php自定义异常处理

Question

I am wanting to handle exceptions in my PHP application myself.

When I throw an exception I am wanting to pass along a title to be used in the error page.

Can someone please link me to a good tutorial, or write a clear explanation of how the exception handling actually works (eg how to know what sort of exception you are dealing with, etc.

Answer 1

Official docs is a good place to start - http://php.net/manual/en/language.exceptions.php.

If it is just a message that you want to capture you would do it at follows;

try{
    throw new Exception("This is your error message");
}catch(Exception $e){
    print $e->getMessage();
}

If you want to capture specific errors you would use:

try{
    throw new SQLException("SQL error message");
}catch(SQLException $e){
    print "SQL Error: ".$e->getMessage();
}catch(Exception $e){
    print "Error: ".$e->getMessage();
}

For the record - you'd need to define SQLException. This can be done as simply as:

class SQLException extends Exception{

}

---

For a title and message you would extend the Exception class:

class CustomException extends Exception{

    protected $title;

    public function __construct($title, $message, $code = 0, Exception $previous = null) {

        $this->title = $title;

        parent::__construct($message, $code, $previous);

    }

    public function getTitle(){
        return $this->title;
    }

}

You could invoke this using :

try{
    throw new CustomException("My Title", "My error message");
}catch(CustomException $e){
    print $e->getTitle()."<br />".$e->getMessage();
}