PHP错误与异常处理(四)

set_execption_handler

set_exception_handler ( callable $exception_handler )

设置默认的异常处理程序，用于没有用 try/catch 块来捕获的异常。 在exception_handler 调用后异常会中止。

代码如下:

<?php

header('content-type:text/html;charset=utf-8'); 
class ExceptionRedirectHandler{
       protected $_exception;
       public $redirect = '404/index.html';//自己网上下载的404页面路径 
       public $file = 'E:\php39\impover\redirect.log';//保存的日志的位置
       private $_msg='';
       public function __construct(Exception $e){
           $this->_exception = $e;
       }
 
    
     public static function handle(Exception $e){ 
         $self = new self($e);
         $self->log();
         while(@ob_end_clean());//清除缓存
         header('HTTP/1.1 307 Temporary Redirect');//307重定向
         header('Cache-Control:no-cache,must-revalidate');//不缓存 
         header('refresh:1;url='.$self->redirect);
         exit(); 
      }
 
 
     
    public function log(){
           //写入日志
           $this->_msg =<<<EOF
异常信息为:{$this->_exception->getMessage()}
异常文件为:{$this->_exception->getFile()}
异常行号为:{$this->_exception->getLine()}
EOF;
          error_log($this->_msg,3,$this->file);
      } 
  } 

set_exception_handler(array('ExceptionRedirectHandler','handle'));
 
$link = new pdo('mysql:host=localhost;dbname=t_test','root','cuowu');

 if (!$link) {
     throw new Exception('数据库连接失败，请查询原因');
 }
  
?>

得到的结果是数据库连接错误，跳转到了如下页面:

image.png

附: PHP中Header使用的HTTP协议(如需常用，可以把它封装成一个函数，放数组中)以及常用的header头设置:

100 => "HTTP/1.1 100 Continue",

101 => "HTTP/1.1 101 Switching Protocols",

200 => "HTTP/1.1 200 OK", ///200 正常状态

201 => "HTTP/1.1 201 Created",

202 => "HTTP/1.1 202 Accepted",

203 => "HTTP/1.1 203 Non-Authoritative Information",

204 => "HTTP/1.1 204 No Content",

205 => "HTTP/1.1 205 Reset Content",

206 => "HTTP/1.1 206 Partial Content",

300 => "HTTP/1.1 300 Multiple Choices",

301 => "HTTP/1.1 301 Moved Permanently",

302 => "HTTP/1.1 302 Found",

303 => "HTTP/1.1 303 See Other",

304 => "HTTP/1.1 304 Not Modified",

305 => "HTTP/1.1 305 Use Proxy",

307 => "HTTP/1.1 307 Temporary Redirect",

400 => "HTTP/1.1 400 Bad Request",

401 => "HTTP/1.1 401 Unauthorized",

402 => "HTTP/1.1 402 Payment Required",

403 => "HTTP/1.1 403 Forbidden",

404 => "HTTP/1.1 404 Not Found",

405 => "HTTP/1.1 405 Method Not Allowed",

406 => "HTTP/1.1 406 Not Acceptable",

407 => "HTTP/1.1 407 Proxy Authentication Required",

408 => "HTTP/1.1 408 Request Time-out",

409 => "HTTP/1.1 409 Conflict",

410 => "HTTP/1.1 410 Gone",

411 => "HTTP/1.1 411 Length Required",

412 => "HTTP/1.1 412 Precondition Failed",

413 => "HTTP/1.1 413 Request Entity Too Large",

414 => "HTTP/1.1 414 Request-URI Too Large",

415 => "HTTP/1.1 415 Unsupported Media Type",

416 => "HTTP/1.1 416 Requested range not satisfiable",

417 => "HTTP/1.1 417 Expectation Failed",

500 => "HTTP/1.1 500 Internal Server Error",

501 => "HTTP/1.1 501 Not Implemented",

502 => "HTTP/1.1 502 Bad Gateway",

503 => "HTTP/1.1 503 Service Unavailable",

504 => "HTTP/1.1 504 Gateway Time-out"

header('Content-language: en'); //设置上下文语言

// 设置页面最后修改时间（多用于防缓存）

$time = time() - 60; //建议使用filetime函数来设置页面缓存时间

header('Last-Modified: '.gmdate('D, d M Y H:i:s', $time).' GMT');

// 设置头文件类型，可以用于流文件或者文件下载 header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename="example.zip"');
header('Content-Transfer-Encoding: binary');
readfile('example.zip');//读取文件到客户端

//禁用页面缓存 header('Cache-Control: no-cache, no-store, max-age=0, must-revalidate');
header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');
header('Pragma: no-cache');

//设置页面头信息 header('Content-Type: text/html; charset=iso-8859-1');
header('Content-Type: text/html; charset=utf-8');
header('Content-Type: text/plain');
header('Content-Type: image/jpeg');
header('Content-Type: application/zip');
header('Content-Type: application/pdf');
header('Content-Type: audio/mpeg');
header('Content-Type: application/x-shockwave-flash');
//....至于Content-Type 的值 可以去查查 w3c 的文档库，那里很丰富