由此可见在判断Map或者List是否包含一个值时,就算这个值是null,也不会引起报错。
System.NullPointerException: Attempt to de-reference a null object is very common error in apex class. It occurs when your variable (sobject, list, set or any other data type) is not initialized (allocated memory). In order to use the non primitive data type in the code we need to in...
我正在使用scriptler jenkins插件执行简单的groovy脚本。hudson.model.Computer如果我在主设备或任何从设备上执行此命令,则会给出NullPointerException java.lang.NullPointerException: Cannot invoke method getNodeName() onn 浏览5提问于2015-04-24得票数 1 ...
Check TextInputEditText in AlertDialog in android, I wrote this code to set a password in AlertDialog but when I click on the button to save the password, it does not check TextInputEditText and the dialog is closed. What should I do? (my dialog run in first activity) public class Creat...
java.io.FileNotFoundException:打开失败: EISDIR (是一个目录) 、 在搜索了关于如何将文件保存为不推荐的getExternalPublicDirectory的答案之后,我使用了context.getExternalFilesDir(null).getAbsolutePathprivate void startRecording() throws IOException { String path =context.getExternalFilesDir(null).getAbsolutePath(...