php设计模式责任链模式

Posted 2022-01-27 itsuibi

  责任链模式为请求创建了一个接收者对象的链。这种模式给予请求的类型，对请求的发送者和接收者进行解耦。这种类型的设计模式属于行为型模式。

  在这种模式中，通常每个接收者都包含对另一个接收者的引用。如果一个对象不能处理该请求，那么它会把相同的请求传给下一个接收者，依此类推。

<?php
define("WARNING_LEVEL", 1);
define("DEBUG_LEVEL", 2);
define("ERROR_LEVEL", 3);

abstract class AbstractLog
    protected $level;
    protected $nextlogger;

    public function __construct($level)
        $this->level = $level;
    

    public function setNextLogger($next_logger)
        $this->nextlogger = $next_logger;
    

    public function logMessage($level,$message)
        if($this->level == $level)
            $this->write($message);
        

        if($this->nextlogger)
            $this->nextlogger->logMessage($level,$message);
        
    

    abstract function write($message);


class DebuggLogger extends AbstractLog
    public function write($message)
        echo "Debug info: $message \n";
    


class WarningLogger extends AbstractLog
    public function write($message)
        echo "Warning info: $message \n";
    


class ErrorLogger extends AbstractLog
    public function write($message)
        echo "Error info: $message \n";
    


function getChainOfLoggers()
    $warning = new WarningLogger(WARNING_LEVEL);
    $debugg = new DebuggLogger(DEBUG_LEVEL);
    $error = new ErrorLogger(ERROR_LEVEL);

    $warning->setNextLogger($debugg);
    $debugg->setNextLogger($error);

    return $warning;


$chain = getChainOfLoggers();

$chain->logMessage(WARNING_LEVEL,"这是一条警告");
$chain->logMessage(DEBUG_LEVEL,"这是一条Debug");
$chain->logMessage(ERROR_LEVEL,"这是一条致命错误");

输出

Warning info: 这是一条警告
Debug info: 这是一条Debug
Error info: 这是一条致命错误