php的设计模式

简单工厂

<?php
interface db{
    function conn();
}
class dbMysql implements db{
    public function conn(){
        echo '连接上mysql';
    }
}

class dbSqlite implements db{
    public function conn(){
        echo '连接上sqlite';
    }
}

// 简单工厂
class Factory {
    public static function createDb($type = ''){
        if($type == 'mysql'){
            return new dbMysql();
        }else if($type == 'sqlite'){
            return new dbSqlite();
        }else{
            throw new Exception("Error db type", 1);
        }
    }
}

// 只对外开放一个Factory::createDb()方法
$mysql =  Factory::createDb('mysql');
$mysql->conn();
// 如果要新增数据库类型？还要去改代码，如果是java语言改完还要编译，这有多么麻烦
// 在面向对象设计法则中，有一个开闭原则，对于修改是封闭，对于扩展是开放的。

工厂模式

<?php
interface db{
    function conn();
}
interface factory{
    function createDb();
}
class dbMysql implements db{
    public function conn(){
        echo '连接上mysql';
    }
}

class dbSqlite implements db{
    public function conn(){
        echo '连接上sqlite';
    }
}

class mysqlFactory implements factory{
    public function createDb(){
        return new dbMysql();
    }
}

class sqliteFactory implements factory{
    public function createDb(){
        return new dbSqlite();
    }
}

$fact = new mysqlFactory();
$db = $fact->createDb();
$db->conn();

单例模式

<?php
class Single{
    protected static $ins = null;
    public static function getIns() {
        if(self::$ins === null) {
            self::$ins = new self();
        }
        return self::$ins;
    }
    // 方法 + final 不能被覆盖  class + final 不能被继承
    final protected function __construct() {}
    final protected function __clone() {}
}

$s1 = Single::getIns();
$s2 = clone $s1;
if($s1 === $s2){
    echo '是同一个对象';
}else{
    echo '不是同一个对象';
}

 观察者模式

<?php
// php5中提供观察者模式observer与被观察者subject的接口


class User implements SplSubject{
    public $login_num;
    public $observers = null;
    public $hobby;
    public function __construct(){
        $this->login_num = rand(1, 10);
        $hobbys = ['running', 'shopping', 'supprot', 'study'];
        shuffle($hobbys);
        $this->hobby = $hobbys[0];
        $this->observers =  new SplObjectStorage();
    }

    public function login(){
        echo 'login success';
        echo '<br>';
        $this->notify();
    }

    public function attach(SPLObserver $observer){
        $this->observers->attach($observer);
    }

    public function detach(SPLObserver $observer){
        $this->observers->detach($observer);
    }

    public function notify(){
        $this->observers->rewind();
        while ($this->observers->valid()) {
            $observer = $this->observers->current();
            $observer->update($this);
            $this->observers->next();
        }
    }
}

class safety implements SPLObserver{
    public function update(SplSubject $subject){
        if($subject->login_num > 3){
            echo '您频繁登陆，是否有难言之隐？'.'<br>';
        }
    }
}


class ad implements SPLObserver{
    public function update(SplSubject $subject){
        switch ($subject->hobby) {
            case 'running':
                echo 'addidas运动裤大折扣';
                break;
            case 'shopping':
                echo '沃尔玛今日促销';
                break;
            case 'supprot':
                echo 'NBA总决赛明天开始';
                break;
            case 'study':
                echo '学习文具优惠';
                break;
            default:
                # code...
                break;
        }
    }
}

$user = new User();
$user->attach(new safety());
$user->attach(new ad());
$user->login();

责任链模式

<?php
// 责任链模式


class Brand{
    private $power = 1;
    private $higher = 'Admin';

    public function process($lev){
        if($lev <= $this->power){
            echo '版主删帖';
        }else{
            $higer = new $this->higher;
            $higer->process($lev);
        }
    }
}


class Admin{
    private $power = 2;
    private $higher = 'Proclie';
    public function process($lev){
        if($lev >= $this->power){
            echo '封号处理';
        }else{
            $higer = new $this->higher;
            $higer->process($lev);
        }
    }
}


class Proclie{
    public function process(){
        echo '请你喝茶';
    }
}


$dange_lever = 2;
$judege = new Brand();
$judege->process($dange_lever);

策略模式

<?php

interface math{
    function calc($first, $last);
}

class Add implements math{
    public function calc($first, $last){
        return $first + $last;
    }
}


class Sub implements math{
    public function calc($first, $last){
        return $first - $last;
    }
}


class Mul implements math{
    public function calc($first, $last){
        return $first * $last;
    }
}

class Div implements math{
    public function calc($first, $last){
        return $first / $last;
    }
}


// 虚拟计算器
class CMath{
    protected $calc = null;
    function __construct($calc){
        $this->calc = new $calc;
    }
    public function calc($first, $last){
        return $this->calc->calc($first, $last);
    }
}

$cmath = new CMath('Sub');
echo $cmath->calc(3, 2);

 适配器模式

<?php
// 服务端
class Weather{
    public static function show(){
        $today = ['tep' => 28, 'wind' => 7, 'sun' => 'sunny'];
        return serialize($today);
    }
}

// 增加一个适配器
class AdapterWeather extends Weather{
    public static function show(){
        $today = parent::show();
        $today = json_encode(unserialize($today));
        return $today;
    }
}

// 客户端
$data = unserialize(Weather::show());
echo '今天温度'.$data['tep'].'度'.',天气:'.$data['sun'].'<br>';

// 如果一个android端，访问这个接口，但是不认识php串行字符串，还要去改服务端改为返回json格式，而且还要顺便客户端也要顺便改，这样子很麻烦，我们可以使用适配器模式


// 假设 java客户端
$data = json_decode(AdapterWeather::show(),true);
echo '今天温度'.$data['tep'].'度'.',天气:'.$data['sun'].'<br>';

 桥接模式

<?php
abstract class Info{
    // 发射器
    protected $send = null;

    public function __construct($send){
        $this->send = $send;
    }

    abstract public function msg($content);

    public function send($to, $content){
        $content = $this->msg($content);
        $this->send->send($to, $content);
    }
}

class zn{
    public function send($to, $content){
        echo 'zn站内给'.$to.'内容是'.$content;
    }
}


class sms{
    public function send($to, $content){
        echo 'sms站内给'.$to.'内容是'.$content;
    }
}



class email{
    public function send($to, $content){
        echo 'email站内给'.$to.'内容是'.$content;
    }
}

class commoninfo extends Info{
    public function msg($content){
        return '普通信息：'.$content;
    }
}

class warninfo extends Info{
    public function msg($content){
        return '紧急信息：'.$content;
    }
}

class dangeinfo extends Info{
    public function msg($content){
        return '特急信息：'.$content;
    }
}

$commoninfo = new commoninfo(new zn());
$commoninfo->send('小明','吃鸡了');

 装饰模式

<?php
// 装饰器模式做文章修饰功能
class BaseArt {
    protected $content;
    protected $art;

    public function __construct($content) {
        $this->content = $content;
    }

    public function decorator(){
        return $this->content;
    }
}

class BianArt extends BaseArt{

    public function __construct($art) {
        $this->art = $art;
        $this->decorator();
    }

    public function decorator() {
        return $this->content = $this->art->decorator(). '小编摘要';
    }
}

class SeonArt extends BaseArt{

    public function __construct($art) {
        $this->art = $art;
        $this->decorator();
    }
    public function decorator() {
        return $this->content = $this->art->decorator(). '加上seo关键词';
    }
}


$ba = new SeonArt(new BianArt(new BaseArt('天天向上')));
echo $ba->decorator();