Exception::getPrevious

(PHP 5 >= 5.3.0, PHP 7, PHP 8)

Exception::getPrevious返回异常链中的前一个异常

说明

final public Exception::getPrevious ( ) : Throwable

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 Throwable,否则返回null

更新日志

版本 说明
7.0.0 返回类型的定义改成了 Throwable

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]

参见

User Contributed Notes

harry at upmind dot com 10-Nov-2018 03:03
/**
     * Gets sequential array of all previously-chained errors
     *
     * @param Throwable $error
     *
     * @return Throwable[]
     */
    function getChain(Throwable $error) : array
    {
        $chain = [];

        do {
            $chain[] = $error;
        } while ($error = $error->getPrevious());

        return $chain;
    }
Anonymous 03-Oct-2011 01:11
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);
}
?>
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