What is NullPointerException in hive?
What is NullPointerException in hive?
If you get this NullPointer exception when joining two tables in hadoop hive, the problem may be that in one of the two tables the join key value is “” (blank string). For example, if you’re running this query: select users.id, locations. address from users left outer join locations on users.
What is NullPointerException in processing?
NullPointerException is thrown when a reference variable is accessed (or de-referenced) and is not pointing to any object. This error can be resolved by using a try-catch block or an if-else condition to check if a reference variable is null before dereferencing it.
What happens when you call a method on a null object?
One of the most common unchecked exceptions is the NullPointerException. It is thrown whenever an application attempts to use an object reference that has a null value. If you call a static method on an object with a null reference, you won’t get an exception and the code will run.
Is it good practice to catch NullPointerException?
It is generally a bad practice to catch NullPointerException. The program explicitly throws a NullPointerException to signal an error condition. The code is part of a test harness that supplies unexpected input to the classes under test.
How do you know if a long is null?
A primitive variable needs to be initialized to some value explicitly (e.g. to 0 ) so its value will never be null. If it is Long object then You can use longValue == null or you can use Objects. isNull(longValue) method in Java 7+ projects . Please check Objects for more info.
Can you call Main null?
Welcome to GeeksforGeeks!! Explanation: This program looks as though it is ought to throw a NullPointerException. However, the main method invokes the greet method (fun) on the constant null, and you can’t invoke a method on null.
Can we access static method using null reference?
If you call a static method on an object with a null reference, you won’t get an exception and the code will run. This is admittedly very misleading when reading someone else’s code, and it is best practice to always use the class name when calling a static method.
