Top "Nullpointerexception" questions

Hibernate query.list() method is returning empty list instead of null value

When there are no rows, both query.list() and criteria.list() are returning empty list instead of a null value. …

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How to handle nulls when using Java collection sort

When using Collection.sort in Java what should I return when one of the inner objects is null Example: Collections.…

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Best explanation for languages without null

Every so often when programmers are complaining about null errors/exceptions someone asks what we do without null. I have …

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getApplicationContext() on a null object reference

I allways get this java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.content.Context.getApplicationContext()' …

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What is dereferencing possible null pointer?

I am making a program for SFTP in NetBeans. Some part of My code: com.jcraft.jsch.Session sessionTarget = null; …

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Attempt to invoke virtual method 'void android.support.v4.view.ViewPager.setAdapter(android.support.v4.view.PagerAdapter)' on a null object reference

I'm trying to implement sliding tab layout using android material design. But it gives me NullPointerException. Here is my code …

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Why do Double.parseDouble(null) and Integer.parseInt(null) throw different exceptions?

Why do Double.parseDouble(null) and Integer.parseInt(null) throw different exceptions? Is this a historical accident or intentional? The …

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Unboxing Null-Object to primitive type results in NullPointerException, fine?

This snippet throws an NullPointerException due to the fact that its unboxed to a primitive type and Long.longValue() is …

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javax.xml.parsers.FactoryConfigurationError running JBoss AS 7.1 with Java 7 update 171

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 …

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NullPointerExcetion Native Method Accessor... Hashing Words Issue

I am writing a project that reads a file and sorts "Words". This code compiles correctly, yet then it gives …

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