Prototype妯″紡鐨勪綔鐢ㄦ湁浜涢浼間笂闈㈢殑鎻忚堪錛屾?zhèn)ㄥ湪鐖稒鍨鍒ヤ腑瀹毦煩涓鍊媍lone()鏂規(guī)硶錛岃屽湪瀛愰鍒ヤ腑閲嶆柊瀹氱京瀹冿紝鐣跺鎴剁灝嶆柤鎵鐢㈢敓鐨勭墿浠舵湁鑸堣叮涓︽兂鍔犱互鍒╃敤錛岃屾?zhèn)ㄥ張涓嶆兂鐮村鍘熶締鐨勭墿錃g錛屾?zhèn)ㄥ彲浠ョ敘鐢熶竴鍊嬬墿浠剁殑瑜囨湰緄﹀畠銆?br>
Prototype鍏鋒湁灞曠ず鐨勬剰鍛籌紝灝卞儚鏄睍瑕芥渻涓婄殑鍘熷瀷杌婃錛岀暥鎮(zhèn)ㄥ皪鏌愬嬭粖嬈炬劅鑸堣叮鏅傦紝鎮(zhèn)ㄥ彲浠ヨ臣璨風(fēng)浉鍚屾紺虹殑杌婏紝鑰屼笉鏄粖灞曚笂鐨勮粖銆?br>
鍦ㄨ粺楂旇ō璦堜笂鐨勪緥瀛愭渻鏇存竻妤氱殑瑾槑鐐轟綍瑕侀茶鐗╀歡瑜囪＝錛屽亣璦?zhèn)ㄨ瑷a堜竴鍊嬪鍏цō璦堣粺楂旓紝杌熼珨涓湁涓鍊嬪睍紺哄鍏風(fēng)殑宸ュ叿鍒楋紝鎮(zhèn)ㄥ彧瑕侀粸閬稿伐鍏峰垪灝卞彲浠ョ敘鐢熶竴鍊嬪鍏瘋鏈紝渚嬪涓寮?jí)|瀛愭垨妗屽瓙錛屾?zhèn)ㄥ彲浠ユ嫋鏇抽欏嬭瑁界殑鐗╀歡鑷寵ō璦堝湒涓紝闅ㄦ檪鏀硅畩瀹冪殑浣嶇疆銆侀鑹茬瓑絳夛紝鐣舵?zhèn)ㄦ敼璁姯a▓鍦栦腑鐨勭墿浠舵檪錛屽伐鍏峰垪涓婄殑鍘熷瀷宸ュ叿鍒楁槸涓嶆渻璺熻憲涓璧鋒敼璁婄殑錛岄欏嬮亾鐞嗘槸鐒￠渶瑙ｉ噵鐨勩?br>
涓嬮潰鐨?UML 欏炲垾鍦栬〃紺轟簡(jiǎn)涓婅堪鐨勭啊鍠蹇碉細(xì)
Prototype妯″紡鐨勯噸榛炲湪鏂糲lone()錛屽畠璨犺鉑瑜囪＝鐗╀歡鏈韓涓﹀偝鍥烇紝浣嗛欏媍lone()鏈韓鍦ㄥ浣滀笂瀛樺湪涓浜涘洶闆ｏ紝灝ゅ叾鏄暥鐗╀歡鏈韓鍙堢辜鎵垮彟涓鍊嬬墿浠舵檪錛屽浣曠⒑淇濊瑁界殑鐗╀歡瀹屾暣鐒¤錛屽湪涓嶅悓鐨勭▼寮忚獮璦涓湁涓嶅悓鐨勪綔娉曘?br>
鍦↗ava涓殑浣滄硶鏄忛亷瀵︿綔涓鍊婥loneable浠嬮潰錛屽畠鍙槸涓鍊嬭伈鏄庣殑浠嬮潰錛屼甫鐒¤瀹氫換浣曞浣滅殑鏂規(guī)硶錛屾?zhèn)ㄧ殑鐩殑鏄敼瀵玂bject鐨刢lone ()鏂規(guī)硶錛屼嬌鍏跺叿鍌欐湁瑜囪＝鐗╀歡鐨勫姛鑳斤紝閫欏嬫柟闈㈠緩璀版?zhèn)ㄥ弮鑰冿細(xì)How to avoid traps and correctly override methods from java.lang.Object銆?br>
鐢ㄤ竴鍊嬬啊鍠殑渚嬪瓙渚嗗浣滀笂鍦栦腑鐨勭祼妲嬶紝閫欏嬩緥瀛愬埄鐢ㄤ簡(jiǎn)Java瑾炶█鏈韓鐨刢lone鐗規(guī)э細(xì)
鍦↗ava涓殑浣滄硶鏄忛亷瀵︿綔涓鍊婥loneable浠嬮潰錛屽畠鍙槸涓鍊嬭伈鏄庣殑浠嬮潰錛屼甫鐒¤瀹氫換浣曞浣滅殑鏂規(guī)硶錛屾?zhèn)ㄧ殑鐩殑鏄敼瀵玂bject鐨刢lone ()鏂規(guī)硶錛屼嬌鍏跺叿鍌欐湁瑜囪＝鐗╀歡鐨勫姛鑳斤紝閫欏嬫柟闈㈠緩璀版?zhèn)ㄥ弮鑰冿細(xì)How to avoid traps and correctly override methods from java.lang.Object銆?br>
鐢ㄤ竴鍊嬬啊鍠殑渚嬪瓙渚嗗浣滀笂鍦栦腑鐨勭祼妲嬶紝閫欏嬩緥瀛愬埄鐢ㄤ簡(jiǎn)Java瑾炶█鏈韓鐨刢lone鐗規(guī)э細(xì)
- AbstractFurniture.java
public abstract class AbstractFurniture
implements Cloneable {
public abstract void draw();
// 鍦―esign Pattern涓婏紝浠ヤ笅鐨刢lone鏄娊璞℃湭瀵︿綔鐨?br> // 瀵﹂殯涓婂湪Java涓璫lass閮界辜鎵胯嚜Object
// 鎵浠ュ湪閫欓倞鎴戝戠洿鎺ラ噸鏂板畾緹ヽlone()
// 閫欐槸鐐轟簡(jiǎn)絎﹀悎Java鐝捐鐨刢lone姍熷埗
protected Object clone() throws CloneNotSupportedException {
return super.clone();
}
}
CircleTable鑸嘢quareTable綣兼壙浜?jiǎn)AbstractFurniture錛屼甫瀵︿綔clone鏂規(guī)硶錛岀敤鏂煎偝鍥炴湰韜殑瑜囪＝鍝侊細(xì)
- CircleTable.java
import java.awt.*;
public class CircleTable extends AbstractFurniture {
protected Point center;
public void setCenter(Point center) {
this.center = center;
}
protected Object clone ()
throws CloneNotSupportedException {
Object o = super.clone();
if(this.center != null) {
((CircleTable) o).center = (Point) center.clone();
}
return o;
}
public void draw() {
System.out.println("\t鍦撴\t涓績(jī)錛?" + center.getX()
+ ", " + center.getY()+ ")");
}
}
- SquareTable.java
import java.awt.*;
public class SquareTable extends AbstractFurniture {
protected Rectangle rectangle;
public void setRectangle(Rectangle rectangle) {
this.rectangle = rectangle;
}
protected Object clone ()
throws CloneNotSupportedException {
Object o = super.clone();
if(this.rectangle != null) {
((SquareTable) o).rectangle = (Rectangle) rectangle.clone();
}
return o;
}
public void draw() {
System.out.print("\t鏂規(guī)\t浣嶇疆錛?" + rectangle.getX()
+ ", " + rectangle.getY()+ ")");
