}
2.5 編寫測試Service和Controller
@Service
public class TaskService {
@Async
public void doTaskA() throws InterruptedException {
System.out.println("TaskA thread name->" + Thread.currentThread().getName() + "start");
Long startTime = System.currentTimeMillis();
TimeUnit.SECONDS.sleep(3);
Long endTime = System.currentTimeMillis();
System.out.println("TaskA thread name->" + Thread.currentThread().getName() + "finish");
System.out.println("TaskA 耗時：" + (endTime - startTime));
}
@Async
public void doTaskB() throws InterruptedException {
System.out.println("TaskB thread name->" + Thread.currentThread().getName() + "start");
Long startTime = System.currentTimeMillis();
TimeUnit.SECONDS.sleep(3);
Long endTime = System.currentTimeMillis();
System.out.println("TaskB thread name->" + Thread.currentThread().getName() + "finish");
System.out.println("TaskB耗時：" + (endTime - startTime));
}
}
@RestController
public class HelloController {
@Autowired
private TaskService taskService;
@GetMapping("/async")
public String testAsync() throws Exception {
System.out.println("主線程 name -->" + Thread.currentThread().getName() + "start");
Long startTime = System.currentTimeMillis();
taskService.doTaskA();
taskService.doTaskB();
Long endTime = System.currentTimeMillis();
System.out.println("主線程 name -->" + Thread.currentThread().getName() + "finish");
System.out.println("主線程" + Thread.currentThread().getName() + "耗時：" + (endTime - startTime));
return "Hello World";
}
}
測試結果
