自己创建一个Rest API

2015.10 大三上 面向web的计算课程

在大三上的课程中，海涛老师要求项目中运用rest进行数据采集。我两眼懵逼，啥是rest呀？然后就去网上找了学习资料。然后之后就着手开始自己写一个rest api。为什么要自己写呢？因为我没用框架，第一次使用php做网站，我想先打好基础再考虑高层次的东西，就没有用框架。其他人用的诸如laravel之类的PHP框架自己本身会带rest机制。对于我一个没用框架的孩子，只能自己默默写了。

当然，有参考例子哦http://www.gen-x-design.com/archives/create-a-rest-api-with-php/，不过这个例子一点都不全面，我自己补充了很多。

<?php


class RestUtils
{
 public static function processRequest()
    {
        // get our verb
        $request_method = strtolower($_SERVER['REQUEST_METHOD']);
        $return_obj     = new RestRequest();
        // we'll store our data here
        $data           = array();
    
        switch ($request_method)
        {
            // gets are easy...
            case 'get':
                $data = $_GET;
                break;
                // so are posts
            case 'post':
                $data = $_POST;
                break;
                // here's the tricky bit...
            case 'put':
            case 'delete':
                // basically, we read a string from PHP's special input location,
                // and then parse it out into an array via parse_str... per the PHP docs:
                // Parses str  as if it were the query string passed via a URL and sets
                // variables in the current scope.
                $string=file_get_contents('php://input');
                preg_match_all("|\".*\"|",$string,$out1, PREG_PATTERN_ORDER);
                preg_match_all("|\"\s+.*\s+------|",$string,$out2, PREG_PATTERN_ORDER);
                for($i=0;$i<count($out2[0]);$i++){
                    $out1[0][$i]=explode("\"", $out1[0][$i])[1];
                    $out2[0][$i]=explode("\n", $out2[0][$i])[2];
                    $out2[0][$i]=trim($out2[0][$i]);
                }
                $data=array();
                for($i=0;$i<count($out2[0]);$i++){
                     $data[$out1[0][$i]] = $out2[0][$i];
                }     
                break;
            
           
        }
    
        // store the method
        $return_obj->setMethod($request_method);
    
        // set the raw data, so we can access it if needed (there may be
        // other pieces to your requests)
        $return_obj->setRequestVars($data);
    
        if(isset($data['data']))
        {
            // translate the JSON to an Object for use however you want
            $return_obj->setData(json_decode($data['data']));
        }
        return $return_obj;
    }

public static function sendResponse($status = 200, $body = '', $content_type = 'text/html')  
    {  
        $status_header = 'HTTP/1.1 ' . $status . ' ' . RestUtils::getStatusCodeMessage($status);  
        // set the status  
        header($status_header);  
        // set the content type  
        header('Content-type: ' . $content_type);  
  
        // pages with body are easy  
        if($body != '')  
        {  
            // send the body  
            echo $body;  
            exit;  
        }  
        // we need to create the body if none is passed  
        else  
        {  
            // create some body messages  
            $message = '';  
  
            // this is purely optional, but makes the pages a little nicer to read  
            // for your users.  Since you won't likely send a lot of different status codes,  
            // this also shouldn't be too ponderous to maintain  
            switch($status)  
            {  
                case 401:  
                    $message = 'You must be authorized to view this page.';  
                    break;  
                case 404:  
                    $message = 'The requested URL ' . $_SERVER['REQUEST_URI'] . ' was not found.';  
                    break;  
                case 500:  
                    $message = 'The server encountered an error processing your request.';  
                    break;  
                case 501:  
                    $message = 'The requested method is not implemented.';  
                    break;  
            }  
  
            // servers don't always have a signature turned on (this is an apache directive "ServerSignature On")  
            $signature = ($_SERVER['SERVER_SIGNATURE'] == '') ? $_SERVER['SERVER_SOFTWARE'] . ' Server at ' . $_SERVER['SERVER_NAME'] . ' Port ' . $_SERVER['SERVER_PORT'] : $_SERVER['SERVER_SIGNATURE'];  
  
