Exception::getPrevious

(PHP 5 >= 5.3.0)

Exception::getPrevious — 返回异常链中的前一个异常

说明

final public Exception Exception::getPrevious ( void )

返回异常链中的前一个异常（ Exception::__construct() 方法的第三个参数）。

参数

此函数没有参数。

返回值

返回异常链中的前一个异常Exception，否则返回 NULL 。

范例

Example #1 Exception::getPrevious() 示例

追踪异常，并循环打印。

  <?php
 class  MyCustomException  extends  Exception  {}

function  doStuff () {
    try {
        throw new  InvalidArgumentException ( "You are doing it wrong!" ,  112 );
    } catch( Exception $e ) {
        throw new  MyCustomException ( "Something happend" ,  911 ,  $e );
    }
}


try {
     doStuff ();
} catch( Exception $e ) {
    do {
         printf ( "%s:%d %s (%d) [%s]\n" ,  $e -> getFile (),  $e -> getLine (),  $e -> getMessage (),  $e -> getCode (),  get_class ( $e ));
    } while( $e  =  $e -> getPrevious ());
}
 ?>

以上例程的输出类似于：

/home/bjori/ex.php:8 Something happend (911) [MyCustomException]
/home/bjori/ex.php:6 You are doing it wrong! (112) [InvalidArgumentException]

用户评论:

[#1] Anonymous [2011-10-03 13:11:11]

May be I am late (5.2 is not supported). But if you want use the functionality of "previous Exception" in PHP < 5.3 or write compatible code, you can use next way as below.

<?php abstract class App_Exception_PreviousNativeAbstract extends Exception { public static $printPrevious = true; public function __toString() { $result = array(); $result[] = sprintf("Exception '%s' with message '(%s) %s' in %s:%d", get_class($this), $this->code, $this->message, $this->file, $this->line); $result[] = '---[Stack trace]:'; $result[] = $this->getTraceAsString(); if (self::$printPrevious) { $previous = $this->getPrevious(); if ($previous) { do { $result[] = '---[Previous exception]:'; $result[] = sprintf("Exception '%s' with message '(%s) %s' in %s:%d", get_class($previous), $previous->getCode(), $previous->getMessage(), $previous->getFile(), $previous->getLine()); $result[] = '---[Stack trace]:'; $result[] = $previous->getTraceAsString(); } while(method_exists($previous, 'getPrevious') && ($previous = $previous->getPrevious())); } } return implode("\r\n", $result); } } abstract class App_Exception_PreviousLegacyAbstract extends App_Exception_PreviousNativeAbstract { protected $previous; public function __construct($message, $code = 0, Exception $previous = null) { $this->previous = $previous; parent::__construct($message, $code); } public function getPrevious() { return $this->previous; } } if (version_compare(PHP_VERSION, '5.3.0', '>=')) { abstract class App_Exception_PreviousAbstract extends App_Exception_PreviousNativeAbstract {} } else { abstract class App_Exception_PreviousAbstract extends App_Exception_PreviousLegacyAbstract {} } class App_Exception extends App_Exception_PreviousAbstract { public function __construct($message, $code = 0, Exception $previous = null) { parent::__construct($message, 0, $previous); } } // Example: try { // ... throw new Exception('Exception mesage'); // ... } catch (Exception $e) { throw new App_Exception('App exception mesage', 0, $e); } ?>