//: com/mindviewinc/util/CountingMapData.java // ©2015 MindView LLC: see Copyright.txt // Unlimited-length Map containing sample data. package com.mindviewinc.util; import java.util.*; public class CountingMapData extends AbstractMap { private int size; private static String[] chars = "A B C D E F G H I J K L M N O P Q R S T U V W X Y Z" .split(" "); public CountingMapData(int size) { if(size < 0) this.size = 0; else this.size = size; } private static class Entry implements Map.Entry { int index; Entry(int index) { this.index = index; } @Override public boolean equals(Object o) { return Integer.valueOf(index).equals(o); } @Override public Integer getKey() { return index; } @Override public String getValue() { return chars[index % chars.length] + Integer.toString(index / chars.length); } @Override public String setValue(String value) { throw new UnsupportedOperationException(); } @Override public int hashCode() { return Integer.valueOf(index).hashCode(); } } @Override public Set> entrySet() { // LinkedHashSet retains initialization order: Set> entries = new LinkedHashSet<>(); for(int i = 0; i < size; i++) entries.add(new Entry(i)); return entries; } public static void main(String[] args) { System.out.println(new CountingMapData(60)); } } /* Output: {0=A0, 1=B0, 2=C0, 3=D0, 4=E0, 5=F0, 6=G0, 7=H0, 8=I0, 9=J0, 10=K0, 11=L0, 12=M0, 13=N0, 14=O0, 15=P0, 16=Q0, 17=R0, 18=S0, 19=T0, 20=U0, 21=V0, 22=W0, 23=X0, 24=Y0, 25=Z0, 26=A1, 27=B1, 28=C1, 29=D1, 30=E1, 31=F1, 32=G1, 33=H1, 34=I1, 35=J1, 36=K1, 37=L1, 38=M1, 39=N1, 40=O1, 41=P1, 42=Q1, 43=R1, 44=S1, 45=T1, 46=U1, 47=V1, 48=W1, 49=X1, 50=Y1, 51=Z1, 52=A2, 53=B2, 54=C2, 55=D2, 56=E2, 57=F2, 58=G2, 59=H2} *///:~