Java Array to Set

In this post, we will learn java array to set conversion.

Table of Contents

1. Using Java 8’s Stream
2. Using HashSet constructor()
3. Using Google Guava()

There are many ways to convert array to set.

1. Using Java 8’s Stream

If you are using Java 8, I would recommend using this method.

package org.arpit.java2blog;

import java.util.Arrays;

import java.util.Set;

import java.util.stream.Collectors;

public class ArrayToSetMain {

public static void main(String[] args) {

String s[]= {"John","Martin","Mary","John","Martin"};

Set<String> set = Arrays.stream(s).collect(Collectors.toSet());

System.out.println(set);

}

Output

[John, Martin, Mary]

2. Using HashSet constructor()

We can directly call HashSet‘s constructor for java set to array conversion.

package org.arpit.java2blog;

import java.util.Arrays;

import java.util.HashSet;

import java.util.Set;

public class ArrayToSetMain {

public static void main(String[] args) {

String s[]= {"John","Martin","Mary","John","Martin"};

Set<String> set = new HashSet<>(Arrays.asList(s));;

System.out.println(set);

}

Output

[John, Martin, Mary]

3. Using Google Guava()

We can use google guava library to do Array to Set conversion using Sets’s newHashSet method.

package org.arpit.java2blog;

import java.util.Arrays;

import java.util.HashSet;

import java.util.Set;

import org.apache.commons.compress.utils.Sets;

public class ArrayToSetMain {

public static void main(String[] args) {

String s[]= {"John","Martin","Mary","John","Martin"};

Set<String> set = Sets.newHashSet(s);

System.out.println(set);

}

Output

[John, Martin, Mary]

That’s all about Java Array to set conversion.

Initialize ArrayList with values in Java

Collections in java

Author

Conversion Java 8 Java Date

12 January

In this post, we will see how to convert Date to LocalDate in java. Sometimes, we may need to convert Date to new Java 8 APIs and vice versa. There are multiple ways to convert Date to LocalDate in java. Read also: Convert LocalDate to Date in java Using toInstant() method of Date class You […]

Conversion Java 8 Java Date

11 January

Java LocalDate to Date

In this post, we will see how to convert LocalDate to Date. Java 8 has introduced a lot of new APIs for Date and time. There can be many ways to convert Java LocalDateTime to date. Using Instant object You can convert LocalDate to Date using Instant object which we can from Zone. Here is […]

Conversion Java 8

18 November

Convert LocalDateTime to Timestamp in Java

In this post, we will how to convert LocalDateTime to Timestamp . Before learning how to convert localdatetime to timestamp, let us learn about LocalDateTime and Timestamp, and understand the importance of this conversion. LocalDateTime LocalDateTime was introcuded in Java 8. LocalDateTime can be imported time package: import java.time.LocalDateTime; LocalDateTime is an immutable object used […]

Conversion Java 8

26 April

Java Stream List to Map

In this post, we will see how to convert List to Map using Stream in java 8. Collectors’s toMap() can be used with Stream to convert List to Map in java. Consider a class Named Movie which have 3 fields – id, name and genre [crayon-600d6d9c6ec74604783640/] Create a list of movies and convert with to […]

Conversion String

29 February

Java long to String

In this post, we will see how to convert long to String in java. There are lot of ways to convert long to String.Let’s see each one by one. Using Long.toString() You can use Long class toString() method to convert long to String. [crayon-600d6d9c6f12a133828286/] In case, Long can be null and you don’t want to […]

Conversion Java 8

15 May

Java LocalDateTime to Date

In this post, we will see how to convert LocalDateTime to Date. Java 8 has introduced a lot of new APIs for Date and time. There can be many ways to convert Java LocalDateTime to date. Using Instant object You can convert LocalDateTime to date using Instant object which we can from ZonedDateTime. Here is […]

1. Using Java 8’s Stream

2. Using HashSet constructor()

3. Using Google Guava()

You may also like:

Initialize ArrayList with values in Java

PriorityQueue in Java 8

2d Arraylist java example

How HashMap works in java

How to Sort HashSet in Java

Java Array to Set

Java Set to Array

Java Collection to List

Java Collections shuffle

Collections in java

Author

Related Posts