(转)SimpleDateFormat非线程安全

SimpleDateFormat非线程安全

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package tdh.common;import java.text.SimpleDateFormat;import java.util.Date;public class Test {  public static void main(String[] args) {    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");    Date today = new Date();    Date tomorrow = new Date(today.getTime() + 1000 * 60 * 60 * 24);    System.out.println(today); // 今天是2011-10-24    System.out.println(tomorrow); // 明天是2011-10-25    Thread thread1 = new Thread(new Thread1(dateFormat, today));    thread1.start();    Thread thread2 = new Thread(new Thread2(dateFormat, tomorrow));    thread2.start();  }  }class Thread1 implements Runnable {  private SimpleDateFormat dateFormat;  private Date date;  public Thread1(SimpleDateFormat dateFormat, Date date) {    this.dateFormat = dateFormat;    this.date = date;  }  public void run() {    for (;;) {// 一直循环到出问题为止吧。      String strDate = dateFormat.format(date);      // 如果不等于2011-10-24，证明出现线程安全问题了！！！！      if (!"2011-10-24".equals(strDate)) {        System.err.println("today=" + strDate);        System.exit(0);      }    }  }}class Thread2 implements Runnable {  private SimpleDateFormat dateFormat;  private Date date;  public Thread2(SimpleDateFormat dateFormat, Date date) {    this.dateFormat = dateFormat;    this.date = date;  }  public void run() {    for (;;) {      String strDate = dateFormat.format(date);      // 如果不等于2011-10-25，证明出现线程安全问题了！！！！      if (!"2011-10-25".equals(strDate)) {        System.err.println("tomorrow=" + strDate);        System.exit(0);      }    }  }}

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转载?
http://www.cnblogs.com/hyddd/articles/1643978.html

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