NullPointerException应该是 Java 开发中最常出现的问题,也是 Java 程序员最容易犯的错误。虽然看起来是个小错误,但带来的影响却不小,Tony Hoare(null 引用的发明者)在 2009 年说过 NPE 大约给企业造成数十亿美元的损失。在这工作半年内,我就踩了好几次 NPE 的坑。举个例子,我需要在原有逻辑上加一段代码,
Exceptionin thread"main"java.lang.NullPointerException:Cannot invoke"RegistryAddress.getCity()"because thereturnvalueof"com.developlee.java14.helpfulnullpointerexceptions.HelpfulNullPointerException$DetailInfos.getRegistryAddress()"isnull at com.developlee.java14.helpfulnullpointerexceptions.HelpfulNullPointer...
Integer i = null; int x = i; // runtime error 虽然当该代码运行时会报出NullPointerException的错误。 成员方法调用 null 是够糟糕的;当你从未见过该方法被调用时更糟糕。 6. NULL 难以调试 来解释 NULL 是多么的麻烦,C++ 是一个很好的例子。调用成员函数指向一个 NULL 指针不一定会导致程序崩溃。更糟...
问条目值为空的Collectors.toMap中的NullPointerExceptionEN我写了一个Collector，与默认的java不同，当你...
publicclassTest { publicString test ="abd"; publicvoidtest(){ System.out.println("test"); } publicstaticvoidmain(String[] args) { Test t =null; System.out.println(t.test); t.test(); } } 结果如下: Exception in thread"main"java.lang.NullPointerException ...
HTTP Status 500 -Request processing failed; nested exception is java.lang.NullPointerException type Exception report message Request processing failed; nested exception is java.lang.NullPointerException description The server encountered an internal error that prevented it from fulfillingthisrequest. ...
java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int, java.io.OutputStream)' on a null object reference 03-06 23:31:01.730 4515 4654 E AndroidRuntime: at com.mr.flutter.plugin.filepicker.FileUtils....
Version 1.82b: --- - NULL pointer in is_javascript() fixed. Version 1.81b: ---2 changes: 1 addition & 1 deletion 2 Makefile Original file line numberDiff line numberDiff line change @@ -20,7 +20,7 @@ # PROGNAME = skipfish VERSION = 1.81b VERSION = 1.82b OBJFILES = http_...
java.lang.NullPointerException: Expected timestamp in the Flume event headers, but it was null http://www.bkjia.com/xtzh/742208.html 使用flume的时候出现的问题。 hdfs.useLocalTimeStamp这个参数,比如以每个小时作为一个文件夹,那么配置应该是这样:...
But I get this error: NullReferenceException: Object reference not set to an instance of an object.at: ...foreach (CONISSubObject cSO in cRO.Properties)...Any hint why is that the case? Thanks.All replies (9)Monday, February 12, 2018 10:02 PM ✅Answered...