System.out.println(" / 瀵珮錛?" +
rectangle.getWidth()
+ ", " + rectangle.getHeight()+ ")");
}
}
House鏄嬭櫅鎿殑鎴垮眿鐗╀歡錛屽緸Prototype瑜囪＝鍑轟締鐨勭墿浠跺姞鍏ヨ嚦House涓細(xì)
- House.java
import java.util.*;
public class House {
private Vector vector;
public House() {
vector = new Vector();
}
public void addFurniture(AbstractFurniture furniture) {
vector.addElement(furniture);
System.out.println("鐝炬湁瀹跺叿....");
Enumeration enumeration = vector.elements();
while(enumeration.hasMoreElements()) {
AbstractFurniture f =
(AbstractFurniture) enumeration.nextElement();
f.draw();
}
System.out.println();
}
}
鍐嶄締鏄噳鐢ㄧ▼寮忔湰韜細(xì)
- Application.java
import java.awt.*;
public class Application {
private AbstractFurniture circleTablePrototype;
public void setCircleTablePrototype(
AbstractFurniture circleTablePrototype) {
this.circleTablePrototype = circleTablePrototype;
}
public void runAppExample() throws Exception {
House house = new House();
CircleTable circleTable = null;
// 寰炲伐鍏峰垪閬告搰涓鍊嬪鍏峰姞鍏ユ埧瀛愪腑
circleTable =
(CircleTable) circleTablePrototype.clone();
circleTable.setCenter(new Point(10, 10));
house.addFurniture(circleTable);
// 寰炲伐鍏峰垪閬告搰涓鍊嬪鍏峰姞鍏ユ埧瀛愪腑
circleTable =
(CircleTable) circleTablePrototype.clone();
circleTable.setCenter(new Point(20, 30));
house.addFurniture(circleTable);
}
public static void main(String[] args) throws Exception {
Application application = new Application();
application.setCircleTablePrototype(
new CircleTable());
application.runAppExample();
}
}
Java涓殑clone()鏂規(guī)硶鏄辜鎵胯嚜Object錛孉bstractFurniture鐨勫瓙欏炲垾鍓噊verride閫欏媍lone()鏂規(guī)硶錛屼互瑜囪＝鍏舵湰韜甫鍌沖洖銆?br>
涓嬪湒鐐篜rototype妯″紡鐨勯鍒ョ祼妲嬪湒錛?
鍦?Gof 鐨勮ō璦堟ā寮忔浉涓鄲鍑轟竴鍊嬪師鍨嬫ā寮忕殑鎳夌敤錛氫竴鍊嬮氱敤鐨勫湒鍨嬬法杓櫒 Framework銆傚湪閫欏?Framework涓湁涓鍊嬪伐鍏峰垪錛屾?zhèn)ㄥ彲浠ュ湪涓婇潰閬告搰闊虫▊绗﹁櫉浠ュ姞鍏ユ▊璀滀腑锛屼甫鍙互闅ㄦ檪瑾挎暣闊虫▊绗﹁櫉鐨勪綅缃{夌瓑銆?br>
鍦栧瀷綬ㄨ集鍣‵ramework鏄氱敤鐨勶紝鐒惰屽畠涓︿笉鐭ラ亾閫欎簺闊蟲(chóng)▊絎﹁櫉鐨勫瀷鎱嬶紝鏈変漢鎴栬ū鏈冩兂鍒扮辜鎵垮湒鍨嬬法杓櫒Framework渚嗙偤姣忓嬮煶妯傜铏熻ō璦堜竴鍊嬫鏋跺瓙欏炲垾錛屼絾鐢辨柤闊蟲(chóng)▊絎﹁櫉鐨勭ó欏炲緢澶氾紝閫欐渻鐢㈢敓鐩哥暥澶氱殑瀛愰鍒ワ紝鐐轟簡(jiǎn)閬垮厤閫欑ó鎯呮硜錛屽彲浠ラ忛亷Prototype妯″紡渚嗘笡灝戝瓙欏炲垾鐨勬暩鐩紝鍙互璦▓鍑轟互涓嬬殑緄愭錛?br>
鍦栧瀷綬ㄨ集鍣‵ramework鏄氱敤鐨勶紝鐒惰屽畠涓︿笉鐭ラ亾閫欎簺闊蟲(chóng)▊絎﹁櫉鐨勫瀷鎱嬶紝鏈変漢鎴栬ū鏈冩兂鍒扮辜鎵垮湒鍨嬬法杓櫒Framework渚嗙偤姣忓嬮煶妯傜铏熻ō璦堜竴鍊嬫鏋跺瓙欏炲垾錛屼絾鐢辨柤闊蟲(chóng)▊絎﹁櫉鐨勭ó欏炲緢澶氾紝閫欐渻鐢㈢敓鐩哥暥澶氱殑瀛愰鍒ワ紝鐐轟簡(jiǎn)閬垮厤閫欑ó鎯呮硜錛屽彲浠ラ忛亷Prototype妯″紡渚嗘笡灝戝瓙欏炲垾鐨勬暩鐩紝鍙互璦▓鍑轟互涓嬬殑緄愭錛?br>
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鎮(zhèn)ㄥ彲浠ュ湪紼嬪紡涓畾緹╁叐鍊嬭鑹詫紝涓鍊嬫槸鎸囧皫榪峰寤虹珛鐨凞irector瑙掕壊錛屼竴鍊嬫槸鎸夌収鎸囧皫鑰呮寚紺哄緩绔嬭糠瀹殑Builder瑙掕壊錛孌irector鏍規(guī)摎瀹氱京鐨勮糠瀹櫍鍒椾締鎸囧皫Builder錛屽彧瑕佹洿鎻汢uilder錛屽氨鍙互瀹屾垚涓嶅悓鏉愯唱鐨勮糠瀹?br>
鍙互浣跨敤涓嬮潰鐨刄ML 欏炲垾鍦栦締琛ㄧず涓婅堪鐨勬蹇碉細(xì)
- MazeDirector.java
public class MazeDirector {
private int[][] maze;
private IMazeBuilder mazeBuilder;
public void setMaze(int[][] maze) {
this.maze = maze;
}
public void setMazeBuilder(IMazeBuilder mazeBuilder) {
this.mazeBuilder = mazeBuilder;
}
public void buildMaze() {
