线程池：第四章：ThreadPoolTaskExecutor和ThreadPoolExecutor有何区别?
线程池：第四章：ThreadPoolTaskExecutor和ThreadPoolExecutor有何区别?
Java廖志伟
发布于 2022-09-28 17:07:38
发布于 2022-09-28 17:07:38
- ThreadPoolTaskExecutor是spring core包中的，而ThreadPoolExecutor是JDK中的JUC。
- ThreadPoolTaskExecutor是对ThreadPoolExecutor进行了封装处理。
看看ThreadPoolTaskExecutor源码
看看ThreadPoolExecutor源码
public ThreadPoolExecutor(int corePoolSize,
int maximumPoolSize,
long keepAliveTime,
TimeUnit unit,
BlockingQueue<Runnable> workQueue,
ThreadFactory threadFactory,
RejectedExecutionHandler handler) {
if (corePoolSize < 0 ||
maximumPoolSize <= 0 ||
maximumPoolSize < corePoolSize ||
keepAliveTime < 0)
throw new IllegalArgumentException();
if (workQueue == null || threadFactory == null || handler == null)
throw new NullPointerException();
this.corePoolSize = corePoolSize;
this.maximumPoolSize = maximumPoolSize;
this.workQueue = workQueue;
this.keepAliveTime = unit.toNanos(keepAliveTime);
this.threadFactory = threadFactory;
this.handler = handler;
}int corePoolSize:线程池维护线程的最小数量.
int maximumPoolSize:线程池维护线程的最大数量.
long keepAliveTime:空闲线程的存活时间.
TimeUnit unit: 时间单位,现有纳秒,微秒,毫秒,秒枚举值.
BlockingQueue<Runnable> workQueue:持有等待执行的任务队列.
ThreadFactory:线程工厂
RejectedExecutionHandler handler:用来拒绝一个任务的执行
而拒绝策略有四种：
(1)ThreadPoolExecutor.AbortPolicy策略，是默认的策略,处理程序遭到拒绝将抛出运行时 RejectedExecutionException。
(2)ThreadPoolExecutor.CallerRunsPolicy策略 ,调用者的线程会执行该任务,如果执行器已关闭,则丢弃.
(3)ThreadPoolExecutor.DiscardPolicy策略，不能执行的任务将被丢弃.
(4)ThreadPoolExecutor.DiscardOldestPolicy策略，如果执行程序尚未关闭，则位于工作队列头部的任务将被删除，然后重试执行程序（如果再次失败，则重复此过程）.
上一章有详细讲解
那我们现在来用一用ThreadPoolTaskExecutor
弄一个工具类
package utils;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.ui.ModelMap;
import java.lang.reflect.Method;
import java.util.concurrent.CountDownLatch;
public class ThreadTool {
static ThreadPoolTaskExecutor threadPoolTaskExecutor;
static {
threadPoolTaskExecutor = new ThreadPoolTaskExecutor();
threadPoolTaskExecutor.setCorePoolSize(5);
threadPoolTaskExecutor.setMaxPoolSize(10);
threadPoolTaskExecutor.setQueueCapacity(100);
threadPoolTaskExecutor.initialize();
}
/**
* 使用线程池执行业务方法并加入视图
* @param tasks 计数器
* @param modelMap 视图
* @param modelName 视图名
* @param service 要调用的service
* @param method 被调用的方法
* @param param 方法参数
*/
public static void runMethod(CountDownLatch tasks, ModelMap modelMap, String modelName, Object service, Method method, Object... param){
threadPoolTaskExecutor.submit(new RunInThreadPool(
tasks,modelMap,modelName,service,method,param));
}
}RunInThreaddPool
package utils;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Map;
import java.util.concurrent.CountDownLatch;
public class RunInThreadPool implements Runnable {
CountDownLatch countDownLatch;
Map modelMap;
String keyName;
Object service;
Method method;
Object[] param;
/**
* @param countDownLatch 计数器
* @param modelMap 视图
* @param keyName 参数名
* @param service 要调用的service
* @param method 被调用的方法
* @param param 方法参数
*/
public RunInThreadPool(CountDownLatch countDownLatch, Map modelMap, String keyName, Object service, Method method, Object... param) {
this.countDownLatch = countDownLatch;
this.modelMap = modelMap;
this.keyName = keyName;
this.service = service;
this.method = method;
this.param = param;
}
@Override
public void run() {
Object result = null;
try {
Long start = System.currentTimeMillis();
result = method.invoke(service, param);
Long end = System.currentTimeMillis();
System.out.println(String.format("%s *** 执行 ((( %s ))) 方法,耗时 <<< %s 秒 >>> 参数",
service.getClass(),
method.getName(),
(end - start),
JsonUtils.toJson(param)));
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
modelMap.put(keyName, result);
countDownLatch.countDown();
}
}实战案例：
@RequestMapping("/goodsDetail")
public String goodsDetail(GoodsBean goodsBean, PageBean pageBean, ModelMap modelMap) throws Exception {
final CountDownLatch latch = new CountDownLatch(7);
Method getRelatedGoods = goodsService.getClass().getMethod("getRelatedGoods", GoodsBean.class, String.class);
getRelatedGoods.setAccessible(Boolean.TRUE);
ThreadTool.runMethod(latch , modelMap, "relatedGoods0", goodsService, getRelatedGoods, goodsBean, "0");
//剩下六个类似的业务。。。。
...............................
latch.await();
return "production/index";
}对比：
@RequestMapping("/getRelatedGoods")
@AppController
public String getRelatedGoods(GoodsBean goodsBean, String show_type,ModelMap modelMap) {
modelMap.addAttribute("getRelatedGoods",goodsService.getRelatedGoods(goodsBean, show_type));
return "production/index";
}本文参与 腾讯云自媒体同步曝光计划，分享自作者个人站点/博客。
原始发表：2021-04-28，如有侵权请联系 cloudcommunity@tencent.com 删除
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