4.3.8 线程池使用
Koupleless 线程池使用
背景
当多个模块或模块和基座共用一个线程池时，由于线程池执行任务使用的线程 Classloader 可能和创建该任务时使用的 Classloader 不一致，从而导致线程池执行任务时出现 ClassNotFound 异常。
因此，当多个模块或模块和基座共用一个线程池时，为了保持线程池执行任务时使用的 Classloader 和创建该任务时使用的 Classloader 一致，我们需要对线程池做一些修改。
⚠️注意：各模块使用各自的线程池，不会有此问题。
java常用的线程池使用方式有4种：
- 直接创建线程任务，提交到线程池中，如：Runnable, Callable, ForkJoinTask
- 自定义ThreadPoolExecutor，并提交到 ThreadPoolExecutor
- 通过 Executors 创建线程池，并提交到 ExecutorService, ScheduledExecutorService, ForkJoinPool
- SpringBoot 用户提交到 ThreadPoolTaskExecutor, SchedulerThreadPoolTaskExecutor
本文将介绍每一种方式在 Koupleless 上的使用方式。
使用方式
1. 直接创建线程任务，提交到线程池中
原来的方式：
threadPool.execute(new Runnable(){
public void run() {
//do something
}
});
threadPool.execute(new Callable<String>(){
public String call() {
//do something
return "mock";
}
});
如果保持 threadPool 不变，则需要将 Runnable 包装成 KouplelessRunnable，将 Callable 包装成 KouplelessCallable，如下：
// Runnable
// wrap方法
threadPool.execute(KouplelessRunnable.wrap(new Runnable(){
public void run() {
//do something
}
});
// 或者直接new KouplelessRunnable
threadPool.execute(new KouplelessRunnable(){
public void run() {
//do something
}
});
// Runnable
// wrap方法
threadPool.execute(KouplelessCallable.wrap(new Callable<String>(){
public String call() {
//do something
return "mock";
}
});
// 或者直接new KouplelessRunnable
threadPool.execute(new KouplelessCallable<String>(){
public String call() {
//do something
return "mock";
}
});
2. 自定义ThreadPoolExecutor
原来的方式：
ThreadPoolExecutor threadPool = new ThreadPoolExecutor(5, 5, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>());
threadPool.execute(new Runnable(){
public void run() {
//do something
}
});
threadPool.execute(new Callable<String>(){
public String call() {
//do something
return "mock";
}
});
如果要保持 Runnable 和 Callable 不变，则有两种改造方式：
- 将 threadPool 修改为 KouplelessThreadPoolExecutor
- 或者使用 kouplelessExecutorService。
首先，举例第一种改造方式：将 threadPool 修改为 KouplelessThreadPoolExecutor。如下：
// 将 ThreadPoolExecutor 修改为 KouplelessThreadPoolExecutor
ThreadPoolExecutor threadPool = new KouplelessThreadPoolExecutor(5, 5, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>());
threadPool.execute(new Runnable(){
public void run() {
//do something
}
});
threadPool.execute(new Callable<String>(){
public String call() {
//do something
return "mock";
}
});
然后，举例第二种改造方式：使用 kouplelessExecutorService。如下：
// 使用 KouplelessExecutorService
ExecutorService executor = new KouplelessExecutorService(new ThreadPoolExecutor(5, 5, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>()));
// 用 executor 执行任务
executor.execute(new Runnable(){
public void run() {
//do something
}
});
executor.execute(new Callable<String>(){
public String call() {
//do something
return "mock";
}
});
3. 使用二方包中的 ThreadPoolExecutor 或 ScheduledThreadPoolExecutor
原来的方式：
ThreadPoolExecutorA executorService = new ThreadPoolExecutorA();
executorService.execute(new Runnable(){
public void run() {
//do something
}
});
executorService.execute(new Callable<String>(){
public String call() {
//do something
return "mock";
}
});
ScheduledThreadPoolExecutorA scheduledExecutorService = new ScheduledThreadPoolExecutorA();
scheduledExecutorService.execute(new Runnable(){
public void run() {
//do something
}
});
scheduledExecutorService.execute(new Callable<String>(){
public String call() {
//do something
return "mock";
}
});
如果要保持 Runnable 和 Callable 不变，则需要使用 kouplelessExecutorService, kouplelessScheduledExecutorService，如下：
// 使用 KouplelessExecutorService
ExecutorService executor = new KouplelessExecutorService(new ThreadPoolExecutorA());
// 用 executor 执行任务
executor.execute(new Runnable(){
public void run() {
//do something
}
});
executor.execute(new Callable<String>(){
public String call() {
//do something
return "mock";
}
});
// 使用 KouplelessScheduledExecutorService
ScheduledExecutorService scheduledExecutor = new KouplelessScheduledExecutorService(new ScheduledThreadPoolExecutorA());
// 用 scheduledExecutor 执行任务
scheduledExecutor.execute(new Runnable(){
public void run() {
//do something
}
});
scheduledExecutor.execute(new Callable<String>(){
public String call() {
//do something
return "mock";
}
});
4. 通过 Executors 创建线程池
原来的方式：
ExecutorService executorService = Executors.newFixedThreadPool(6);
executorService.execute(new Runnable(){
public void run() {
//do something
}
});
executorService.execute(new Callable<String>(){
public String call() {
//do something
return "mock";
}
});
ScheduledExecutorService scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
scheduledExecutorService.execute(new Runnable(){
public void run() {
//do something
}
});
scheduledExecutorService.execute(new Callable<String>(){
public String call() {
//do something
return "mock";
}
});
如果要保持 Runnable 和 Callable 不变，则需要使用 kouplelessExecutorService, kouplelessScheduledExecutorService，如下：
// 使用 KouplelessExecutorService
ExecutorService executor = new KouplelessExecutorService(Executors.newFixedThreadPool(6));
// 用 executor 执行任务
executor.execute(new Runnable(){
public void run() {
//do something
}
});
executor.execute(new Callable<String>(){
public String call() {
//do something
return "mock";
}
});
// 使用 KouplelessScheduledExecutorService
ScheduledExecutorService scheduledExecutor = new KouplelessScheduledExecutorService(Executors.newSingleThreadScheduledExecutor());
// 用 scheduledExecutor 执行任务
scheduledExecutor.execute(new Runnable(){
public void run() {
//do something
}
});
scheduledExecutor.execute(new Callable<String>(){
public String call() {
//do something
return "mock";
}
});
5. SpringBoot 用户提交到 ThreadPoolTaskExecutor, SchedulerThreadPoolTaskExecutor
由于 koupeless 已经对 springboot(2.3.0-2.7.x) 的 ThreadPoolTaskExecutor 和 SchedulerThreadPoolTaskExecutor 做了适配，所以可以直接使用。
@Autowired
private ThreadPoolTaskExecutor threadPoolTaskExecutor;
@Autowired
private SchedulerThreadPoolTaskExecutor schedulerThreadPoolTaskExecutor;
threadPoolTaskExecutor.execute(new Runnable(){
public void run() {
//do something
}
});
schedulerThreadPoolTaskExecutor.execute(new Runnable(){
public void run() {
//do something
}
});
Feedback
Was this page helpful?
Welcome propose feedback to community!
Welcome propose feedback to community, or improve this document directly.。
最后修改 2024.14.11: Update module-startup.md (39aeb80)