for(int i = 0; i < maze.length; i++) {
for(int j = 0; j < maze[i].length; j++) {
// 鐢辨柤mazeBuilder鏄疘MazeBuilder鍨嬫厠
// 鎵浠ョ劇璜朆uilder瀵︿緥鐐轟綍錛岄欓倞鐨勭▼寮忛兘鐒￠渶璁婂嫊
switch (maze[i][j]) {
case 0:
mazeBuilder.createRoadBlock();
break;
case 1:
mazeBuilder.createWallBlock();
break;
case 2:
mazeBuilder.createTreasureBlock();
break;
default:
System.out.println("undefined");
}
}
mazeBuilder.nextRow();
}
}
}
- IMazeBuilder.java
public interface IMazeBuilder {
public void createRoadBlock();
public void createWallBlock();
public void createTreasureBlock();
public void nextRow();
}
- SoliderMazeBuilder.java
public class SolidMazeBuilder implements IMazeBuilder {
public void createWallBlock() {
System.out.print("鈻?);
}
public void createRoadBlock() {
System.out.print("銆");
}
public void createTreasureBlock() {
System.out.print("$ ");
}
public void nextRow() {
System.out.println();
}
}
- DiamondMazeBuilder.java
public class DiamondMazeBuilder implements IMazeBuilder {
public void createWallBlock() {
System.out.print("鈼?);
}
public void createRoadBlock() {
System.out.print("銆");
}
public void createTreasureBlock() {
System.out.print("* ");
}
public void nextRow() {
System.out.println();
}
}
浣跨敤涓嬮潰鐨勭▼寮忎締娓│涓涓嬶紝瀹冨皣鐢㈢敓鍏╁嬭糠瀹湒褰細(xì)
public class Main {
public static void main(String[] args) {
int[][] maze = {{1, 1, 1, 1, 1, 1, 1},
{1, 0, 0, 0, 0, 2, 1},
{1, 0, 1, 0, 1, 0, 1},
{1, 0, 2, 1, 0, 1, 1},
{1, 1, 0, 1, 0, 1, 1},
{1, 0, 0, 2, 0, 0, 1},
{1, 1, 1, 1, 1, 1, 1}};
MazeDirector mazeDirector = new MazeDirector();
mazeDirector.setMaze(maze);
System.out.println("Build SolidMaze....");
mazeDirector.setMazeBuilder(new SolidMazeBuilder());
mazeDirector.buildMaze();
System.out.println("Build DiamondMaze....");
mazeDirector.setMazeBuilder(
new DiamondMazeBuilder());
mazeDirector.buildMaze();
}
}
鍦ㄨ糠瀹緥瀛愪腑涓︽矑鏈夌敘鐢熸垨榪斿洖鐢㈠搧鐗╀歡錛岄欒鎮(zhèn)ㄧ殑闇姹傝屽畾錛岃糠瀹緥瀛愬彧鏄皣緄愭灉杓稿嚭鑷充富鎺у彴錛屾?zhèn)ㄤ篃鍙互瑷a堜竴鍊嬬敘鍝佺墿浠訛紝鎴栨槸灝囩祼鏋滅洿鎺ヨ幾鍑虹偤鏂囦歡銆?br>
鍦?a > Gof 涓湁緄﹀嚭浜?jiǎn)涓鍊嬩笉閷殑渚嬪瓙錛屼互璦▓鏂囦歡鍓栨瀽鍣ㄧ偤渚嬶紝瑭插墫鏋愬櫒鍙互灝囨枃浠惰綁鎻涚偤鍏跺畠鐨勬牸寮忥紝浠OC鏂囦歡鍓栨瀽鍣ㄧ偤渚嬪ソ浜?jiǎn)锛屽亣瑷笇鏈涙瀽鍓栧櫒鍙互灏嘍OC鏂囦歡杞夋彌鐐篟TF鎴栨槸PDF鏂囦歡錛屽彲浠ュ涓嬭ō璦堢祼妲嬶細(xì)
綈″柈渚嗚錛屽緩綃夎呮ā寮忛仼鐢ㄧ殑鍫村悎錛屽湪鏂間嬌寰楁?zhèn)ㄥ彲浠ヤ緷璩存娊璞＄殑寰徑媺钘嶅湒锛岃屽闅涘緩閫犳檪鍙互浣跨敤涓嶅悓鐨勫渚嬶紝閫欐槸鍏朵箣鎵浠ュ懡鐐築uilder鐨勫師鍥?
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寰堝鏅傚欙紝鎮(zhèn)ㄦ渻闇瑕丼ingleton妯″紡錛屼緥濡傚嵃琛ㄦ綆＄悊錛屾?zhèn)ㄥ笇鏈浗E嬪紡涓彧鑳芥湁涓鍊婸rint Spooler錛屼互閬垮厤鍏╁嬪垪鍗板嫊浣滃悓鏅傝幾鍏ヨ嚦鍗拌〃姍熶腑錛涗緥濡傝硣鏂欏韓綆＄悊錛屽洜鐐哄緩绔嬮ｆ帴錛圕onnection錛夌墿浠舵渻鑰楃敤璩囨簮錛屾?zhèn)ㄥ笇鏈浗E嬪紡涓彧鑳芥湁涓鍊嬮ｆ帴鐗╀歡錛屾墍鏈夊叾瀹冪殑紼嬪紡閮介忛亷閫欏嬬墿浠朵締閫ｆ帴璩囨枡搴紝浠ラ伩鍏嶉ｆ帴鐗╀歡鐨勯噸瑜囬枊鍟熼犳垚璩囨簮鐨勮楃敤錛涗緥濡傜郴緄辯▼寮忓爆鎬ф獢鐨勮畝鍙栵紝鎮(zhèn)ㄤ嬌鐢ㄥ柈涓鍊嬬墿浠朵締璁鍙栧爆鎬у収瀹癸紝鑰岀▼寮忕殑鍏跺畠閮ㄤ喚閮藉悜閫欏嬬墿浠惰姹傚爆鎬ц硣鏂欙紝鑰屼笉鏄嚜琛岃畝鍙栧爆鎬ц硣鏂欍?br>
浠ュ嵃琛ㄦ璦▓鐐轟緥錛屾湁鐨勮ō璦堜漢鍝℃渻鎺″彇鍏ㄥ煙璁婃暩鐨勬柟寮忎締寤虹珛瀵︿緥錛屼甫鍦ㄧ▼寮忎腑闅ㄦ鍙栫敤閫欏嬪渚嬶紝Java闆栫劧涓嶆敮鎻村叏鍩熻畩鏁革紝浣嗛忛亷灝囩墿浠跺寘瑁濆湪涓鍊嬮鍒ヤ箣涓紝涔熸湁浜烘渻鎺＄敤閫欐ǎ鐨勫娉曪細(xì)
public class PrintSpooler {
public PrintSpooler() {
// ....
}
public Connection getSpooler(){
....
}
}
public class GlobalObject {
private PrintSpooler printSpooler;
public GlobalObject () {
printSpooler = new PrintSpooler();
...
}
public void getPrintSpooler() {
return printSpooler;
}
}
鐒¤珫鍏ㄥ煙璁婃暩鎴栨槸浠ヤ笂鐨勪緥瀛愶紝閮界劇娉曚繚璀夊彧鐢㈢敓鍞竴鍊嬪渚嬶紝鎮(zhèn)ㄤ篃璦辨渻娉ㄦ剰涓嶇姱閫欏嬮尟瑾わ紝浣嗚垏鎮(zhèn)ㄥ叡鍚屽伐浣滅殑澶ヤ即涔熻ū鏈冪洿瑕虹殑浣跨敤寤烘鏂規(guī)硶渚嗙敘鐢熶竴鍊?PrintSpooler瀵︿緥銆?br>public PrintSpooler() {
// ....
}
public Connection getSpooler(){
....
}
}
public class GlobalObject {
private PrintSpooler printSpooler;
public GlobalObject () {
printSpooler = new PrintSpooler();
...
}
public void getPrintSpooler() {
return printSpooler;
}
}
Singleton妯″紡鍙互淇濊瓑涓鍊嬮鍒ュ彧鏈変竴鍊嬪渚嬶紝涓︽彁渚涗竴鍊嬭í鍟忥紙visit錛夐欏嬪渚嬬殑鏂規(guī)硶銆?br>
涓鍊婼ingleton瀵︿綔鍗崇偤Java涓殑java.lang.Runtime欏炲垾錛屾瘡鍊婮ava紼嬪紡鍩瘋鏅傞兘鏈変竴鍊嬪敮涓鐨凴untime鐗╀歡錛屽彲浠ラ忛亷瀹冩彁渚涚殑闈滄厠鏂規(guī)硶getRuntime()鏂規(guī)硶渚嗗彇寰楅欏嬬墿浠訛紝渚嬪錛?
Runtime runtime = Runtime.getRuntime();
鍙栧緱Runtime鐗╀歡涔嬪緦錛屾?zhèn)ㄥ彲浠ラ忛亷瀹冮茶涓浜涘閮ㄥ懡浠ょ殑鍩瘋銆侀茶鍨冨溇铏曠悊絳夌瓑鎸囦護(hù)錛屾?zhèn)ㄥ彲浠ラ枊鍟烺untime.java欏炲垾錛岄枊闋殑騫捐鏄欐ǎ瀵殑錛?br>
public class Runtime {
private static Runtime currentRuntime = new Runtime();
public static Runtime getRuntime() {
return currentRuntime;
}
/** Don't let anyone else instantiate this class */
private Runtime() {}
// 浠ヤ笅鐣?
}
private static Runtime currentRuntime = new Runtime();
public static Runtime getRuntime() {
return currentRuntime;
}
/** Don't let anyone else instantiate this class */
private Runtime() {}
// 浠ヤ笅鐣?
}
涓婇潰緄愭鍗蟲(chóng)帯鐢⊿ingleton妯″紡璦▓錛屽叾緄愭浣跨敤 UML 渚嗚〃鍗沖涓嬫墍紺猴細(xì)
鏈夊咕鍊嬪浣滀笂闈㈢祼妲嬬殑鏂規(guī)硶錛屽彲浠ュ湪絎竴嬈￠渶瑕佸渚嬫檪鍐嶅緩绔嬬墿浠訛紝涔熷氨鏄帯鐢ㄦ墍瓔傜殑Lazy Initialization錛?br>
public class Singleton {
private static Singleton instance = null;
private Singleton() {
// ....
}
public static Singleton getInstance() {
if (instance == null) {
instance = new Singleton();
}
return instance;
}
// .. 鍏跺畠瀵︿綔
}
private static Singleton instance = null;
private Singleton() {
// ....
}
public static Singleton getInstance() {
if (instance == null) {
instance = new Singleton();
}
return instance;
}
// .. 鍏跺畠瀵︿綔
}
涓婇潰鐨勫浣滈仼鐢ㄦ柤鍠煼琛岀窉鐨勭▼寮忥紝鍦ㄥ鍩瘋綬掔殑紼嬪紡涓嬶紝浠ヤ笅鐨勫娉曞湪澶氬嬪煼琛岀窉鐨勭鐖硣婧愪笅錛屽皣浠嶆湁鍙兘鐢㈢敓鍏╁嬩互涓婄殑瀵︿緥錛屼緥濡備笅闈㈢殑鎯呮硜錛?br>
Thread1: if(instance == null) // true
Thread2: if(instance == null) // true
Thread1: instance = new Singleton(); // 鐢㈢敓涓鍊嬪渚?/span>
Thread2: instance = new Singleton(); // 鍙堢敘鐢熶竴鍊嬪渚?/span>
Thread1: return instance; // 鍥炲偝涓鍊嬪渚?/span>
Thread2: return instance; // 鍙堝洖鍌充竴鍊嬪渚?/span>
Thread2: if(instance == null) // true
Thread1: instance = new Singleton(); // 鐢㈢敓涓鍊嬪渚?/span>
Thread2: instance = new Singleton(); // 鍙堢敘鐢熶竴鍊嬪渚?/span>
Thread1: return instance; // 鍥炲偝涓鍊嬪渚?/span>
Thread2: return instance; // 鍙堝洖鍌充竴鍊嬪渚?/span>
鍦ㄥ鍩瘋綬掔殑鐠板涓嬶紝鐐轟簡(jiǎn)閬垮厤璩囨簮鍚屾檪绔剁埈鑰屽皫鑷村涓婄敘鐢熷鍊嬪渚嬬殑鎯呮硜錛屽姞涓婂悓姝ワ紙synchronized錛夋鍒訛細(xì)
public class Singleton {
private static Singleton instance = null;
private Singleton(){}
synchronized static public Singleton getInstance() {
if (instance == null) {
instance = new Singleton();
}
return instance;
}
}
private static Singleton instance = null;
private Singleton(){}
synchronized static public Singleton getInstance() {
if (instance == null) {
instance = new Singleton();
}
return instance;
}
}
涓嶉亷閫欑ó綈″柈鐨勫娉曚笉閬╁悎鐢ㄦ柤鍍忎己鏈嶅櫒閫欑ó鏈嶅嫏寰堝鍩瘋綬掔殑紼嬪紡涓婏紝鍚屾姍熷埗鏈冮犳垚鐩哥暥鐨勬晥鑳戒綆钀斤紝鐐轟簡(jiǎn)欏у強(qiáng)Singleton銆丩azy Initialization鑸囨晥鑳藉晱欏岋紝鍥犺屾湁浜?jiǎn)Double-check Locking鐨勬ā寮忥細(xì)
public class Singleton {
private static Singleton instance = null;
private Singleton(){}
public static Singleton getInstance() {
if (instance == null){
synchronized(Singleton.class){
if(instance == null) {
instance = new Singleton();
}
}
}
return instance;
}
}
private static Singleton instance = null;
private Singleton(){}
public static Singleton getInstance() {
if (instance == null){
synchronized(Singleton.class){
if(instance == null) {
instance = new Singleton();
}
}
}
return instance;
}
}
Java涓璕untime欏炲垾鐨勪綔娉曞氨綈″柈澶氫簡(jiǎn)錛屽畠鎹ㄦ浜?jiǎn)Lazy Initialization錛屽鏋滄?zhèn)ㄧ殑瀵︿緥鍒濆鍖栦笉鏄緢涔呯殑瑭卞Q屽彲浠ョ敤閫欑ó鏂瑰紡錛?br>
public class Singleton {
private static Singleton instance = new Singleton();
private Singleton() {
// ....
}
public static Singleton getInstance() {
return instance;
}
// 鍏跺畠瀵︿綔
}
private static Singleton instance = new Singleton();
private Singleton() {
// ....
}
public static Singleton getInstance() {
return instance;
}
// 鍏跺畠瀵︿綔
}
Singleton鏈韓鐨勮蹇電啊鍠絾鎳夌敤寰堝唬錛屽洜鑰屽緢澶氭檪鍊欏繀闋堝皪瀵﹂殯鐠板浣滀竴浜涜冮噺鑸囪鏁達(dá)紝寤鴻鎮(zhèn)ㄤ篃鐪嬬湅鏈夐棞鏂糞ingleton鐨勯欑瘒 璦庤珫銆?br>
]]>
public class Singleton {
private static Singleton instance = null;
private Singleton() {
// ....
}
public static Singleton getInstance() {
if (instance == null) {
// getEnv琛ㄧず緋葷當(dāng)鐠板璁婃暩
String style = getEnv("style");
if (style.equals("child1"))
instance = new ChildSingleton1();
else if (style.equals("child2r"))
instance = new ChildSingleton2();
else
instance = new Singleton();
}
return _instance;
}
// ....
}
private static Singleton instance = null;
private Singleton() {
// ....
}
public static Singleton getInstance() {
if (instance == null) {
// getEnv琛ㄧず緋葷當(dāng)鐠板璁婃暩
String style = getEnv("style");
if (style.equals("child1"))
instance = new ChildSingleton1();
else if (style.equals("child2r"))
instance = new ChildSingleton2();
else
instance = new Singleton();
}
return _instance;
}
// ....
}
涓婇潰閫欏嬬▼寮忕墖孌墊敼瀵嚜 Gof 鏇?/a>涓棞鏂糞ingleton鐨勪緥瀛愶紝涓︾敤Java瀵︾従錛涘湪鏇鎬腑鎸囧嚭錛岄欏嬩緥瀛愮殑緙洪粸鏄瘡澧炲姞涓鍊嬪瓙欏炲垾錛実etInstance()灝卞繀闋堥噸鏂頒慨鏀癸紝閫欏嬪晱欏屽湪Java涓彲浠ヤ嬌鐢≧eflection姍熷埗渚嗚В姹猴細(xì)
public class Singleton {
private static Singleton instance = null;
private Singleton() {
// ....
}
public static Singleton getInstance() {
if (instance == null) {
// getEnv琛ㄧず鐠板璁婃暩
String style = getEnv("style");
try {
instance = (Singleton)
Class.forName(style).newInstance();
}
catch(Exception e) {
System.out.println(
"Sorry! No such class defined!");
}
}
return instance;
}
// ....
}
private static Singleton instance = null;
private Singleton() {
// ....
}
public static Singleton getInstance() {
if (instance == null) {
// getEnv琛ㄧず鐠板璁婃暩
String style = getEnv("style");
try {
instance = (Singleton)
Class.forName(style).newInstance();
}
catch(Exception e) {
System.out.println(
"Sorry! No such class defined!");
}
}
return instance;
}
// ....
}
涓婇潰鐨勬柟寮忎嬌鐢ㄤ簡(jiǎn)Java鐨凴eflection姍熷埗錛屼甫閫忛亷鐠板璁婃暩璦畾瑕佺敘鐢熺殑瀛愰Singleton錛屽鏋滀笉浣跨敤Reflection鐨勮┍錛孏of 鏇鎬腑鎻愬嚭鐨勬敼閫叉柟娉曟槸浣跨敤Registry of Singleton鏂規(guī)硶錛?br>
import java.util.*;
public class Singleton {
// 璦誨唺琛紝鐢ㄦ柤璦誨唺瀛愰鍒ョ墿浠?/span>
private static Map registry = new HashMap();
private static Singleton instance;
public static void register(
String name, Singleton singleton) {
registry.put(name, singleton);
}
public static Singleton getInstance() {
if (instance == null) {
// getEnv琛ㄧず鍙栧緱鐠板璁婃暩
String style = getEnv("style");
instance = lookup(style);
}
return instance;
}
protected static Singleton lookup(String name) {
return (Singleton) registry.get(name);
}
}
public class Singleton {
// 璦誨唺琛紝鐢ㄦ柤璦誨唺瀛愰鍒ョ墿浠?/span>
private static Map registry = new HashMap();
private static Singleton instance;
public static void register(
String name, Singleton singleton) {
registry.put(name, singleton);
}
public static Singleton getInstance() {
if (instance == null) {
// getEnv琛ㄧず鍙栧緱鐠板璁婃暩
String style = getEnv("style");
instance = lookup(style);
}
return instance;
}
protected static Singleton lookup(String name) {
return (Singleton) registry.get(name);
}
}
鍦℅of鏇鎬腑浣跨敤List渚嗗鐝捐ɑ鍐婅〃錛岃屽湪閫欓倞浣跨敤HasMap欏炲垾渚嗗鐝撅紝瀹冩槸鐢盝ava SE鎵鎻愪緵鐨勶紱鍦ㄧ埗欏炲垾涓彁渚涗竴鍊媟egister() 浠ヨɑ鍐奡ingleton鐨勫瓙欏炲垾鎵鐢㈢敓涔嬪渚嬶紝鑰岃ɑ鍐婄殑鏅傛鍙互鏀懼湪瀛愰鍒ョ殑寤烘鏂規(guī)硶涓姞浠ュ鐝撅紝渚嬪錛?
public class ChildSingleton1 extends Singleton {
public ChildSingleton1() {
// ....
// 璦誨唺瀛愰鍒ョ墿浠?/span>
register(getClass().getName(), this);
}
}
public ChildSingleton1() {
// ....
// 璦誨唺瀛愰鍒ョ墿浠?/span>
register(getClass().getName(), this);
}
}
鑻ヨ鍒╃敤Singleton錛屽墖鍏堜嬌鐢ㄩ欏嬪瓙欏炲垾鐢㈢敓鐗╀歡錛岄欐渻鍚戠埗欏炲垾璦誨唺鐗╀歡錛屼箣寰岄忛亷Singleton鐖墮鍒ヤ締鍙栧緱鐗╀歡錛?br>
// 蹇呴爤鍏堝暉濮嬮欐璦誨唺紼嬪簭
// 鐢㈢敓涓﹁ɑ鍐奀hildSingleton1鐗╀歡
new ChildSingleton1();
// 鐢㈢敓涓﹁ɑ鍐奀hildSingleton2鐗╀歡
new ChildSingleton2();
// 鐢㈢敓涓﹁ɑ鍐奀hildSingleton1鐗╀歡
new ChildSingleton1();
// 鐢㈢敓涓﹁ɑ鍐奀hildSingleton2鐗╀歡
new ChildSingleton2();
// 璦誨唺瀹屾垚錛屽彲浠ヤ嬌鐢ㄧ埗欏炲垾渚嗗彇寰楀瓙欏炵殑Singleton
// 鑷蟲(chóng)柤鍙栧洖浣曞摢涓鍊嬶紝瑕栨?zhèn)ㄧ殑鐠板璁婃暩瑷|焙瀹?/span>
Singleton childSingleton = Singleton.getInstance();
// 鑷蟲(chóng)柤鍙栧洖浣曞摢涓鍊嬶紝瑕栨?zhèn)ㄧ殑鐠板璁婃暩瑷|焙瀹?/span>
Singleton childSingleton = Singleton.getInstance();
閫欑ó鏂瑰紡鐨勭己榛炴槸鎮(zhèn)ㄥ繀闋堝湪紼嬪紡涓暉濮嬩竴孌電▼搴忥紝鍏堝悜鐖墮鍒ヨɑ鍐婂瓙欏炵殑Singleton錛屼箣寰屾墠鑳介忛亷鐖墮鍒ヤ締鍙栧緱鎸囧畾鐨勫瓙欏炲垾Singleton瀵︿緥錛屽ソ铏曟槸鍙互閬╃敤鏂兼矑鏈塕eflection姍熷埗鐨勮獮璦錛屽鏋滄?zhèn)ㄦ儗櫐佹敼璁奡ingleton鐖墮鍌沖洖鐨勫瓙欏濻ingleton錛屽彲浠ュ湪涓婇潰鐨?Singleton欏炲垾涓姞鍏ヤ竴鍊媟eset()鏂規(guī)硶錛屽皣instance璦畾鐐簄ull錛岀劧寰岄噸鏂拌ō瀹氱挵澧冭畩鏁革紝涔嬪緦鍐嶅埄鐢?Singleton鐖墮鐨刧etInstance()鏂規(guī)硶閲嶆柊鍙栧緱璦誨唺琛ㄤ腑鐨勫叾瀹冨瓙欏炪?br>
浜嬪涓奟egistry of Singleton鐨勭湡姝ｅ劒榛炴鍦ㄦ柤姝わ紝鎮(zhèn)ㄥ彲浠ヤ嬌鐢ㄧ埗欏炲垾渚嗙當(dāng)涓綆＄悊澶氬嬬辜鎵跨殑瀛愰鍒ヤ箣Singleton瀵︿緥錛屾?zhèn)ㄥ彲浠ュ湪闇瑕佺殑鏅傚欏啀鍚戠埗欏炲垾璦誨唺瀛愰 Singleton錛屽繀瑕佹檪闅ㄦ檪瑾挎暣鍌沖洖鐨勫瓙欏炲垾Singleton銆?br>
]]>
鎮(zhèn)ㄤ笉鑳藉皣鐢熺敘閫插害鍋滀笅浜?jiǎn)锛岀浉鍙嶇殑鎮(zhèn)ㄥ繀闋埣労瀹氫竴浜涗簨鎯咃紝鎮(zhèn)ㄧ煡閬撴湁闂滄柤铻㈠箷鎺у埗鐨勬墍鏈変粙闈紝鎮(zhèn)ㄥ彲浠ュ皣閫欎簺灝嶄粙闈㈢殑鎿嶄綔婧濋氬厛瀵︾従錛岀瓑鍒拌灑騫曞埌浜?jiǎn)锛岀洿鎺畤铻Ⅱq曡垏鎮(zhèn)ㄧ殑鍗婃垚鍝佺祫鍚堣搗渚嗭紝涓鍊嬪畬鏁寸殑鎴愬搧鍗沖彲鍑哄粻銆?br>
Factory Method妯″紡鍦ㄤ竴鍊嬫娊璞￠涓暀涓嬫煇鍊嬪壍寤哄厓浠剁殑鎶借薄鏂規(guī)硶娌掓湁瀵︿綔錛屽叾瀹冭垏鍏冧歡鎿嶄綔鐩擱棞鑱殑鏂規(guī)硶閮藉厛渚濊炒鏂煎厓浠舵墍瀹氱京鐨勪粙闈紝鑰屼笉鏄緷璩存柤鍏冧歡鐨勫鐝撅紝鐣舵?zhèn)ㄧ殑鎴愬搧涓湁涓鍊嬫垨澶氬嬪厓浠剁劇娉曠⒑瀹氭檪錛屾?zhèn)ㄥ厛纰哄畾鑸囬欎簺鍏冧歡鐨勬搷浣滀粙闈紝鐒跺緦鐢ㄥ厓浠剁殑鎶借薄鎿嶄綔浠嬮潰鍏堝畬鎴愬叾瀹冪殑宸ヤ綔錛屽厓浠剁殑瀵︿綔錛堝鐝撅級(jí)鍓囨帹閬茶嚦瀵︾従鍏冧歡浠嬮潰鐨勫瓙欏炲畬鎴愶紝涓鏃﹀厓浠跺姞鍏ワ紝鍗沖彲瀹屾垚鎮(zhèn)ㄧ殑鎴愬搧銆?br>
鍐嶈垑涓鍊嬩緥瀛愶紝鍋囪ō鎮(zhèn)ㄨ瀹屾垚涓鍊嬫枃浠剁法杓櫒錛屾?zhèn)ㄥ笇鏈涢欏嬬法杓櫒鍙互閬╃敤鏂兼墍鏈夐鍨嬬殑妾旀綬ㄨ集錛屼緥濡俁TF銆丏OC銆乀XT絳夌瓑錛屽剺綆￠欎簺鏂囦歡鏈夎憲涓嶅悓鐨勬牸寮忥紝鎮(zhèn)ㄥ厛紕哄畾鐨勬槸閫欎簺鏂囦歡蹇呯劧鍏峰倷鐨勪竴浜涙搷浣滀粙闈紝渚嬪鍎插瓨銆侀枊鍟熴侀棞闁夌瓑絳夛紝鎮(zhèn)ㄧ敤涓鍊婭Document欏炲瀷渚嗛茶鎿嶄綔錛岄欓杭涓渚嗛欏嬫鏋跺氨鐒￠渶鑰冩叜瀵﹂殯鐨勫劜瀛樸侀枊鍟熺瓑绱扮瘈鏄浣曢茶鐨勩?
浠?UML 欏炲垾鍦栦締琛ㄧ従浠ヤ笅鐨勬蹇碉細(xì)
AbstractEditor涓殑createDocument()鏂規(guī)硶鏄嬫娊璞℃柟娉曪紝鍥犵偤妗嗘灦涓嶇煡閬撴?zhèn)畤瀵︾従涓鍊嬩粈楹奸鍨嬬殑鏂囦歡錛岄欏嬫娊璞℃柟娉曞皣鎺ㄩ伈鑷崇辜鎵緼bstractEditor鐨勫瓙欏炰腑瀵︾従銆?br>
閫欏嬫灦妲嬪彲鐢ㄤ互涓嬬啊鍠殑紺烘剰紼嬪紡渚嗕綔紺虹瘎錛岀暥涓鐝句簡(jiǎn)涓鍊婻TFDocument錛岄洊鐒跺湪AbstractEditor涓甫涓嶇煡閬撴垜鍊戞渻濂楃敤閫欏婻TFDocument錛屼絾鎮(zhèn)ㄥ彲浠ョ湅鍒幫紝閫忛亷澶氬瀷鎿嶄綔錛屾?zhèn)ㄧ殑妗嗘灦鍙互閫茶灝嶆枃浠剁殑鐩擱棞鎿嶄綔銆?br>
- AbstractEditor.java
public abstract class AbstractEditor {
private IDocument document;
public abstract IDocument createDocument();
public void newDocument() {
document = createDocument();
document.open();
}
public void saveDocument() {
if(document != null)
document.save();
}
public void closeDocument() {
if(document != null)
document.close();
}
}
- IDocument.java
public interface IDocument {
public void open();
public void save();
public void close();
}
- RTFEditor.java
public class RTFEditor extends AbstractEditor {
public IDocument createDocument() {
return new RTFDocument();
}
}
- RTFDocument.java
public class RTFDocument implements IDocument {
public RTFDocument() {
System.out.println("寤虹珛RTF鏂囦歡");
}
public void open() {
System.out.println("闁嬪暉鏂囦歡");
}
public void save() {
System.out.println("鍎插瓨鏂囦歡");
}
public void close() {
System.out.println("闂滈枆鏂囦歡");
}
}
灝嘑actory Method鐨勭祼妲嬬躬鍑哄涓嬶細(xì)
Factory Method涓殑AbstractOperator涓搧鏈変竴鍊嬫娊璞＄殑factoryMethod()鏂規(guī)硶錛屽畠璨犺鉑鐢熸垚涓鍊婭Product欏炲瀷鐨勭墿浠訛紝鐢辨柤鐩墠閭勪笉鐭ラ亾灝囧浣曞鐝鵑欏嬮鍨嬶紝鎵浠ュ皣涔嬫帹閬茶嚦瀛愰鍒ヤ腑瀵︾従錛屽湪AbstractOperator涓厛瀵︾従IProduct鎿嶄綔浠嬮潰婧濋氱殑閮ㄤ喚錛屽彧瑕佷粙闈㈢當(dāng)涓浜?jiǎn)锛屽埄鐢ㄥ鍨嬫搷浣滃崨_彲瀹屾垚鍚勭ó涓嶅悓鐨処Product欏炲瀷涔嬬墿浠舵搷浣溿?br>
涔熷氨鏄錛屽皪AbstractOperator渚嗚錛屽叾鎿嶄綔鐨処Product鏄彲浠ユ娊鎻涚殑銆?
]]>
- CustomDialog.java
public class CustomDialog {
private IButton button;
private ITextField textField;
public void setButton(IButton button) {
this.button = button;
}
public void setTextField(ITextField textField) {
this.textField = textField;
}
public void layoutAllComponents() {
// ....
}
public void showDialog() {
this.paintDialog();
button.paintButton();
textField.paintTextField();
}
public void paintDialog() {
System.out.println("custom dialog paints....");
}
}
寰堢啊鍠紝閫欐槸鏈鍩烘湰鐨勪粙闈緷璩達(dá)紝Setter渚濊炒鏂糏Button鑸嘔TextField鍏╁嬩粙闈紝鑰屼笉鏄叾瀵︿綔欏炲垾錛屼笉閬庨欓倞閭勬湁鍊嬮蹭竴姝ョ殑瑕佹眰錛屼嬌鐢ㄤ笂闈㈢殑鏂瑰紡閭勫繀闋堣Κ鑷懠鍙玈etter銆乴ayout絳夋柟娉曪紝鎮(zhèn)ㄥ笇鏈涜鎰熺殑鏇存彌鍙互鏇寸啊鍠簺錛屼緥濡傚彧瑕侀忎竴鍊嬪厓浠剁殑鏇挎彌灝卞彲浠ュ畬鎴愬皪瑭辨柟濉婁笂鎵鏈夊厓浠剁殑瑕栨劅鏇存彌銆?br>
鎮(zhèn)ㄥ彲浠ヤ嬌鐢ˋbstract Factory妯″紡錛屽皣鎵鏈夊皪瑭辨柟濉婃墍闇瑕佺殑鐢㈢敓鐨勫厓浠跺姞浠ュ皝瑁濓紝灝嶈┍鏂瑰渚濊炒鏂糀bstract Factory錛屽闅涗笂鍏烽珨鐨凢actory瀵︾従鍓囧垎鍒ョ敘鐢熷皪瑭辨柟濉婃墍闇瑕佺殑瑕栨劅鍏冧歡錛屼笅闈㈢殑 UML 欏炲垾鍦栧睍鐝鵑欑ó姒傚康銆?br>
鐝懼湪濡傛灉瑕佹洿鎻涙墍鏈夌殑瑕栨劅鍏冧歡錛屽氨鍙鎶借薄鎺夊叿楂旂殑Factory灝卞彲浠ヤ簡(jiǎn)錛屼緥濡傦細(xì)
CustomDialog windowsDialog =
new CustomDialog(new WindowsWidgetFactory());
windowsDialog.showDialog();
CustomDialog macDialog =
new CustomDialog(new MacWidgetFactory());
macDialog.showDialog();
new CustomDialog(new WindowsWidgetFactory());
windowsDialog.showDialog();
CustomDialog macDialog =
new CustomDialog(new MacWidgetFactory());
macDialog.showDialog();
渚嗗皣涓婇潰鐨刄ML鍦栧叿楂斿鐝懼嚭渚嗐?br>
- CustomDialog.java
public class CustomDialog {
private IButton button;
private ITextField textField;
public CustomDialog(IWidgetFactory widgetFactory) {
setWidgetFactory(widgetFactory);
}
// 鐢辨柤瀹㈡埗绔彧渚濊炒鏂兼娊璞＄殑宸ュ粻錛屽伐寤犲浣曞浣滀甫鐒￠棞瀹㈡埗绔殑浜?br> // 瑕佹娊鎻涘伐寤犱甫涓嶉渶瑕佹敼鍕曞鎴剁鐨勭▼寮?br> public void setWidgetFactory(IWidgetFactory widgetFactory) {
setButton(widgetFactory.getButton());
setTextField(widgetFactory.getTextField());
}
public void layoutAllComponents() {
// layout all components
}
// 閫欓倞涔熸槸渚濊炒鎶借薄錛屽闅涙敼璁婁簡(jiǎn)鍏冧歡瀵︿緥
// 瀹㈡埗绔唬紕間篃涓嶇敤鏇存敼
public void setButton(IButton button) {
this.button = button;
}
public void setTextField(ITextField textField) {
this.textField = textField;
}
public void showDialog() {
this.paintDialog();
button.paintButton();
textField.paintTextField();
}
public void paintDialog() {
System.out.println("custom dialog paints....");
}
}
- IButton.java
public interface IButton {
public void paintButton();
}
- ITextField.java
public interface ITextField {
public void paintTextField();
}
- IWidgetFactory.java
public interface IWidgetFactory {
public IButton getButton();
public ITextField getTextField();
}
- MacButton.java
public class MacButton implements IButton {
public void paintButton() {
System.out.println("Mac button paints....");
}
}
- WindowsButton.java
public class WindowsButton implements IButton {
public void paintButton() {
System.out.println("Windows button paints....");
}
}
- MacTextField.java
public class MacTextField implements ITextField {
public void paintTextField() {
System.out.println("Mac textField paints....");
}
}
- WindowsTextField.java
public class WindowsTextField implements ITextField {
public void paintTextField() {
System.out.println("Windows textField paints....");
}
}
- MacWidgetFactory.java
public class MacWidgetFactory implements IWidgetFactory {
public IButton getButton() {
return new MacButton();
}
public ITextField getTextField() {
return new MacTextField();
}
}
- WindowsWidgetFactory.java
public class WindowsWidgetFactory
implements IWidgetFactory {
public IButton getButton() {
return new WindowsButton();
}
public ITextField getTextField() {
return new WindowsTextField();
}
}
涓嬪湒鏄疉bstract Factory妯″紡鐨刄ML緄愭鍦栵細(xì)
綈″柈鐨勮錛屽湪Abstract Factory妯″紡涓皣鍏烽珨鐨凱roduct灝佽鍦ㄥ叿楂擣actory瀵︾従涓紝鑰屽鎴朵粛鍙闈㈠皪Factory鑸嘝roduct鐨勬娊璞′粙闈紝閬垮厤渚濊炒鏂煎叿楂旂殑Factory鑸嘝roduct錛岀敱鏂糉actory灝佽浜?jiǎn)鎵蹇呴爤鐨凱roduct錛屾墍浠ヨ鏇存彌鎺夋墍鏈夌殑鍏冧歡錛屽彧瑕佺啊鍠殑鎶芥彌鎺塅actory灝卞彲浠ヤ簡(jiǎn)錛屼笉鐢ㄤ慨鏀瑰鎴剁鐨勭▼寮忋?br>
]]>
鍋囪ō鏈変竴鍊嬮煶妯傜洅宸ュ粻錛岃臣璨烽煶妯傜洅鐨勫浜轟笉鐢ㄧ煡閬撻煶妯傜洅鏄浣曡＝浣滅殑錛屼粬鍙鐭ラ亾濡備綍鎾斁闊蟲(chóng)▊鐩掑氨鍙互浜?jiǎn)锛屼?UML 欏炲垾鍦栦締琛ㄧず浠ヤ笂鐨勬蹇碉細(xì)
- IMusicBox.java
public interface IMusicBox {
public void play();
}
- PianoBox.java
public class PianoBox implements IMusicBox {
public void play() {
System.out.println("鎾ユ斁閶肩惔闊蟲(chóng)▊:)");
}
}
- ViolinBox.java
public class ViolinBox implements IMusicBox {
public void play() {
System.out.println("鎾ユ斁灝忔彁鐞撮煶妯俕_^");
}
}
- MusicBoxFactory.java
public class MusicBoxFactory {
public static IMusicBox createMusicBox(String name)
throws InstantiationException,
IllegalAccessException,
ClassNotFoundException {
// 閫欓倞浣跨敤鐨勬槸Java鐨凴eflection姍熷埗渚嗙敘鐢熷渚?br> // 涓嶉亷瀹㈡埗绔笉鐢ㄧ鍟?br> // 浠ュ緦灝辯畻鏀硅畩浜?jiǎn)閫欓倞鐨勭▼寮忥紝瀹㈡埗绔▼寮忔槸涓嶇敤鏇存敼鐨?br> return (IMusicBox) Class.forName(name).newInstance();
}
}
- MusicBoxDemo.java
public class MusicBoxDemo {
public static void main(String[] args) throws Exception {
playMusicBox(MusicBoxFactory.createMusicBox("PianoBox"));
playMusicBox(MusicBoxFactory.createMusicBox("ViolinBox"));
}
public static void playMusicBox(IMusicBox musicBox) {
musicBox.play();
}
}
鐢辨柤瀹㈡埗绔彧渚濊炒鏂糏MusicBox浠嬮潰錛屾墍浠ュ嵆浣挎?zhèn)ㄦ棩寰屾敼璁婁簡(jiǎn)createMusicBox()涓殑瀵︿綔鏂瑰紡錛屽皪瀹㈡埗绔槸涓榛炲獎(jiǎng)闊夸篃娌掓湁鐨勩?br>
渚嗙湅鐪婼imple Factory鐨勯鍒ョ祼妲嬶細(xì)
瀹㈡埗鍙闈㈠皪Factory錛屽鎴朵緷璩存柤鐢㈠搧浠嬮潰錛岀敘鍝佺殑鍏烽珨瀵︿綔鏄彲浠ヨ垏瀹㈡埗闅旈枊鐨勶紝瀹冨戜篃鏄彲浠ユ娊鎻涚殑銆?br>
]]>