• Use queue from chapter 3
• Supply an iterator (with do-nothing remove method)
• add method always returns true

 file:horstmann/ch08_queue/BoundedQueue.java [source] [doc-public] [doc-private]
 ``` 001 002 003 004 005 006 007 008 009 010 011 012 013 014 015 016 017 018 019 020 021 022 023 024 025 026 027 028 029 030 031 032 033 034 035 036 037 038 039 040 041 042 043 044 045 046 047 048 049 050 051 052 053 054 055 056 057 058 059 060 061 062 063 064 065 066 067 068 069 070 071 072 073 074 075 076 077 078 079 080 081 082 083 084 085 086 087 088 089 090 091 092 093 094 095 096 097 098 099 100 101 102 103 104 105 106 107 ``` ```package horstmann.ch08_queue; import java.util.AbstractCollection; import java.util.ArrayList; import java.util.Iterator; /** A first-in, first-out bounded collection of objects. */ public class BoundedQueue extends AbstractCollection { /** Constructs an empty queue. @param capacity the maximum capacity of the queue

Precondition: capacity > 0

*/ public BoundedQueue(int capacity) { elements = new ArrayList(capacity); count = 0; head = 0; tail = 0; } public Iterator iterator() { return new Iterator() { public boolean hasNext() { return visited < count; } public E next() { int index = (head + visited) % elements.size(); E r = elements.get(index); visited++; return r; } public void remove() { throw new UnsupportedOperationException(); } private int visited = 0; }; } /** Remove object at head. @return the object that has been removed from the queue

Precondition: size() > 0

*/ public E remove() { E r = elements.get(head); head = (head + 1) % elements.size(); count--; return r; } /** Append an object at tail. @param anObject the object to be appended @return true since this operation modifies the queue. (This is a requirement of the collections framework.)

Precondition: !isFull()

*/ public boolean add(E anObject) { elements.set(tail,anObject); tail = (tail + 1) % elements.size(); count++; return true; } public int size() { return count; } /** Checks whether this queue is full. @return true if the queue is full */ public boolean isFull() { return count == elements.size(); } /** Gets object at head. @return the object that is at the head of the queue

Precondition: size() > 0

*/ public E peek() { return elements.get(head); } private ArrayList elements; private int head; private int tail; private int count; } ```

 file:horstmann/ch08_queue/QueueTester.java [source] [doc-public] [doc-private]
 ``` 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 ``` ```package horstmann.ch08_queue; import java.util.ArrayList; import java.util.Collections; public class QueueTester { public static void main(String[] args) { BoundedQueue q = new BoundedQueue(10); q.add("Belgium"); q.add("Italy"); q.add("France"); q.remove(); q.add("Thailand"); ArrayList a = new ArrayList(); a.addAll(q); System.out.println("Result of bulk add: " + a); System.out.println("Minimum: " + Collections.min(q)); } } ```