nullpointerexception

问题 I'm creating an Android application. The problem is that when I press the button and pass the data to the new array, it goes to black and giving me this error: Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.util.ArrayList.add (java.lang.Object) 'on a null object reference By debugging, it gives me something in the string: mExampleList.add(Ticket) My ExampleAdapter class: public class ExampleAdapter extends RecyclerView.Adapter<ExampleAdapter

问题 I'm creating an Android application. The problem is that when I press the button and pass the data to the new array, it goes to black and giving me this error: Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.util.ArrayList.add (java.lang.Object) 'on a null object reference By debugging, it gives me something in the string: mExampleList.add(Ticket) My ExampleAdapter class: public class ExampleAdapter extends RecyclerView.Adapter<ExampleAdapter

问题 Upgrading Java from 7u161 to 7u171 prevents JBoss AS 7.1.1.Final from starting. I know JBoss AS 7.1.1 is EOL but for compatibility reasons, we still need to run this version. Very early in the startup, a NullPointerException occurs in some JBoss method. Following is the exception: Exception in thread "main" javax.xml.parsers.FactoryConfigurationError: Provider __redirected.__SAXParserFactory could not be instantiated: java.lang.NullPointerException [...] Caused by: java.lang

问题 Upgrading Java from 7u161 to 7u171 prevents JBoss AS 7.1.1.Final from starting. I know JBoss AS 7.1.1 is EOL but for compatibility reasons, we still need to run this version. Very early in the startup, a NullPointerException occurs in some JBoss method. Following is the exception: Exception in thread "main" javax.xml.parsers.FactoryConfigurationError: Provider __redirected.__SAXParserFactory could not be instantiated: java.lang.NullPointerException [...] Caused by: java.lang

问题 Somehow, I cannot add items to my ComboBox variable from another class as it always says either the value of variable is null or the return value of its getter is null. I use Scene Builder to build Sample.fxml, with controller as Controller class, luanch the whole thing form UserInterface class FXML <?xml version="1.0" encoding="UTF-8"?> <?import javafx.scene.control.ComboBox?> <?import javafx.scene.layout.BorderPane?> <BorderPane xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http:/

问题 Somehow, I cannot add items to my ComboBox variable from another class as it always says either the value of variable is null or the return value of its getter is null. I use Scene Builder to build Sample.fxml, with controller as Controller class, luanch the whole thing form UserInterface class FXML <?xml version="1.0" encoding="UTF-8"?> <?import javafx.scene.control.ComboBox?> <?import javafx.scene.layout.BorderPane?> <BorderPane xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http:/

问题 I am working on an android project and as far as I know, I don't make any specific mistakes in my code that would lead to an exception. I get these two error lines everytime I run my project, but the rest of my code runs without any issues. The NullPointerException doesn't have a concrete occurance location , which confuses me. I have already searched for similar issues. A possible solution was adding the READ_EXTERNAL_STORAGE and WRITE_EXTERNAL_STORAGE as uses-permission in my Android

问题 I am working on an android project and as far as I know, I don't make any specific mistakes in my code that would lead to an exception. I get these two error lines everytime I run my project, but the rest of my code runs without any issues. The NullPointerException doesn't have a concrete occurance location , which confuses me. I have already searched for similar issues. A possible solution was adding the READ_EXTERNAL_STORAGE and WRITE_EXTERNAL_STORAGE as uses-permission in my Android

来源： https://stackoverflow.com/questions/46098859/return-null-from-fun-in-kotlin

来源： https://stackoverflow.com/questions/51469394/null-pointer-exception-reading-h2o-mojo-zip