add taskExecutorConf, add async annotation, add code comment

springWarehouse/src/main/java/com/yen/springWarehouse/WarehouseApplication.java

@@ -3,8 +3,10 @@
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.context.annotation.ComponentScan;
+import org.springframework.scheduling.annotation.Async;
 import org.springframework.transaction.annotation.EnableTransactionManagement;
 
+//@Async // enable async, let Spring auto do op with async
 @ComponentScan(basePackages = "com.yen.springWarehouse")
 @org.mybatis.spring.annotation.MapperScan("com.yen.springWarehouse.mapper")
 @EnableTransactionManagement // TODO : recheck this

springWarehouse/src/main/java/com/yen/springWarehouse/config/TaskExecutorConfig.java

@@ -0,0 +1,80 @@
+package com.yen.springWarehouse.config;
+
+// https://github.com/timebusker/spring-boot/blob/master/spring-boot-5-Async/src/main/java/cn/timebusker/config/TaskExecutorConfig.java
+
+import java.util.concurrent.Executor;
+import java.util.concurrent.ThreadPoolExecutor;
+
+import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.AsyncConfigurer;
+import org.springframework.scheduling.annotation.EnableAsync;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
+
+@Configuration
+@EnableAsync
+public class TaskExecutorConfig implements AsyncConfigurer{
+
+    /**
+     * Set the ThreadPoolExecutor's core pool size.
+     */
+    private static final int CORE_POOL_SIZE = 5;
+
+    /**
+     * Set the ThreadPoolExecutor's maximum pool size.
+     */
+    private static final int MAX_POOL_SIZE = 20;
+
+    /**
+     * Set the capacity for the ThreadPoolExecutor's BlockingQueue.
+     */
+    private static final int QUEUE_CAPACITY = 10;
+
+    /**
+     * 通过重写getAsyncExecutor方法，制定默认的任务执行由该方法产生
+     *
+     * 配置类实现AsyncConfigurer接口并重写getAsyncExcutor方法，并返回一个ThreadPoolTaskExevutor
+     * 这样我们就获得了一个基于线程池的TaskExecutor
+     */
+    @Override
+    public Executor getAsyncExecutor() {
+
+        System.out.println(">>> getAsyncExecutor ...");
+
+        ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
+        taskExecutor.setCorePoolSize(CORE_POOL_SIZE);// 线程池维护线程的最少数量
+        taskExecutor.setMaxPoolSize(MAX_POOL_SIZE);// 线程池维护线程的最大数量
+        taskExecutor.setQueueCapacity(QUEUE_CAPACITY);// 线程池所使用的缓冲队列
+        taskExecutor.initialize();
+
+        return taskExecutor;
+    }
+
+    @Override
+    public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
+        return null;
+    }
+
+    /**
+     * 自定义任务执行器：在定义了多个任务执行器的情况下，可以使用@Async("getMineAsync")来设定
+     *
+     * @return
+     */
+    @Bean
+    public Executor getMineAsync() {
+
+        System.out.println(">>> getMineAsync ... ");
+        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
+        executor.setCorePoolSize(CORE_POOL_SIZE - 4);
+        executor.setMaxPoolSize(MAX_POOL_SIZE - 10);
+        executor.setQueueCapacity(QUEUE_CAPACITY - 5);
+        executor.setThreadNamePrefix("mineAsync-");
+        // rejection-policy：当pool已经达到max size的时候，如何处理新任务
+        // CALLER_RUNS：不在新线程中执行任务，而是有调用者所在的线程来执行
+        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
+        executor.initialize();
+        return executor;
+    }
+
+}

springWarehouse/src/main/java/com/yen/springWarehouse/controller/DownloadController.java

@@ -65,12 +65,17 @@ public String list(Map<String, Object> map, @RequestParam(value="pageNo", requir
     }
 
     @GetMapping("/create_report")
-    public String createDownload() {
+    public String createDownload() throws InterruptedException {
 
         DateTimeUtils dateTimeUtils = new DateTimeUtils();
         String timestamp = dateTimeUtils.getCurrentDateYYYYMMDDHHMMSS();
         FileUtil fileUtil = new FileUtil();
 
+//        log.info("--------------------------------------------\n");
+//        log.info(">>>>>>>>> SLEEP 10 SECONDS >>>>>>>>>\n");
+//        Thread.sleep(10000);
+//        log.info("--------------------------------------------\n");
+
         // create report
         String fileName = timestamp + "_report.json";
         Map<String, Object> map = new HashMap<>();

springWarehouse/src/main/java/com/yen/springWarehouse/service/impl/DownloadStatusServiceImpl.java

@@ -4,6 +4,7 @@
 import com.yen.springWarehouse.bean.DownloadStatus;
 import com.yen.springWarehouse.mapper.DownloadStatusMapper;
 import com.yen.springWarehouse.service.DownloadStatusService;
+import org.springframework.scheduling.annotation.Async;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 

springWarehouse/src/main/java/com/yen/springWarehouse/service/impl/ProductTypeServiceImpl.java

@@ -8,13 +8,15 @@
 import com.yen.springWarehouse.mapper.ProductTypeMapper;
 import com.yen.springWarehouse.service.ProductTypeService;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.scheduling.annotation.Async;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
 // NOTE below !!!
 // -> we don't implement every abstract method in  ProductTypeService, but we extend ServiceImpl first
 // then implement rest of the abstract methods
 @Service
+//@Async("getMineAsync")
 @Transactional(rollbackFor = Exception.class)
 public class ProductTypeServiceImpl extends ServiceImpl<ProductTypeMapper, ProductType> implements ProductTypeService {