Joda Time - 计算两个日期之间的秒数会引发异常.

Question

我使用以下代码来计算两个日期之间的秒数差异:

long secondsBetween = (Seconds.secondsBetween(new LocalDate("1901-01-01"), new LocalDate()).getSeconds());

但是我得到以下异常:

08-08 18:21:27.345: E/AndroidRuntime(6972): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.testbdr/com.testbdr.MainActivity}: java.lang.ArithmeticException: Value cannot fit in an int: 3584908800
08-08 18:21:27.345: E/AndroidRuntime(6972):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2189)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2216)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at android.app.ActivityThread.access$600(ActivityThread.java:149)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1305)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at android.os.Looper.loop(Looper.java:153)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at android.app.ActivityThread.main(ActivityThread.java:5000)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at java.lang.reflect.Method.invokeNative(Native Method)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at java.lang.reflect.Method.invoke(Method.java:511)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:821)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:584)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at dalvik.system.NativeStart.main(Native Method)
08-08 18:21:27.345: E/AndroidRuntime(6972): Caused by: java.lang.ArithmeticException: Value cannot fit in an int: 3584908800
08-08 18:21:27.345: E/AndroidRuntime(6972):     at org.joda.time.field.FieldUtils.safeToInt(FieldUtils.java:206)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at org.joda.time.field.BaseDurationField.getDifference(BaseDurationField.java:141)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at org.joda.time.chrono.BaseChronology.get(BaseChronology.java:260)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at org.joda.time.base.BaseSingleFieldPeriod.between(BaseSingleFieldPeriod.java:105)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at org.joda.time.Seconds.secondsBetween(Seconds.java:124)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at com.testbdr.MainActivity.onCreate(MainActivity.java:27)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at android.app.Activity.performCreate(Activity.java:5020)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
08-08 18:21:27.345: E/AndroidRuntime(6972):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2153)
08-08 18:21:27.345: E/AndroidRuntime(6972):     ... 11 more

Answer 1

int

正如其他答案正确陈述,问题是你和Joda-Time正在使用一个int来处理秒.一个32位的int只能容纳大约68年的秒数.

如果您坚持使用秒来跟踪几个世纪的时间,则必须使用64位long而不是32位int.

顺便说一句,在Unix中使用32位int来跟踪时间的秒数表示现实世界的问题知道2038年的问题.

秒不用于长时间跨度

正如其他人所说,使用秒来跟踪如此长的时间跨度是不寻常的.如果可能的话,您可能想重新考虑这个前提.

一种替代方案:ISO 8601标准提供持续时间格式,PnYnMnDTnHnMnS包括年数,月数,天数等.Joda-Time知道如何解析并生成这样的字符串(Period和Duration类).虽然约达时间只能处理int 数字表示秒,当所呈现它可以处理更大的秒数串在该ISO 8601格式,如下所示在代码示例(PT3584908800S).

毫秒

Joda-Time 使用毫秒内部跟踪一个从纪元开始的计数.Joda-Time提供了以毫秒为单位访问long值的方法.

我通常建议你在几毫秒内完成日期工作.但在你的情况下,它是有道理的,根据需要转换为秒.

一天的开始

要计算毫秒数,我们需要使用DateTime而不是LocalDate.

养成调用方法withTimeAtStartOfDay获取当天第一时刻的习惯.这个时间通常00:00:00但不总是因为夏令时或其他异常.

时区

时区至关重要LocalDate.日期(和一天的第一时刻)由时区决定.巴黎的新日早些时候比蒙特利尔更新.

如果省略时区,将使用JVM的当前默认时区.通常更好地明确并指定所需的时区.我怀疑你的目的,使用UTC有意义.

持续时间

Joda-Time提供持续时间类来表示解开时间线(宇宙历史)的时间跨度.

示例代码

使用Joda-Time 2.4的示例代码.

DateTime history = new DateTime( "1901-01-01", DateTimeZone.UTC ).withTimeAtStartOfDay();  // Technically, the call to withTimeAtStartOfDay is not necessary here as Joda-Time defaults to that for parsing a date-only string. But the call is a good habit and makes clear out intention.
DateTime today = new DateTime( DateTimeZone.UTC ).withTimeAtStartOfDay();

Duration duration = new Duration( history, today );
long millis = duration.getMillis(); // Use a long, not an int.
long seconds = ( millis / 1000L ); // Use a long, not an int. Maybe use BigDecimal or BigInteger if you want rounding.

转储到控制台.

System.out.println( "history: " + history );
System.out.println( "today: " + today );
System.out.println( "duration: " + duration );
System.out.println( "millis: " + millis );
System.out.println( "seconds: " + seconds );

跑步时

history: 1901-01-01T00:00:00.000Z
today: 2014-08-08T00:00:00.000Z
duration: PT3584908800S
millis: 3584908800000
seconds: 3584908800

当走向另一个方向时,要么:

• 将long一些秒传递给静态方法Duration.standardSeconds.
• 将ISO 8601字符串传递给Duration的构造函数.