Java container in-depth study using the abstract class customization

Package Org.rui.collection3.map;import Java.util.abstractmap;import Java.util.abstractset;import Java.util.arraylist;import Java.util.hashmap;import Java.util.hashset;import Java.util.hashtable;import Java.util.iterator;import Java.util.linkedhashmap;import Java.util.linkedhashset;import java.util.LinkedList; Import java.util.list;import java.util.map;import java.util.set;import java.util.treemap;import java.util.TreeSet;/ * Set * Use abstract class * * @author Lenovo * */public class Countries{public static final string[][] DATA ={//africa{" A "," a "},{" B "," B "},{" C "," C "},{" D "," D "},{" E "," E "},{" F "," F "},{" G "," G "},{" H "," H "},{" I "," I "},{" J "," J "},{" K "," K "},{" L "," L "},{" M "," M "},{" n "," n "},{" O "," O "},{" P "," P "},{" Q "," Q "}};p rivate static class Fly Weightmap extends Abstractmap<string, string>{private Static class Entry implements Map.entry<string, String >{int index; Entry (int index) {this.index = index;} @Overridepublic String GetKey () {return DATA[INDEX][0];} @Overridepublic String GetValue () {return data[index][1];} @Overridepublic string SetValue (string value) {throw new Unsupportedoperationexception ();} public int hashcode () {return index;} public boolean equals (Object o) {return data[index][0].equals (o);}} Use Abstractset by implementing size & Iterator by implementing Dimensions & Iterato using Set abstract static class Enterset extends ABSTRACTSET&L T map.entry<string, string>>{private int size; The enterset (int size)//share section only stores its index instead of the actual health and value {if (Size < 0) {this.size = 0;} else if (Size > data.length) {this.size = Data.length;} else{this.size = size;}} @Overridepublic int size () {return size;} Private class Iter implements Iterator<map.entry<string, string>>{//each iterator has only one entry object private Entry Entry = new E Ntry ( -1); @Overridepublic boolean hasnext () {return entry.index < size-1;} @Overridepublic java.util.map.entry<string, string> next () {Entry.index++;return Entry;} @Overridepublic void Remove () {throw new unsupportedoperationexception();}} @Overridepublic iterator<java.util.map.entry<string, string>> Iterator () {return new Iter ();}} public static set<java.util.map.entry<string, string>> entries = new Enterset (data.length); Overridepublic set<java.util.map.entry<string, string>> EntrySet () {return entries;}} Create a partial map of size countries creates a part size country map static map<string, string> Select (final int size) {return new Flyweightmap () {@Overridepublic set<java.util.map.entry<string, string>> EntrySet () {return new Flyweightmap.enterset (size);}};} Static map<string, string> map = new Flyweightmap ();p ublic static map<string, string> capitals () {return Map;} public static map<string, string> capitals (int size) {return select (size);//A partial map}static list<string > names = new arraylist<string> (Map.keyset ()),//All the Names;public static list<string> names () {return n Ames;} A partial listpublic static list<string> names (int size) {return new arraylist<string> (select (size). KeySet ());} /********************main******************************/public static void Main (string[] args) {System.out.println ( Capitals (10)); System.out.println (Names (10)); System.out.println (New hashmap<string, string> (Capitals (3))); System.out.println (New treemap<string, string> (Capitals (3))); System.out.println (New linkedhashmap<string, string> (Capitals (3))); System.out.println (New hashtable<string, string> (Capitals (3))); System.out.println (New hashset<string> (names (6))); System.out.println (New Treeset<string> (Capitals (6). KeySet ())); System.out.println (New linkedhashset<string> (names (6)));//System.out.println (new hashtable<string, String> (Capitals (3))); System.out.println (New arraylist<string> (names (6))); System.out.println (New linkedlist<string> (names (6))); SYSTEM.OUT.PRINTLN (capitals (). Get ("F"));}} /**output:{a=a, B=b, C=c, D=d, E=e, F=f, G=g, H=h, I=i, J=j}[a, B, C, D, E, F, G, H, I, J]{a=a, B=b, C=c}{a=a, B=b, C=c}{a=a, B=b, C=c}{a=a, C=c, B=b}[d, E, F, A, B, C][a, B, C, D, E, F][a, B, C, D, E, F][a, B , C, D, E, F][a, B, C, D, E, f]f*/

Package Org.rui.collection3.map;import java.util.abstractlist;/*** * It can have any size and is pre-initialized efficiently with integer data * @author Lenovo * */public class Countingintegerlist extends abstractlist<integer>{private int size;public countingintegerlist (int size) {this.size=size<0?0:size;} @Overridepublic an Integer get (int index) {return integer.valueof (index);} @Overridepublic int size () {return size;} public static void Main (string[] args) {System.out.println (new Countingintegerlist (30));}} /**output: * [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ten, one,,,, * 16, 17,  18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29] * */

Package Org.rui.collection3.map;import Java.util.abstractmap;import Java.util.linkedhashset;import java.util.Map; Import java.util.set;/** * This is using Linkedhashset instead of the custom Set class, so the element is not fully implemented * @author Lenovo * */public class Countingmapdata Ext  Ends Abstractmap<integer, string>{private int size;private static string[] chars = "A B C D E F G". Split ("");p ublic Countingmapdata (int size) {if (size < 0) This.size = 0;this.size = size;} private static class Entry implements Map.entry<integer, String>{private int index; Entry (int index) {this.index = index;} @Overridepublic Integer GetKey () {return index;} @Overridepublic String GetValue () {return chars[index% chars.length]+ integer.tostring (index/chars.length);} @Overridepublic string SetValue (string value) {throw new Unsupportedoperationexception ();} @Overridepublic boolean equals (Object obj) {return integer.valueof (index). Equals (obj); @Overridepublic int hashcode () {return integer.valueof (index). Hashcode ();}} @Overridepublic Set<java.util.map.Entry<integer, string>> EntrySet () {//Linedhashset reserved Initialization order Set<map.entry<integer, String>> Entries = new Linkedhashset<map.entry<integer, string>> (); for (int i = 0; i < size; i++) {Entries.Add (new En) Try (i)); return entries;} public static void Main (string[] args) {System.out.println (new Countingmapdata (60));}} /** * {0=a0, 1=b0, 2=c0, 3=d0, 4=e0, 5=f0, 6=g0, 7=A1, * 8=b1, 9=C1, 10=d1, 11=e1, 12=f1, 13=g1, 14=A2, 15=B2, * 16=c2, 17=D2, 18=e2, 19=f2, 20=g2, 21=a3, 22=B3, 23=C3, * 24=d3, 25=e3, 26=f3, 27=g3, 28=a4, 29=b4, 30=C4, 31=d4, * 32=E4, 33 = F4, 34=g4, 35=a5, 36=b5, 37=c5, 38=D5, 39=e5, * 40=f5, 41=g5, 42=a6, 43=b6, 44=c6, 45=d6, 46=e6, 47=f6, * 48=g6, 49=A 7, 50=b7, 51=c7, 52=d7, 53=e7, 54=f7, 55=g7, * 56=a8, 57=b8, 58=c8, 59=D8} * */

Java container in-depth study using the abstract class customization