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| package com.yibo.modules.empi;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class SynchronizedTest {
private static SynchronizedTest synchronizedTest = new SynchronizedTest();
private Boolean flag = true;
private SynchronizedTest() {
}
public static SynchronizedTest getInstance() {
return synchronizedTest;
}
public void test() {
synchronized (flag) {
if (flag) {
flag = false;
ExecutorService singleThreadExecutor = Executors.newSingleThreadExecutor();
singleThreadExecutor.execute(() -> {
try {
for (int i = 0; i < 3; i++) {
final int index = i;
System.out.println(index);
Thread.sleep(1000);
}
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
flag = true;
}
});
} else {
System.out.println("正在执行");
}
}
}
public static void main(String[] args) {
getInstance().test();
try {
Thread.sleep(1000);
getInstance().test();
Thread.sleep(2000);
getInstance().test();
Thread.sleep(4000);
getInstance().test();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
|