PHP 抛出异常与报错的处理

• laravel学院-最佳实践系列（十一）：深入探讨 PHP 错误异常处理机制及 Laravel 框架底层的相应实现
• set_exception_handler

在使用 laravel 框架(或者其他框架)的时候，我们都知道在抛出异常报错的时候，其实这个异常并不像我们平时使用 throw new Exception('程序异常'); 抛出的页面那么难看，另外，在抛出异常后，框架会做异常日志记录。

• 切记，在执行完毕 set_exception_handler后，记得使用 restore_exception_handler 函数将异常处理还原

<?php
// 注册全局异常处理程序
set_exception_handler(function (Exception $e) {
   // 处理并记录异常
});

// 注册其他的异常处理程序...

// 还原成之前的全局异常处理程序
restore_exception_handler();

demo-注意行号 打印结果

• 注意
  所有的报错类都是集成 Exception 类的。所以，你如果需要打印错误信息，行号等信息，是可以直接调用 public 方法的。我在 demo 中是打印的报错对象
  在实际应用中，我们可以根据是否已经打开 debug 等配置，来决定怎么处理报错，并且可以在抛出报错之前可以将报错存入日志

class Exception implements Throwable {
    protected $message;
    protected $code;
    protected $file;
    protected $line;


    /**
     * Clone the exception
     * Tries to clone the Exception, which results in Fatal error.
     * @link https://php.net/manual/en/exception.clone.php
     * @return void
     * @since 5.1.0
     */
    final private function __clone() { }

    /**
     * Construct the exception. Note: The message is NOT binary safe.
     * @link https://php.net/manual/en/exception.construct.php
     * @param string $message [optional] The Exception message to throw.
     * @param int $code [optional] The Exception code.
     * @param Throwable $previous [optional] The previous throwable used for the exception chaining.
     * @since 5.1.0
     */
    public function __construct($message = "", $code = 0, Throwable $previous = null) { }

    /**
     * Gets the Exception message
     * @link https://php.net/manual/en/exception.getmessage.php
     * @return string the Exception message as a string.
     * @since 5.1.0
     */
    final public function getMessage() { }

    /**
     * Gets the Exception code
     * @link https://php.net/manual/en/exception.getcode.php
     * @return mixed|int the exception code as integer in
     * <b>Exception</b> but possibly as other type in
     * <b>Exception</b> descendants (for example as
     * string in <b>PDOException</b>).
     * @since 5.1.0
     */
    final public function getCode() { }

    /**
     * Gets the file in which the exception occurred
     * @link https://php.net/manual/en/exception.getfile.php
     * @return string the filename in which the exception was created.
     * @since 5.1.0
     */
    final public function getFile() { }

    /**
     * Gets the line in which the exception occurred
     * @link https://php.net/manual/en/exception.getline.php
     * @return int the line number where the exception was created.
     * @since 5.1.0
     */
    final public function getLine() { }

    /**
     * Gets the stack trace
     * @link https://php.net/manual/en/exception.gettrace.php
     * @return array the Exception stack trace as an array.
     * @since 5.1.0
     */
    final public function getTrace() { }

    /**
     * Returns previous Exception
     * @link https://php.net/manual/en/exception.getprevious.php
     * @return Exception the previous <b>Exception</b> if available
     * or null otherwise.
     * @since 5.3.0
     */
    final public function getPrevious() { }

    /**
     * Gets the stack trace as a string
     * @link https://php.net/manual/en/exception.gettraceasstring.php
     * @return string the Exception stack trace as a string.
     * @since 5.1.0
     */
    final public function getTraceAsString() { }

    /**
     * String representation of the exception
     * @link https://php.net/manual/en/exception.tostring.php
     * @return string the string representation of the exception.
     * @since 5.1.0
     */
    public function __toString() { }

    public function __wakeup() { }
}

---

报错处理

• 菜鸟手册-PHP set_error_handler() 函数

<?php

set_error_handler(//error handler function
    function ($errno, $errstr, $errfile, $errline) {
        echo "错误编号: $errno<br>";
        echo "错误信息: $errstr<br>";
        echo "出错文件: $errfile<br>";
        echo "出错行号: $errline<br>";
        die;
    });

echo $arr[1];

image.png image.png