Because the mailbox to send very slow, generally better than a few seconds to send an e-mail QQ, I wrote a mail queue, with a thread to send mail, here's a simulated case.
This case simulates a mail sending process. EmailQueueSendUtils contains a message queue, after the start of the EmailQueueSendUtils, mail queue will automatically detect whether there are messages, if any, will be sent, otherwise it will wait for a new message to notify blocked thread.
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
public class Test2{
public static void main(String[] args) throws InterruptedException {
EmailQueueSendUtils emailQueueSendUtils = new EmailQueueSendUtils(new ArrayList<>());
new Thread(emailQueueSendUtils, "1").start();
new Thread(emailQueueSendUtils, "2").start();
for (int i = 0; i < 50; i++) {
emailQueueSendUtils.addEmailTask(i);
}
TimeUnit.SECONDS.sleep(10);
System.exit(0);
}
}
class EmailQueueSendUtils implements Runnable{
private final List<Integer> emailEntityList;
public EmailQueueSendUtils(List<Integer> emailEntityList){
this.emailEntityList = emailEntityList;
}
@Override
public void run() {
while (true){
System.out.println("进入线程"+Thread.currentThread().getName());
synchronized (emailEntityList){
//是否有邮件
if(emailEntityList.size()>0){
while(emailEntityList.size()>0) {
Integer emailEntity = emailEntityList.remove(0);
System.out.println(Thread.currentThread().getName() + ", " + emailEntity + ", size: " + emailEntityList.size());
}
//输出完,等待
try {
emailEntityList.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}else {
try {
emailEntityList.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}
public void addEmailTask(Integer emailEntity){
synchronized (emailEntityList) {
System.out.println("NUM: "+emailEntity+", 线程:"+Thread.currentThread().getName());
emailEntityList.add(emailEntity);
emailEntityList.notify();
}
}
}