1.ExecutorService 

private static ExecutorService exec = null;

public static ExecutorService getExecutorServiceInstance(){
    if(exec == null){
        exec = Executors.newCachedThreadPool();
    }
    return exec;
}

public void threadNoticeOrMessageOrShortMessage (Integer type, Map<String, String> map, List<String> replaceParameter, List<String> list, Integer saveFlag){
    exec = getExecutorServiceInstance();
    NoticeOrMessageOrShortMessage noticeOrMessageOrShortMessage = new NoticeOrMessageOrShortMessage(getMessagePushInstance(), type, map, replaceParameter, list, saveFlag,
            messagePushService, sendPushService, sendSmsService, sendMessageService);
    exec.execute(noticeOrMessageOrShortMessage);
}

2.ThreadPoolTaskExecutor

<bean id="taskExecutor" class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
   <property name="corePoolSize" value="http://www.mamicode.com/${task.core_pool_size}" />
   <property name="maxPoolSize" value="http://www.mamicode.com/${task.max_pool_size}" />
   <property name="queueCapacity" value="http://www.mamicode.com/${task.queue_capacity}" />
   <property name="keepAliveSeconds" value="http://www.mamicode.com/${task.keep_alive_seconds}" />
　　<!-- 新增 -->

1. <!-- 线程池对拒绝任务(无线程可用)的处理策略 -->  
2.     <property name="rejectedExecutionHandler">  
3.       <bean class="java.util.concurrent.ThreadPoolExecutor$CallerRunsPolicy" />  
4.     </property>  

</bean>

@Resource(name = "taskExecutor")
private TaskExecutor taskExecutor;

private void addSendTask(final MimeMessage mimeMessage) {
   try {
      taskExecutor.execute(new Runnable() {
         public void run() {
            javaMailSender.send(mimeMessage);
         }
      });
   } catch (Exception e) {
      e.printStackTrace();
   }
}
另外一种方式(未验证代码准确性) 

private static ThreadPoolTaskExecutor threadPoolTaskExecutor = null;

public static ThreadPoolTaskExecutor getThreadPoolTaskExecutor Instance(){

    if(threadPoolTaskExecutor == null){
　　　　threadPoolTaskExecutor.setCorePoolSize(5);
　　　　threadPoolTaskExecutor.setMaxPoolSize(50);
　　　　threadPoolTaskExecutor.setQueueCapacity(1000);
　　　　threadPoolTaskExecutor.setKeepAliveSeconds(60);

　　　　try {
      　　taskExecutor.execute(new Runnable() {
        　　 public void run() {
            　　javaMailSender.send(mimeMessage);
         　　}
      　　});
   　　} catch (Exception e) {
            e.printStackTrace();
   　　}

　　　}

    return exec;
}

具体线程还是有些不懂

ExecutorService与ThreadPoolTaskExecutor