In the previous tutorial, I introduced with you all about the Optional object in Java. In this tutorial, let’s find out some ways to initialize your Optional object in Java. OK … First, we can initialize an Optional object with the nulled reference variable. For… Read More
Assume, you are installing multiple Java versions in macOS, so how do you change from one version to another? In this tutorial, I will guide you to do this. First, let’s open Terminal and enter the following command to check all the Java versions that… Read More
In Java 8, the iterate() method has been introduced and it has only two parameters and will help us to create an infinite stream. Content:
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public static<T> Stream<T> iterate(final T seed, final UnaryOperator<T> f) |
Example:
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package com.huongdanjava.javastream; import java.util.stream.Stream; public class Example { public static void main(String[] args) { Stream.iterate(1, i -> i + 1).forEach(System.out::println); } } |
When running the above example, you will see that a Stream object contains endless numbers beginning at… Read More
This method was added from Java 9.
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static<T> Stream<T> ofNullable(T t) |
This method will return the Stream object of an element in case this element is not null; if it is null, it returns an empty Stream. Example:
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package com.huongdanjava.javaexample; import java.util.stream.Stream; public class Example { public static void main(String[] args) { String s = null; Stream.ofNullable(s).forEach(System.out::println); } } |
When you run the above code, it will print… Read More
This method was added from Java 9.
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default Stream<T> dropWhile(Predicate<? super T> predicate) |
This method also has the parameter Predicate interface and its function is the opposite of the takeWhile() method. This method also passes each element in your Stream object from left to right and ignores all elements that… Read More
This method was added from Java 9.
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default Stream<T> takeWhile(Predicate<? super T> predicate) |
The parameter of this method is the Predicate interface and this method takes the elements in your Stream object from left to right, until the condition of the Predicate object is no longer fulfilled. Example:
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package com.huongdanjava.javastream; import java.util.stream.Stream; public class Example { public static void main(String[] args) { Stream.of(1,2,3,4,5,6,7,8,9,10) .takeWhile(i -> i < 5) .forEach(System.out::println); } } |
In… Read More
Multithreading is the notion of handling program actions that do not take place in the program’s main Thread, which is handled by many different Threads. This concept will make the processing of the program faster. We have many ways to implement multithreading in Java, but… Read More
Reactive Streams are a concept that defines the mechanism for handling streams asynchronously with non-blocking back pressure. Back pressure here, we can understand that there is too much work to do at the same time, then it should lead to overload. Non-blocking back pressure means… Read More
If you have ever worked with some languages like Python, Scala, you may know we can write code and execute code for those languages using only the command line. This will allow us to test some code without having to do a lot of things,… Read More
In the previous tutorial about NullPointerException in Java, I have presented to you some cases where NPE can occur and how to deal with them to avoid. From Java 8, we have another way to avoid NullPointerException, that will use the Optional object. What is… Read More
