文件内容操作的分页类

<?php 
class StrPage {
	private $current;			//当前页  
	private $file;				//操作文件
	private $totalPage;			//总的页数
	private $url;				//传递的参数
	private $pageLen;			//每页显示的长度

	function __construct( $file,$len = 200 ){
		$this->file = file_get_contents($file);
		$this->pageLen = $len;
		$this->current = isset($_GET['page'])?$_GET['page']:1;
		$this->totalPage = $this->getTotalPage();
		$this->url = $this->getUrl();
	}


	//获取到这个文件总的长度
	private function getTotalPage(){
		return ceil(strlen($this->file)/$this->pageLen);
	}

	//获取当前传递的参数,保留参数，page参数动态变化
	private function getUrl(){
		$url =parse_url($_SERVER['REQUEST_URI']);
		parse_str($url['query'],$queryArr);
		unset($queryArr['page']);
		$queryStr = http_build_query($queryArr);
		return  $url['path'].'?'.$queryStr.'&page=';		
	}


	//首页
	private function first(){
		if($this->current>1)
			return "<a href='".$this->url."1'>首页</a>";
	}
	//上一页
	private function pre(){
		if( $this->current > 1 )
			return "<a href='".$this->url.($this->current-1)."'>上一页</a>";
	}
	//下一页
	private function next(){
		if( $this->current < $this->totalPage)
			return "<a href='".$this->url.($this->current+1)."'>下一页</a>";
	}
	//最后一页
	private function end(){
		if( $this->current < $this->totalPage )
			return "<a href='".$this->url.$this->totalPage."'>末页</a>";
	}

	public function pageList(){
		$pageListStr = '';
		for ($i=1;$i<=$this->totalPage;$i++){
			if($i==$this->current){
				$pageListStr.="<span style='font-size:20px;color:#f00'>".$i."</span> ";
			}else{
			$pageListStr.="<a href='".$this->url.$i."'>".$i." </a>";
			}
		}
		return $pageListStr;
		}

		public function pageStyle($style=1){
			switch ($style){
				case 1:
					return "共有".$this->totalPage."页".$this->first().$this->pre().$this->pageList().$this->next().$this->end();
					break;
				case 2;
				return $this->pageList();
				break;
			}
		}

		public function getContents(){
		$prePageLen = strlen($this->subStrs($this->current-1));
		$currentPageLen = strlen($this->subStrs($this->current));
		return substr($this->file, $prePageLen,$currentPageLen-$prePageLen);
		}

		public function subStrs($page){		
			$string = '';
			$len= $page*$this->pageLen;
			for( $i=0; $i<$len; $i++ ){
					if( ord(substr($this->file,$i,1))>0xa0 ){
						$string .= substr($this->file,$i,3);
						$i = $i+2;
				}else{
					$string .= substr($this->file, $i,1);
				}
			}
			return $string;
			
		}

}