责任链模式：使多个对象都有机会处理请求，从而避免请求的发送者和接收者之间的耦合关系。将这些对象连成一条链，并沿着这条链传递该请求，直到有一个对象处理它为止。
示例图：
php代码示例：
<?php
class Request{
public $tcontent,$tnum;
function __construct($tcontent,$tnum){
$this -> tcontent = $tcontent;
$this -> tnum = $tnum;
}
}
class Manager{
public $name,$manager;
function __construct($temp){
$this -> name = $temp;
}
function SetSuccessor($temp){
$this -> manager = $temp;
}
function GetRequest($req){
}
}
class CommonManager extends Manager{
function GetRequest($req){
if($req -> tnum >= 0 && $req -> tnum < 10){
print $this->name." handled ".$req->tnum." request\n";
}else{
$this -> manager -> GetRequest($req);
}
}
}
class MajorDomo extends Manager{
function GetRequest($req){
if($req -> tnum >= 10){
print $this->name." handled ".$req->tnum." request\n";
}
}
}
$common = new CommonManager("xiao");
$major = new MajorDomo("da");
$common -> SetSuccessor($major);
$req2 = new Request("salary",3);
$common -> GetRequest($req2);
$req1 = new Request("vacation",33);
$common -> GetRequest($req1);
?>
原文：http://www.cnblogs.com/zhutianpeng/p/4232163.html