Java 8 : Iterating Collections. Creating stream, Generating Stream, Obtaining Stream

        Iterations

	package com.tvidushi.java8.iterate;
	import java.util.Arrays;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.stream.Stream;
	/**
	*
	* @author takshila.vidushi
	*
	*/
	public class IterationExamples {
	/**
	* Obtaining a stream from (LIST)
	*/
	public static void iterationgList(){
	System.out.println("---Obtaining a stream from (LIST)---");
	populateList().stream()
	.forEach((x)->System.out.print(" "+x));
	}
	/**
	* Obtaining a stream from (MAP USING ENTRYSET)
	*/
	public static void iterationgMap(){
	System.out.println("---Obtaining a stream from (MAP USING ENTRYSET)---");
	populateMap().entrySet()
	.stream()
	.forEach(x->System.out.println(x));;
	}
	/**
	* Obtaining a stream from (MAP USING ENTRYSET)
	*/
	public static void iterationgMap2(){
	Map<String,String> map = populateMap();
	for(Map.Entry<String, String> entry: map.entrySet()){
	System.out.println("map name is :"+entry.getKey()+"map entry is :"+entry.getValue());
	}
	}
	/**
	* Obtaining a stream from (MAP USING KEYSET)
	*/
	public static void iterationgMap3(){
	System.out.println("--Obtaining a stream from (MAP USING KEYSET)----");
	populateMap().keySet()
	.stream()
	.forEach(x->System.out.println(" "+x));
	}
	/**
	* Obtaining a stream from (MAP USING VALUES)
	*/
	public static void iterationgMap4(){
	System.out.println("----Obtaining a stream from (MAP USING VALUES)-----");
	populateMap().values()
	.stream()
	.forEach(x->System.out.print(" "+x));
	}
	/**
	* Obtaining a stream from (STRING USING CHARS)
	*/
	public static void iterationgChars(){
	System.out.println("--Obtaining a stream from (STRING USING CHARS)-----");
	"123456789sadasdas".chars().forEach(x->System.out.print(" "+(char)x));
	}
	/**
	* Obtaining a stream from (STRING USING SPLIT)
	*/
	public static void iterationgString(){
	System.out.println("--Obtaining a stream from (STRING USING SPLIT)--");
	Stream.of(("hot summer cool winter ".split(" ")))
	.forEach(x->System.out.print(" "+x));
	}
	/**
	* Obtaining a stream from (FROM AN ARRAY)
	*/
	public static void iterationgArrays(){
	System.out.println("-----------Obtaining a stream from (FROM AN ARRAY)--");
	Integer[] array = {1,2,3,4,5,6,7,8,9,10};
	Stream.of(array).forEach(x->System.out.print(" "+x));
	}
	/**
	* Obtaining a stream from (OF VALUES)
	*/
	public static void createStream(){
	System.out.println("-----------Obtaining a stream from (OF VALUES)--");
	Stream.of("one","two","three").forEach(x->System.out.println(x));
	}
	/**
	* Obtaining a stream from (FROM FUNCTION GENERATE)
	*/
	public static void generatingStream(){
	System.out.println("-----------Obtaining a stream from (FROM FUNCTION GENERATE)---------");
	Stream.generate(()->{return Math.random();})
	.limit(20)
	.forEach(x->System.out.println(x));
	}
	/**
	* Obtaining a stream from (FROM FUNCTION ITERATE)
	*/
	public static void obtainStream(){
	System.out.println("-----------Obtaining a stream from (FROM FUNCTION ITERATE)------------");
	Stream.iterate(0,i->i+1)
	.limit(30)
	.forEach(x->System.out.println(x));
	}
	/**
	* Obtaining a stream from (FROM FUNCTION BUILDER)
	*/
	public static void createStream_Builderfn(){
	System.out.println("-----------Obtaining a stream from (FROM FUNCTION BUILDER)-------");
	Stream.builder()
	.add("one")
	.add("two")
	.add("three")
	.build()
	.forEach(p->System.out.println(p));
	}
	/**
	* Obtaining a stream from (ANOTHER STREAM)
	*/
	public static void createStream_2(){
	System.out.println("-----------Obtaining a stream from (ANOTHER STREAM)----------------");
	populateList().stream()
	.distinct()
	.limit(2)
	.sorted()
	.forEach(x->System.out.println(x));
	}
	public static void main(String args[]){
	iterationgList();
	System.out.println();
	iterationgMap();
	System.out.println();
	iterationgMap2();
	System.out.println();
	iterationgMap3();
	System.out.println();
	iterationgMap4();
	System.out.println();
	iterationgChars();
	System.out.println();
	iterationgString();
	System.out.println();
	iterationgArrays();
	System.out.println();
	createStream_Builderfn();
	System.out.println();
	createStream_2();
	}
	private static List<String> populateList(){
	return Arrays.asList("value1","value2","value3","value4","value5","value6","value6","value7","value8","value9","value10");
	}
	private static Map populateMap(){
	Map<String,String> map = new HashMap();
	map.put("mapKey1", "mapValue1");
	map.put("mapKey2", "mapValue2");
	map.put("mapKey3", "mapValue3");
	map.put("mapKey4", "mapValue4");
	map.put("mapKey5", "mapValue5");
	map.put("mapKey6", "mapValue6");
	return map ;
	}
	}

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Output: