{"id":224,"date":"2017-01-19T18:35:07","date_gmt":"2017-01-19T10:35:07","guid":{"rendered":"http:\/\/www.lixiaodong.com\/?p=224"},"modified":"2025-03-06T11:04:57","modified_gmt":"2025-03-06T03:04:57","slug":"%e8%ae%be%e8%ae%a1%e6%a8%a1%e5%bc%8f-%e7%8a%b6%e6%80%81%e6%a8%a1%e5%bc%8f","status":"publish","type":"post","link":"https:\/\/www.lixiaodong.com\/?p=224","title":{"rendered":"\u8bbe\u8ba1\u6a21\u5f0f-\u72b6\u6001\u6a21\u5f0f"},"content":{"rendered":"

\u8bbe\u8ba1\u6a21\u5f0f\u52063\u5927\u7c7b\uff1a\u521b\u5efa\u578b\u3001\u7ed3\u6784\u6027\u548c\u884c\u4e3a\u578b\u3002\u72b6\u6001\u6a21\u5f0f\u662f\u884c\u4e3a\u578b\u6a21\u5f0f\u7684\u5176\u4e2d\u4e00\u79cd\u3002\u5b83\u9002\u7528\u7684\u573a\u666f\u662f\uff1a\u4e00\u4e2a\u5bf9\u8c61\u7684\u884c\u4e3a\u662f\u7531\u5b83\u7684\u67d0\u4e2a\u72b6\u6001\u51b3\u5b9a\u7684\uff0c\u5f53\u72b6\u6001\u6539\u53d8\u65f6\uff0c\u884c\u4e3a\u4f1a\u968f\u4e4b\u6539\u53d8\u3002
\n\u4e3e\u4e00\u4e2a\u4f8b\u5b50\uff1a\u4e00\u4e2a\u7535\u6247\uff0c\u5b83\u7684\u8f6c\u52a8\u5c31\u662f\u4e00\u4e2a\u884c\u4e3a\u3002\u8fd9\u4e2a\u884c\u4e3a\u7531\u5b83\u6240\u5904\u7684\u6863\u4f4d\u51b3\u5b9a\uff1a1\u6863\u662f\u4f4e\u901f\u8f6c\u52a8\uff0c2\u6863\u662f\u4e2d\u901f\u8f6c\u52a8\uff0c3\u6863\u662f\u9ad8\u901f\u8f6c\u52a8\u3002
\n\u6211\u4eec\u65b0\u5efa\u4e00\u4e2a\u7c7bFan\u8868\u793a\u7535\u6247\uff0c\u8fd9\u4e2a\u7c7b\u6709\u4e00\u4e2a\u65b9\u6cd5rotate()\u8868\u793a\u8f6c\u52a8\u8fd9\u4e2a\u52a8\u4f5c\u3002\u5982\u679c\u4e0d\u4f7f\u7528\u8bbe\u8ba1\u6a21\u5f0f\uff0c\u6211\u4eec\u7684\u4ee3\u7801\u53ef\u80fd\u662f\u8fd9\u6837\uff1a<\/p>\n

[code lang=”java”]<\/p>\n

class Fan {<\/p>\n

\t\/**
\n\t *
\n\t * @param level \u8868\u793a\u6863\u4f4d
\n\t *\/
\n\tpublic void rotate(int level){
\n\t\tif(level==1){
\n\t\t\tSystem.out.println("rotate at low speed");
\n\t\t}
\n\t\telse if(level==2){
\n\t\t\tSystem.out.println("rotate at intermediate speed");
\n\t\t}
\n\t\telse if(level==3){
\n\t\t\tSystem.out.println("rotate at high speed");
\n\t\t}
\n\t}
\n}<\/p>\n

[\/code]<\/p>\n

\u5047\u5982\u7535\u6247\u65b0\u589e\u52a01\u6863\uff0c\u5fc5\u987b\u8981\u4fee\u6539rotate\u65b9\u6cd5\uff0c\u8fd9\u6837\u5c31\u8fdd\u53cd\u4e86\u5f00\u95ed\u539f\u5219\u3002\u8fd9\u65f6\u5019\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u4f7f\u7528\u72b6\u6001\u6a21\u5f0f\u3002\u72b6\u6001\u6a21\u5f0f\u7684\u610f\u601d\u662f\uff1a\u6211\u4eec\u5c06\u5bf9\u8c61\u7684\u67d0\u4e2a\u52a8\u4f5c\u59d4\u6258\u7ed9\u67d0\u4e2a\u5177\u4f53\u7684\u72b6\u6001\u3002\u901a\u5e38\uff0c\u6211\u4eec\u6709\u4e00\u4e2a\u72b6\u6001\u7684\u63a5\u53e3\uff0c\u8fd9\u4e2a\u63a5\u53e3\u4e0b\u6709\u591a\u4e2a\u5177\u4f53\u7684\u5b9e\u73b0\u7c7b\u3002\u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u91cc\uff0c\u6863\u4f4d(\u4e0b\u9762\u7684\u4ee3\u7801\u91cc\u7528Level\u8868\u793a)\u5c31\u662f\u4e00\u4e2a\u63a5\u53e3\uff0c1\u6863\uff0c2\u6863\uff0c3\u6863\u662f\u5177\u4f53\u7684\u5b9e\u73b0\u7c7b\u3002\u4e0b\u9762\u662f\u4f7f\u7528\u72b6\u6001\u6a21\u5f0f\u540e\u7684\u4ee3\u7801\uff1a<\/p>\n

[code lang=”java”]<\/p>\n

interface Level{
\n\tpublic void rotate();
\n}<\/p>\n

class Level1 implements Level {<\/p>\n

\tpublic void rotate() {
\n\t\tSystem.out.println("rotate at low speed");
\n\t}<\/p>\n

}<\/p>\n

class Level2 implements Level {<\/p>\n

\tpublic void rotate() {
\n\t\tSystem.out.println("rotate at intermediate speed");
\n\t}<\/p>\n

}<\/p>\n

class Level3 implements Level {<\/p>\n

\tpublic void rotate() {
\n\t\tSystem.out.println("rotate at high speed");
\n\t}<\/p>\n

}<\/p>\n

class Fan {<\/p>\n

\tprivate Level level;<\/p>\n

\tpublic Fan(Level level){
\n\t\tthis.level = level;
\n\t}<\/p>\n

\tpublic Level getLevel() {
\n\t\treturn level;
\n\t}<\/p>\n

\tpublic void setLevel(Level level) {
\n\t\tthis.level = level;
\n\t}<\/p>\n

\tpublic void rotate(){
\n\t\tlevel.rotate();
\n\t}<\/p>\n

}<\/p>\n

public class StatePatternDemo {<\/p>\n

\tpublic static void main(String[] args) {
\n\t\tLevel level = new Level1();
\n\t\tFan fan = new Fan(level);
\n\t\tfan.rotate();<\/p>\n

\t\tfan.setLevel(new Level2());
\n\t\tfan.rotate();<\/p>\n

\t\tfan.setLevel(new Level3());
\n\t\tfan.rotate();
\n\t}<\/p>\n

}<\/p>\n

[\/code]<\/p>\n

\u8f93\u51fa\u5982\u4e0b:
\nrotate at low speed
\nrotate at intermediate speed
\nrotate at high speed<\/p>\n

\u4ece\u4e0a\u9762\u7684\u4ee3\u7801\u53ef\u4ee5\u770b\u51fa\uff1a\u6211\u4eec\u5c06\u7535\u6247\u7684rotate\u884c\u4e3a\u59d4\u6258\u7ed9\u5177\u4f53\u7684level\u5bf9\u8c61\u3002\u5f53\u65b0\u589e\u52a0\u4e00\u4e2a\u6863\u4f4d\u65f6\uff0c\u6211\u4eec\u53ea\u9700\u8981\u65b0\u589e\u4e00\u4e2a\u5177\u4f53\u7684Level\u7c7b\u5c31\u53ef\u4ee5\u4e86\u3002\u8fd9\u6837\u4e5f\u7b26\u5408\u4e86\u5f00\u95ed\u539f\u5219\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

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