抛出日期字符串的多个异常抛出

Question

我试图将一个字符串解析为一个对象的构造函数中的日期,我们将调用它Example.这是代码

private static final SimpleDateFormat sdf = new SimpleDateFormat(
        "yyyy-MM-dd HH:mm:ss");

private long time;

public Example(String date) {
    try {
        this.time = sdf.parse(date).getTime();
    } catch (Exception e) {
        logger.log(Level.WARNING, "Exception while parsing date " + date, e);
    }
}

现在,我在Tomcat实例中创建这些对象(无论是否有所不同).

我得到以下类型的例外

Fri Jul 06 15:13:48 EDT 2012 WARNING: Exception while parsing date 2012-07-06 18:57:31
java.lang.NumberFormatException: For input string: ""
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
    at java.lang.Long.parseLong(Long.java:431)
    at java.lang.Long.parseLong(Long.java:468)
    at java.text.DigitList.getLong(DigitList.java:177)
    at java.text.DecimalFormat.parse(DecimalFormat.java:1297)
    at java.text.SimpleDateFormat.subParse(SimpleDateFormat.java:1589)
    at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1311)
    at java.text.DateFormat.parse(DateFormat.java:335)
    at ...
Fri Jul 06 15:13:48 EDT 2012 WARNING: Exception while parsing date 2012-07-06 19:00:07
java.lang.NumberFormatException: multiple points
    at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1082)
    at java.lang.Double.parseDouble(Double.java:510)
    at java.text.DigitList.getDouble(DigitList.java:151)
    at java.text.DecimalFormat.parse(DecimalFormat.java:1302)
    at java.text.SimpleDateFormat.subParse(SimpleDateFormat.java:1934)
    at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1311)
    at java.text.DateFormat.parse(DateFormat.java:335)
    at ...
Fri Jul 06 15:13:48 EDT 2012 WARNING: Exception while parsing date 2012-07-06 19:13:21
java.lang.ArrayIndexOutOfBoundsException: -1
    at java.text.DigitList.fitsIntoLong(DigitList.java:212)
    at java.text.DecimalFormat.parse(DecimalFormat.java:1295)
    at java.text.SimpleDateFormat.subParse(SimpleDateFormat.java:1934)
    at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1311)
    at java.text.DateFormat.parse(DateFormat.java:335)
    at ...
Fri Jul 06 15:48:06 EDT 2012 WARNING: Exception while parsing last check string 2012-07-06 19:08:08
java.lang.NumberFormatException: For input string: ".200172E4.200172"
    at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1222)
    at java.lang.Double.parseDouble(Double.java:510)
    at java.text.DigitList.getDouble(DigitList.java:151)
    at java.text.DecimalFormat.parse(DecimalFormat.java:1302)
    at java.text.SimpleDateFormat.subParse(SimpleDateFormat.java:1589)
    at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1311)
    at java.text.DateFormat.parse(DateFormat.java:335)
    at ...

因此,日期失败了

2012-07-06 18:57:31
2012-07-06 19:00:07
2012-07-06 19:13:21
2012-07-06 19:08:08

但是,如果我进行单元测试,我会time从这些字符串中获取以下值

1341615451000
1341615607000
1341616401000
1341616088000

所以该SimpleDateFormat对象确实有效......但不在服务器上？我注意到这个问题发生在服务器启动附近,然后不再发生,如果这有帮助的话.不确定接下来该做什么.

使用Tomcat 7.0和Java 1.6更新32.

Answer 1

SimpleDateFormat不是线程安全的,如https://www.palantir.com/2007/07/simpledateformat-is-not-thread-safe/所述. 有时,使用"静态"对象时真正奇怪或非逻辑的行为来自并发问题

要解决这种情况,每次都要使用一个新实例(它比同步更好,因为同步会引发瓶颈问题)

Answer 2

SimpleDateFormat 不是线程安全的：请参阅 Javadoc。