            // this should be templatized in a real-world solution  
            $body = '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">  
                        <html>  
                            <head>  
                                <meta http-equiv="Content-Type" c/html; charset=iso-8859-1">  
                                <title>' . $status . ' ' . RestUtils::getStatusCodeMessage($status) . '</title>  
                            </head>  
                            <body>  
                                <h1>' . RestUtils::getStatusCodeMessage($status) . '</h1>  
                                <p>' . $message . '</p><div class="aritcle_card flexRow">
                                                        <div class="artcardd flexRow">
                                                                <a class="aritcle_card_img" href="/ai/1268" title="Imagine Me"><img
                                                                                src="https://img.php.cn/upload/ai_manual/001/431/639/68b6db4754952805.png" alt="Imagine Me"  onerror="this.onerror='';this.src='/static/lhimages/moren/morentu.png'" ></a>
                                                                <div class="aritcle_card_info flexColumn">
                                                                        <a href="/ai/1268" title="Imagine Me">Imagine Me</a>
                                                                        <p>利用AI技术创建自己的个人模型</p>
                                                                </div>
                                                                <a href="/ai/1268" title="Imagine Me" class="aritcle_card_btn flexRow flexcenter"><b></b><span>下载</span> </a>
                                                        </div>
                                                </div>  
                                <hr />  
                                <address>' . $signature . '</address>  
                            </body>  
                        </html>';  
  
            echo $body;  
            exit;  
        }  
    }  

    public static function getStatusCodeMessage($status)
    {
        // these could be stored in a .ini file and loaded
        // via parse_ini_file()... however, this will suffice
        // for an example
        $codes = Array(
            100 => 'Continue',
            101 => 'Switching Protocols',
            200 => 'OK',
            201 => 'Created',
            202 => 'Accepted',
            203 => 'Non-Authoritative Information',
            204 => 'No Content',
            205 => 'Reset Content',
            206 => 'Partial Content',
            300 => 'Multiple Choices',
            301 => 'Moved Permanently',
            302 => 'Found',
            303 => 'See Other',
            304 => 'Not Modified',
            305 => 'Use Proxy',
            306 => '(Unused)',
            307 => 'Temporary Redirect',
            400 => 'Bad Request',
            401 => 'Unauthorized',
            402 => 'Payment Required',
            403 => 'Forbidden',
            404 => 'Not Found',
            405 => 'Method Not Allowed',
            406 => 'Not Acceptable',
            407 => 'Proxy Authentication Required',
            408 => 'Request Timeout',
            409 => 'Conflict',
            410 => 'Gone',
            411 => 'Length Required',
            412 => 'Precondition Failed',
            413 => 'Request Entity Too Large',
            414 => 'Request-URI Too Long',
            415 => 'Unsupported Media Type',
            416 => 'Requested Range Not Satisfiable',
            417 => 'Expectation Failed',
            500 => 'Internal Server Error',
            501 => 'Not Implemented',
            502 => 'Bad Gateway',
            503 => 'Service Unavailable',
            504 => 'Gateway Timeout',
            505 => 'HTTP Version Not Supported'
        );

        return (isset($codes[$status])) ? $codes[$status] : '';
    }
}

class RestRequest
{
    private $request_vars;
    private $data;
    private $http_accept;
    private $method;

    public function __construct()
    {
        $this->request_vars      = array();
        $this->data              = '';
        $this->http_accept       = (strpos($_SERVER['HTTP_ACCEPT'], 'json')) ? 'json' : 'xml';
        $this->method            = 'get';
    }

    public function setData($data)
    {
        $this->data = $data;
    }

    public function setMethod($method)
    {
        $this->method = $method;
    }

    public function setRequestVars($request_vars)
    {
        $this->request_vars = $request_vars;
    }

    public function getData()
    {
        return $this->data;
    }

    public function getMethod()
    {
        return $this->method;
    }

    public function getHttpAccept()
    {
        return $this->http_accept;
    }

    public function getRequestVars()
    {
        return $this->request_vars;
    }
    
   
    
    
    
}


$data = RestUtils::processRequest();

switch($data->getMethod())
{
    case 'get':
      //  print_r($data->getRequestVars());
        $infoType=$data->getRequestVars()['infoType'];
        if (array_key_exists("username",$data->getRequestVars())) {
            $username=$data->getRequestVars()['username'];
            if($data->getHttpAccept() == 'json'){
                if($infoType=="health"){
                     $healthService=new HealthService();
                     $result=$healthService->getUserHealth($username);
                     if($result==""){
                         RestUtils::sendResponse(404, "Not Found");
                     }
                     else{
                         RestUtils::sendResponse(200, json_encode($result), 'application/json');
                     }
                }
           
