本文介绍了Spring线程池ThreadPoolTaskExecutor配置,分享给大家,具体如下:
1. ThreadPoolTaskExecutor配置
- <!-- spring thread pool executor -->
- <bean id="taskExecutor" class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
- <!-- 线程池维护线程的最少数量 -->
- <property name="corePoolSize" value="5" />
- <!-- 允许的空闲时间 -->
- <property name="keepAliveSeconds" value="200" />
- <!-- 线程池维护线程的最大数量 -->
- <property name="maxPoolSize" value="10" />
- <!-- 缓存队列 -->
- <property name="queueCapacity" value="20" />
- <!-- 对拒绝task的处理策略 -->
- <property name="rejectedExecutionHandler">
- <bean class="java.util.concurrent.ThreadPoolExecutor$CallerRunsPolicy" />
- </property>
- </bean>
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属性字段说明
corePoolSize:线程池维护线程的最少数量
keepAliveSeconds:允许的空闲时间
maxPoolSize:线程池维护线程的最大数量
queueCapacity:缓存队列
rejectedExecutionHandler:对拒绝task的处理策略
2. execute(Runable)方法执行过程
如果此时线程池中的数量小于corePoolSize,即使线程池中的线程都处于空闲状态,也要创建新的线程来处理被添加的任务。
如果此时线程池中的数量等于 corePoolSize,但是缓冲队列 workQueue未满,那么任务被放入缓冲队列。
如果此时线程池中的数量大于corePoolSize,缓冲队列workQueue满,并且线程池中的数量小于maxPoolSize,建新的线程来处理被添加的任务。
如果此时线程池中的数量大于corePoolSize,缓冲队列workQueue满,并且线程池中的数量等于maxPoolSize,那么通过handler所指定的策略来处理此任务。也就是:处理任务的优先级为:核心线程corePoolSize、任务队列workQueue、最大线程 maximumPoolSize,如果三者都满了,使用handler处理被拒绝的任务。
当线程池中的线程数量大于corePoolSize时,如果某线程空闲时间超过keepAliveTime,线程将被终止。这样,线程池可以动态的调整池中的线程数。
3. 示例代码
Junit Test
- @RunWith(SpringJUnit4ClassRunner.class)
- @ContextConfiguration(classes = { MultiThreadConfig.class })
- public class MultiThreadTest {
- @Autowired
- private ThreadPoolTaskExecutor taskExecutor;
- @Autowired
- private MultiThreadProcessService multiThreadProcessService;
-
- @Test
- public void test() {
- int n = 20;
- for (int i = 0; i < n; i++) {
- taskExecutor.execute(new MultiThreadDemo(multiThreadProcessService));
- System.out.println("int i is " + i + ", now threadpool active threads totalnum is " + taskExecutor.getActiveCount());
- }
-
- try {
- System.in.read();
- } catch (IOException e) {
- throw new RuntimeException(e);
- }
- }
- }
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MultiThreadDemo
- /**
- * 多线程并发处理demo
- * @author daniel.zhao
- *
- */
- public class MultiThreadDemo implements Runnable {
- private MultiThreadProcessService multiThreadProcessService;
- public MultiThreadDemo() {
- }
-
- public MultiThreadDemo(MultiThreadProcessService multiThreadProcessService) {
- this.multiThreadProcessService = multiThreadProcessService;
- }
-
- @Override
- public void run() {
- multiThreadProcessService.processSomething();
- }
- }
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MultiThreadProcessService
- @Service
- public class MultiThreadProcessService {
- public static final Logger logger = Logger.getLogger(MultiThreadProcessService.class);
-
- /**
- * 默认处理流程耗时1000ms
- */
- public void processSomething() {
- logger.debug("MultiThreadProcessService-processSomething" + Thread.currentThread() + "......start");
- try {
- Thread.sleep(1000);
- } catch (InterruptedException e) {
- throw new RuntimeException(e);
- }
- logger.debug("MultiThreadProcessService-processSomething" + Thread.currentThread() + "......end");
- }
- }
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MultiThreadConfig
- @Configuration
- @ComponentScan(basePackages = { "com.xxx.multithread" })
- @ImportResource(value = { "classpath:config/application-task.xml" })
- @EnableScheduling
- public class MultiThreadConfig {
- }
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以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持程序员之家。 |