現在往往內容服務類的公司都用到了抓取技術,比如房產企業對租房信息的抓取,招聘企業對招聘信息的抓取,彩票行業對開獎信息的抓取,以滿足項目需要提供內容服務。
這裏介紹下PHP對各種形式的數據抓取,包括對json數據,xml文件,js程序,html頁面的抓取。
先寫一個通用採集函數(比如採用file_get_contents來抓取)。當然php的抓取不只這一種,更多請求方式點擊查看http://blog.csdn.net/jiedao_liyk/article/details/59553565,這裏着重分析對抓取數據的解析,以下對彩票開獎號抓取分析:
通用抓取函數
private function get_contents($url){
$opts = array(
'http'=>array(
'method'=>"GET",
'timeout'=>1,
)
);
$context = stream_context_create($opts);
return @file_get_contents($url,false,$context);
}
所有采集的基礎是找到合適的抓取源,所以抓取第一步是尋找合適的抓取源,由於採集是依賴與別人的網站,所以要儘可能的多找寫抓取源,確保數據穩定。
1. 抓取json數據及解析方法(可實際測試代碼效果)
private function fetch_by_icaile(){
$data = array();
$url = "http://pub.icaile.com/jx11x5kjjg.php?action=chart&date=today&random=0693198428990367&id=505&async=true";
$content = $this->get_contents($url);
$obj = json_decode($content);
$d1 = $obj->data[0];
if($d1){
$data['winnum'] = implode(' ',$d1->list);
$data['issue'] = '20'.$d1->dateNumber;
$data['time'] = time();
}
return $data;
}
2. 抓取xml數據及解析方法(可實際測試代碼效果)
private function fetch_by_500wan(){
$data = array();
$url = 'http://kaijiang.500.com/static/info/kaijiang/xml/';
$url = $url."/".date("Ymd").".xml?_=".time();
$xml = simplexml_load_file($url);
if($p = $xml->row) {
$issue = $p['expect'];
$winnum = str_replace(',',' ',$p['opencode']);
if (empty($issue) || empty($winnum)) {
return $data;
}
$issue = substr($issue,0, 8).substr($issue,-2);
$data['issue'] = $issue;
$data['winnum'] = $winnum;
$data['time'] = time();
}
return $data;
}
3. 抓取js數據及解析方法(可實際測試代碼效果)
private function fetch_tjssc_by_huacai(){
$data = array();
$url = "http://www.huacai.com/html_cn/js/lot_award_163_i_20.js";
$content = $this->get_contents($url);
$content = str_replace("lot_award.set_data(",'', $content);
$content = str_replace(")",'', $content);
preg_match("/{.*?content\":\"(.*?)\",\"end_time.*?issue_num\":\"(.*?)\",\"lottery_id.*?}/i", $content,$match);
$issue = substr($match['2'],0,8).substr($match['2'],-2);
$winnum = str_replace(",", " ", $match[1]);
if(!$issue || !$winnum || strlen($issue) != 10 || strlen($winnum)!=9 ){
return $data;
}
$data['issue'] = $issue;
$data['winnum'] = $winnum;
$data['time'] = time();
return $data;
}
4. 抓取html數據及解析方法(可實際測試代碼效果)
private function fetch_by_tjflcpw(){
$data = array();
$url = "http://www.tjflcpw.com/index.aspx?".time();
$content = file_get_contents($url);
$content = str_replace("\r\n","",$content);
preg_match("/SSC_WinMessage.aspx\">(.*?)<\/a>/i", $content,$match);
$pos1 = strpos($content, "<!--時時彩-->");
$content = substr($content, $pos1,2400);
preg_match("/<li>(.*)<\/li><li>(.*)<\/li><li>(.*)<\/li><li>(.*)<\/li><li>(.*)<\/li>/i",$content,$codes);
$qishu = substr(trim($match[1]),0,11);
$kjhm = $codes[1]." ".$codes[2]." ".$codes[3]." ".$codes[4]." ".$codes[5];
if (empty($qishu) || empty($kjhm)) {
return $data;
}
$issue = substr($qishu,0, 8).substr($qishu,-2);
$data['issue'] = $issue;
$data['winnum'] = $kjhm;
$data['time'] = time();
return $data;
}
抓取不到網頁數據,一些應該注意的地方
- 有些網頁需要設置特定的UserAgent,不同的UserAgent會得到不同的網頁請求了,例如手機瀏覽器和PC瀏覽器,就會得到不同的網頁文件
ini_set('user_agent','Mozilla/4.0 (compatible; MSIE 6.0)');
- 還有就是抓取到的內容是亂碼的問題,可以嘗試通過下面方法解決(換一種抓取方式並相應設置客戶端支持gzip壓縮)
private function fetch_by_lehecaissc(){
$data = array();
$url = 'http://baidu.lecai.com/lottery/ajax_latestdrawn.php?lottery_type=200';
$ch = curl_init();
curl_setopt($ch, CURLOPT_ENCODING, "gzip" ); //設置爲客戶端支持gzip壓縮
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30 ); //設置連接等待時間
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_URL, $url );
$output =curl_exec( $ch );
curl_close($ch);
$return=array();
if($output){
$result = json_decode($output,true);
$winnumarr=$result['data'][0]['result']['result'][0]['data'];
$issue=$result['data'][0]['phase'];
$return['issue']=$issue;
$return['winnum']=implode(' ',$winnumarr);
}
$return['time'] = time();
return $return;
}
大家看到好的抓取,特殊的抓取,或者抓取遇到的特殊問題及解決辦法,歡迎評論留言,看到會及時回覆,致謝!