PHP设计模式

PHP常见设计模式主要有：工厂模式、单例模式

1、工厂模式

<?php
abstract class DB{
    abstract public function select();
    abstract public function update();
    abstract public function delete();
    abstract public function add();
}
class MysqlFactory extends DB{
    public function select() {
        echo 'mysql select';
    }
    public function update(){
        echo 'mysql update';
    }
    public function delete(){
        echo 'mysql delete';
    }
    public function add(){
        echo 'mysql add';
    }
}
class SqlserverFactory extends DB{
    public function select() {
        echo 'SqlServer select';
    }
    public function update(){
        echo 'SqlServer update';
    }
    public function delete(){
        echo 'SqlServer delete';
    }
    public function add(){
        echo 'SqlServer add';
    }
}
class Factory{
    public static function createFactory($dbname){
        $dbname = ucwords($dbname) . 'Factory';
        return new $dbname();
    }
}
$db = Factory::createFactory('sqlserver');
$db->select();

2、单例模式

class DB{
    public static $instance = null;
    public static function getInstance(){
        if(self::$instance == null){
            self::$instance = new self();
        }
        return self::$instance;
    }
}

3、单例模式与工厂模式相结合

<?php
abstract class DB{
    abstract public function getInstance();
    abstract public function select();
    abstract public function update();
    abstract public function delete();
    abstract public function add();
}
class MysqlFactory extends DB{
    public static $instance = null;
    public function getInstance(){
        if(self::$instance == null){
            self::$instance = new self();
        }
        return self::$instance;
    }
    public function select() {
        echo 'mysql select';
    }
    public function update(){
        echo 'mysql update';
    }
    public function delete(){
        echo 'mysql delete';
    }
    public function add(){
        echo 'mysql add';
    }
}
class SqlserverFactory extends DB{
    public static $instance = null;
    public function getInstance(){
        if(self::$instance == null){
            self::$instance = new self();
        }
        return self::$instance;
    }
    public function select() {
        echo 'SqlServer select';
    }
    public function update(){
        echo 'SqlServer update';
    }
    public function delete(){
        echo 'SqlServer delete';
    }
    public function add(){
        echo 'SqlServer add';
    }
}
class Factory{
    public static function createFactory($dbname){
        $dbname = ucwords($dbname) . 'Factory';
        return $dbname::getInstance();
    }
}
$db = Factory::createFactory('sqlserver');
$db->select();

是不是感觉很有意思呀！

在框架中基本上这些模式都会被用到