java-collections-api

I have a method which generates an object each time I execute it, and I need to reverse the order with which I am getting them. So I thought the natural way to do it would be a Stack, since it is LIFO. However, the Java Stack does not seem to play well with the new Java 8 streaming API. If I do this: Stack<String> stack = new Stack<String>(); stack.push("A"); stack.push("B"); stack.push("C"); List<String> list = stack.stream().collect(Collectors.toList()); System.out.println("Collected: " + list); The output I get is: Collected: [A, B, C] Why isn't it outputing them in the expected LIFO order

the api of contains() method says "Returns true if this list contains the specified element. More formally, returns true if and only if this list contains at least one element e such that (o==null ? e==null : o.equals(e)). " I overrode the equals() method in my class but contains() still returns me false when i check my code class Animal implements Comparable<Animal>{ int legs; Animal(int legs){this.legs=legs;} public int compareTo(Animal otherAnimal){ return this.legs-otherAnimal.legs; } public String toString(){return this.getClass().getName();} public boolean equals(Animal otherAnimal){

I want to sort my ArrayList using a boolean type. Basically i want to show entries with true first. Here is my code below: Abc.java public class Abc { int id; bool isClickable; Abc(int i, boolean isCl){ this.id = i; this.isClickable = iCl; } } Main.java List<Abc> abc = new ArrayList<Abc>(); //add entries here //now sort them Collections.sort(abc, new Comparator<Abc>(){ @Override public int compare(Abc abc1, Abc abc2){ boolean b1 = abc1.isClickable; boolean b2 = abc2.isClickable; if (b1 == !b2){ return 1; } if (!b1 == b2){ return -1; } return 0; } }); Order before sorting: true true true false