Initialize a static Map using Stream in Java
Last Updated :
29 Oct, 2021
In this article, a static map is created and initialized in Java using Stream.
Static Map in Java
A static map is a map which is defined as static. It means that the map becomes a class member and can be easily used using class.
Stream In Java
Introduced in Java 8, the Stream API is used to process collections of objects. A stream is a sequence of objects that supports various methods which can be pipelined to produce the desired result.
Approach:
- Create a stream and insert 2D values as Key and Value pair in it.
- These values will be later used to instantiate the Map.
- Using the collect() method of Stream, map the values from the stream to the map.
- This can be done with the help of Collectors.toMap() method and the keyMapper and ValueMapper respectively.
Below is the implementation of the above approach:
import java.util.*;
import java.util.stream.Collectors;
class GFG {
private static Map<String, String> map
= Arrays.stream( new String[][] {
{ "1" , "GFG" },
{ "2" , "Geek" },
{ "3" , "GeeksForGeeks" } })
.collect(Collectors.toMap(
keyMapper -> keyMapper[ 0 ], valueMapper -> valueMapper[ 1 ]));
public static void main(String[] args)
{
System.out.println(map);
}
}
|
Output:
{1=GFG, 2=Geek, 3=GeeksForGeeks}
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