public class App {
public static void main( String[] args )
{
ExecutorService executorService = Executors.newCachedThreadPool();
List<String> dateStrList = Lists.newArrayList(
"2018-04-01 10:00:01",
"2018-04-02 11:00:02",
"2018-04-03 12:00:03",
"2018-04-04 13:00:04",
"2018-04-05 14:00:05"
);
final SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
for (final String str : dateStrList) {
executorService.execute(new Runnable() {
public void run() {
// TODO Auto-generated method stub
try {
System.out.println(simpleDateFormat.parse(str));
TimeUnit.SECONDS.sleep(1);
} catch ( Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
}
}
SimpleDateFormat是线程不安全的，需放在run()方法内部。或者考虑使用threadlocal封装，可参考 DateUtil
https://github.com/zxiaofan/JavaUtils/blob/master/src/com/zxiaofan/util/other/DateUtil.java
首先，这段代码运行时会产生这个运行时异常：
java.lang.NumberFormatException: multiple points
at sun.misc.FloatingDecimal.readJavaFormatString(Unknown Source)
根源就是 SimpleDateFormat 的线程不安全导致多线程共享该对象时产生了多指向问题。
其次，这里用了线程池提交任务，而任务执行完成后没有关闭线程池对象，导致程序存在资源泄露问题，应该等待所有任务执行完成后关闭线程池。
for (final String str : dateStrList) {
executorService.execute(new Runnable() {
public void run() {
try {
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println(simpleDateFormat.parse(str));
TimeUnit.SECONDS.sleep(1);
} catch ( Exception e) {
e.printStackTrace();
}
}
});
}
executorService.shutdown();