How to Reduce the Size of the Stream with the Limit Method in Java 8
See Java: Tips and Tricks for similar articles.The limit method of the Stream
class introduced in Java 8 allows the developer to limit the number of elements that will be extracted from a stream. The limit method is useful in those applications where the user wishes to process only the initial elements that occur in the stream. To learn how to reduce the size of the stream with the limit method, follow these five steps.
- Open your text editor and create the Java program that will create the stream and apply the limit method. Type in the following Java statements:
The stream will be created from the ArrayList that is defined on line 4. Note that a static block is used to add elements to the ArrayList. A static block is executed one time when the program is loaded into memory. The user is asked how many persons are to be displayed on the console. The result entered by the user is checked to see if it is greater than the number of elements in the ArrayList. If this is the case, then the result is equated to the number of elements in the list. The ArrayList is then converted to a stream and the limit method is applied using the number entered by the user. I have highlighted the limit method in the image below:
import java.util.stream.*; import java.util.*; import java.io.*; public class ReduceStreamSizeWithlimitMethod { private static List
names=new ArrayList<>(); static { names.add("Stephen"); names.add("Regina"); names.add("Edward"); names.add("Miguel"); names.add("George"); names.add("Brad"); } public static void main (String args[]) { Console console=System.console(); int userLimit=Integer.parseInt(console.readLine("Please enter the number of persons you wish to display: ")); // if the user enters a number greater than the list size then set number equal to size if (userLimit > names.size()) { userLimit=names.size(); } names.stream().limit(userLimit).forEach(System.out::println); } } - Save your file as
ReduceStreamSizeWithlimitMethod.java
. - Open a command prompt and navigate to the directory containing your new Java program. Then type in the command to compile the source and hit Enter.
- You are ready to test your Java program. Type in the command to run the Java runtime launcher and hit Enter. When prompted for the limit, type "3" as shown below. The output displays the first three names because the limit method was applied to the stream using the number you entered.
- Test your program again using a limit greater than the size of the ArrayList, which is 6. Type in the command to run the Java runtime launcher and hit Enter. When prompted for the limit, type "7" as shown below. The output now displays all of the names because the limit method was applied to the stream using the size of the ArrayList as the limit number.
Related Articles
- How to Check Object Type in Java
- How to Create a Jar File in Java
- How to Compile Packages in Java
- How to Throw an Exception in Java
- How to Create an Exception Class in Java
- How to Use the super Keyword to Call a Base Class Constructor in Java
- How to Use the Comparator.comparing Method in Java 8
- How to Use System.in in Java
- How to Call an Interface Method in Java
- How to Add a Time Zone in the Java 8 Date/Time API
- How to Rethrow an Exception in Java
- How to Use the instanceof Operator with a Generic Class in Java
- How to Instantiate an Object in Java
- How to Filter Distinct Elements from a Collection in Java 8
- How to Create a Derived Class in Java
- How to Skip Elements with the Skip Method in Java 8
- How to Create a Java Bean
- How to Implement an Interface in Java
- How to Compare Two Objects with the equals Method in Java
- How to Set PATH from JAVA_HOME
- How to Prevent Race Conditions in Java 8
- How to Write a Block of Code in Java
- How to Display the Contents of a Directory in Java
- How to Group and Partition Collectors in Java 8
- How to Create a Reference to an Object in Java
- How to Reduce the Size of the Stream with the Limit Method in Java 8 (this article)
- How to Write an Arithmetic Expression in Java
- How to Format Date and Time in the Java 8 Date/Time API
- How to Use Comparable and Comparator in Java
- How to Break a Loop in Java
- How to Use the this Keyword to Call Another Constructor in Java
- How to Write a Unit Test in Java
- How to Declare Variables in Java
- How to Override Base Class Methods with Derived Class Methods in Java
- How to Use Serialized Objects in Java
- How to Write Comments in Java
- How to Implement Functional Interfaces in Java 8
- How to Write Type Parameters with Multiple Bounds in Java
- How to Add Type and Repeating Annotations to Code in Java 8
- How to Use Basic Generics Syntax in Java
- How to Map Elements Using the Map Method in Java 8
- How to Work with Properties in Java
- How to Write while and do while Loops in Java
- How to Use the finally Block in Java
- How to Write for-each Loops in Java
- How to Create a Method in Java
- How to Continue a Loop in Java
- How to Handle Java Files with Streams
- How to Create an Interface Definition in Java
- How Default Base Class Constructors Are Used with Inheritance