            }
            else if ($data->getHttpAccept() == 'xml'){
                if($infoType=="health"){
                    $healthService=new HealthService();
                    $result=$healthService->getUserHealth($username);
                    if($result==""){
                        RestUtils::sendResponse(404, "NOT FOUND");
                    }
                    else{
                        $health=new HealthXML();
                        RestUtils::sendResponse(200, $health->create_xml($result),'application/xml');
                    }
                }
              
            }
        }

        break;
        
    case 'post':
        $infoType=$data->getRequestVars()['infoType'];
        if($infoType=="health"){
           $username=$data->getRequestVars()['username'];
           $height=$data->getRequestVars()['height'];
           $weight=$data->getRequestVars()['weight'];
           $date=$data->getRequestVars()['date'];
           $healthService=new HealthService();
           $ID=$healthService->addHealthWithDate($username, $height, $weight, $date); 
           $health=new HealthXML();
           $data_array = array(
            array(
                    'ID' => $ID,                 
                )
            );   
           RestUtils::sendResponse(201, $health->create_IDxml($data_array));
        }
         
        break;
     
    case 'put':
       // print_r($data->getRequestVars());
        $infoType=$data->getRequestVars()['infoType'];
      //  echo $infoType;
      //  echo $infoType=="health"?"true":"false";
        if($infoType=="health"){
            $ID=$data->getRequestVars()['ID'];
            $username=$data->getRequestVars()['username'];
            $height=$data->getRequestVars()['height'];
            $weight=$data->getRequestVars()['weight'];
            $date=$data->getRequestVars()['date'];
            $healthService=new HealthService();
            $result=$healthService->modifyHealthWithDate($ID, $username, $height, $weight, $date);
            if($result=="false"){
                RestUtils::sendResponse(400, "Bad Request");
            }
            else{
                $health=new HealthXML();
                RestUtils::sendResponse(200, $health->create_xml($result),'application/xml');
            }
        } 
       
        break;
     
    case 'delete':
            $infoType=$data->getRequestVars()['infoType'];
           if($infoType=="health"){
               $ID=$data->getRequestVars()['ID'];          
               $healthService=new HealthService();
               $result=$healthService->deleteHealth($ID);
               if($result==false){
                    RestUtils::sendResponse(404, "Not Found");
               }
               else{
                    RestUtils::sendResponse(204, "No Content");
               }
            } 
           
        break;        
}

class HealthXML{
   
    //  创建XML单项
    function create_item($ID_data,$username_data, $height_data , $weight_data, $dateTime_data)
    {
        $item = "<item>\n";
        $item .= "<ID>" . $ID_data . "</ID>\n";
        $item .= "<username>" . $username_data . "</username>\n";
        $item .= "<height>" . $height_data . "</height>\n";
        $item .= "<weight>" . $weight_data . "</weight>\n";
        $item .= " <dateTime>" . $dateTime_data . "</dateTime>\n";
        $item .= "</item>\n";
        return $item;
    }
    
    function create_xml($data_array){
        $title_size = 1;
        $xml = "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
        $xml .= "<article>\n";
        foreach ($data_array as $data) {
            $xml .= $this->create_item($data['ID'],$data['username'], $data['height'], $data['weight'],$data['dateTime']);
        }
        $xml .= "</article>\n";
        return $xml;
    }
    
  
    
    //  创建XML单项
    function create_IDitem($ID_data)
    {
        $item = "<item>\n";
        $item .= "<ID>" . $ID_data . "</ID>\n";     
        $item .= "</item>\n";
        return $item;
    }
    
    function create_IDxml($data_array){
        $title_size = 1;
        $xml = "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
        $xml .= "<article>\n";
        foreach ($data_array as $data) {
            $xml .= $this->create_IDitem($data['ID']);
        }
        $xml .= "</article>\n";
        return $xml;
    }
 
}


?>

难点是对于http请求头的解析真是让我吐血啊，那个时候我还不知道chrome可以看请求内容，我的做法是简陋地输出来看。之后解析时狂补了一通正则表达式，最后用正则顺利解析了。

我这不能API直接用啊，里面有我网站里分析健康数据的例子，你们也可以看到，后半段大量地出现“health"，就是我的网站中的获取健康数据的例子啊。

因为时间紧急，所以只用半天写出来的API，大概是又简陋又有很多不足的吧。不过想到这个项目最终检查时有那么多同学没有实现rest，而我没有用框架自己学习rest，实现了一个自己的api，也是挺开心的。

以上就介绍了自己创建一个Rest API，包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。