PHP errors and exceptions notes and summaries (16) custom Exception handlers

You can use the custom exception handler to handle all uncaught exceptions (exceptions that are not caught with Try/catch).

Set_exception_handler (): Sets a user-defined exception handler that, when an uncaught exception occurs, the name of the function that is called (the callback function), which must be called in the

Set_exception_handler () has been defined before. The handler needs to accept a parameter, which is a thrown exception object

Cases

1<?PHP2 Header(' content-type:text/html; Charset=utf-8 ');3 Header(' content-type:text/html; Charset=utf-8 ');4 functionExceptionhandler_1 ($e){5     Echo' Custom Exception Processor 1 ';6     Echo' Exception information: '.$e-getMessage ();7 }8 9 functionExceptionhandler_2 ($e){Ten     Echo' Custom Exception Processor 2 '; One     Echo' Exception information: '.$e-getMessage (); A } -  - Throw New Exception(' Test ');

Post-run output:

Fatal error: The exception "Exception" was not caught. You can use the Set_exception_hanlder () method when an uncaught exception occurs:

1<?PHP2 Header(' content-type:text/html; Charset=utf-8 ');3 Header(' content-type:text/html; Charset=utf-8 ');4 functionExceptionhandler_1 ($e){5     Echo' Custom Exception Processor 1 ',__function__, ' <br> ';6     Echo' Exception information: '.$e-getMessage ();7 }8 9 functionExceptionhandler_2 ($e){Ten     Echo' Custom Exception Processor 2 ',__function__, ' <br> '; One     Echo' Exception information: '.$e-getMessage (); A } -  - set_exception_handler (' exceptionhandler_1 '); the Throw New Exception(' Test ');

Post-run output:

The previous example uses a custom exception handler to handle an uncaught exception.

Example 2 when more than one Set_exception_handler () method is defined, the last method overwrites the previous method, while using Restore_exception_handler () reverts to the last defined custom handler function.

1<?PHP2 Header(' content-type:text/html; Charset=utf-8 ');3 Header(' content-type:text/html; Charset=utf-8 ');4 functionExceptionhandler_1 ($e){5     Echo' Custom Exception Processor 1 ',__function__, ' <br> ';6     Echo' Exception information: '.$e-getMessage ();7 }8 9 functionExceptionhandler_2 ($e){Ten     Echo' Custom Exception Processor 2 ',__function__, ' <br> '; One     Echo' Exception information: '.$e-getMessage (); A } -  - Set_exception_handler(' exceptionhandler_1 '); the Set_exception_handler(' exceptionhandler_2 '); - Throw New Exception(' Test ');

Output:

1<?PHP2 Header(' content-type:text/html; Charset=utf-8 ');3 Header(' content-type:text/html; Charset=utf-8 ');4 functionExceptionhandler_1 ($e){5     Echo' Custom Exception Processor 1 ',__function__, ' <br> ';6     Echo' Exception information: '.$e-getMessage ();7 }8 9 functionExceptionhandler_2 ($e){Ten     Echo' Custom Exception Processor 2 ',__function__, ' <br> '; One     Echo' Exception information: '.$e-getMessage (); A } -  - Set_exception_handler(' exceptionhandler_1 '); the Set_exception_handler(' exceptionhandler_2 '); - Restore_exception_handler (); - Throw New Exception(' Test ');

Output:

After using a custom exception handler, the program does not continue to execute down:

1<?PHP2 Header(' content-type:text/html; Charset=utf-8 ');3 Header(' content-type:text/html; Charset=utf-8 ');4 functionExceptionhandler_1 ($e){5     Echo' Custom Exception Processor 1 ',__function__, ' <br> ';6     Echo' Exception information: '.$e-getMessage ();7 }8 9 functionExceptionhandler_2 ($e){Ten     Echo' Custom Exception Processor 2 ',__function__, ' <br> '; One     Echo' Exception information: '.$e-getMessage (); A } -  - Set_exception_handler(' exceptionhandler_1 '); the Throw New Exception(' Test '); -  - Echo' Continue ... ';

Output:

These are custom exception handlers to handle uncaught exceptions, and you can also use custom exception handling classes to handle uncaught exceptions

1<?PHP2 classexceptionhandler{3     protected $_exception;4     protected $_logfile= ' D:/practise/php/error/logexception2.log ';5      Public function__construct (Exception $e){6         //Save Exception Object7         $this->_exception =$e;8     }9 Ten      Public Static functionHandleException $e){ One         $self=NewSelf$e); A         $self-Log(); -         Echo $self; -     } the  -     //Logging Method -      Public function Log(){ -         Error_log($this->_exception->getmessage ().Php_eol, 3,$this-_logfile); +     } -  +      Public function__tostring () { A         $message= <<<EOF at<! DOCTYPE html> - - -<meta charset= "UTF-8" > -<title>Document</title> - in<body> - to<p> Contact your Administrator </p> +</body> - the EOF; *     return $message; $     }Panax Notoginseng } -  the  + Set_exception_handler(Array(' Exceptionhandler ', ' handle '));//handles an uncaught exception. First parameter class name, second parameter method name A //Test the Throw New Exception("Test a custom exception handler");

Output:

File LogException2.log:

PHP errors and exceptions notes and summaries (16) custom Exception handlers