https://stackoverflow.com › questions › 411447
java - How to show if a method may return null - Stack OverflowIt is almost always possible to design your code such that a null value is never returned from your APIs during "normal" flow of execution. (For example, check foo.contains(obj) rather then calling foo.get(obj) and having a separate branch for null. Or, use the Null object pattern.
https://stackoverflow.com › questions › 17302256
Best way to check for null values in Java? - Stack OverflowBefore calling a function of an object, I need to check if the object is null, to avoid throwing a NullPointerException. What is the best way to go about this? I've considered these methods. Which one is the best programming practice for Java? // Method 1 if (foo != null) { if (foo.bar()) { etc... } } // Method 2 if (foo != null ? foo.bar ...
https://www.baeldung.com › java-avoid-null-check
Avoid Check for Null Statement in Java - BaeldungLearn several strategies for avoiding the all-too-familiar boilerplate conditional statements to check for null values in Java.
https://www.baeldung.com › java-check-all-variables-object-null
Check If All the Variables of an Object Are Null | BaeldungIn this article, we’ve seen the importance of checking for null variables in our classes and how to do that using if statements, Streams, the Apache commons-lang3 library, and the Reflection API. As usual, the source code is available over on GitHub.
https://betterprogramming.pub › checking-for-nulls-in-java-minimize-using-if-else-edae...
Checking for Nulls in Java? Minimize Using “If Else”1. java.util.Optional. A container object which may or may not contain a non-null value. If a value is present, isPresent() will return true and get() will return the value.¹. One of the most common place Optional is used in the project that I am currently working on is while retrieving data from the database. Let's say that you have 3 things:
https://www.baeldung.com › java-notnull-method-parameter
Using @NotNull on a Method Parameter - BaeldungIn this article, we learned how to use the @NotNull annotation on a method parameter in a standard Java application. We also learned how to use Spring Boot’s @Validated annotation to simplify our Spring Bean method parameter validation while also noting its limitations.
https://docs.oracle.com › javase › 8 › docs › api › java › lang › NullPointerException.html
NullPointerException (Java Platform SE 8 ) - OracleThrown when an application attempts to use null in a case where an object is required. These include: Calling the instance method of a null object. Accessing or modifying the field of a null object. Taking the length of null as if it were an array. Accessing or modifying the slots of null as if it were an array.
https://medium.com › swlh › null-checking-done-right-with-optionals-78003c9329a7
Null-Checking Done Right with Optionals - MediumFortunately, you can reduce your null-checking boilerplate code using the Optional class for most of the cases. The Optional API was first introduced as part of the Java Development Kit 8, and...
https://docs.oracle.com › javase › 8 › docs › technotes › tools › windows › javadoc.html
javadoc - OracleThe javadoc command can be run three ways without explicitly specifying the source file names. You can pass in package names, use the -subpackages option, or use wild cards with source file names.
These utilities include null-safe or null-tolerant methods for computing the hash code of an object, returning a string for an object, comparing two objects, and checking if indexes or sub-range values are out of bounds.
