Exception::getPrevious

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

Exception::getPrevious — 返回前一个 Throwable

说明

final public Exception::getPrevious(): ?Throwable

返回前一个 Throwable （传递给 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。

范例

示例 #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

Throwable::getPrevious() - 返回先前的 Throwable

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User Contributed Notes 2 notes

down

harry at upmind dot com ¶

3 years ago


/**
     * 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;
    }

down

-6

Anonymous ¶

10 years ago


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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