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我无法通过从XML元素(我正在编写一个android应用程序)中解析字符串到日历对象,因此我可以计算字符串中的时间与当前时间之间的时间长度。我是全新的java来自.NET世界,所以在这里任何额外的背景可以真正有帮助。在Java中将字符串解析为日历?
我想使用的代码是:
// Using this class to define the format for date parsing.
SimpleDateFormat sdf = new SimpleDateFormat("yyyymmdd HH:mm:ss", Locale.ENGLISH);
// readArrivalValue reads the element from XML, which seems to be working.
String prdt = readArrivalValue(parser, "prdt");
// At this point prdt evaluates to the correct value: "20150331 20:14:40"
Date datePRDT = sdf.parse(prdt);
// datePRDT doesn't seem to be set properly. It evaluates to:
// datePRDT = {[email protected]}"Sat Jan 31 20:14:40 CST 2015"
// milliseconds = 1422761216000
// element.prdt is of type Calendar. Nothing is done to this prior to this statement.
element.prdt.setTime(datePRDT); // This throws a null pointer exception
是什么'element.prdt'? – 2015-04-01 02:39:08
对不起,应该指定 - 日历。我将编辑帖子。现在我意识到我可能必须以某种方式初始化它,因为它可能是一个引用类型? – tarun713 2015-04-01 02:40:01
我猜datePRDT不会导致NPE,但'element'或'element.prdt'对象造成它。确保你初始化它们 – 2015-04-01 02:42:27