PHPExcel导出数据量较大时内存溢出

TP框架：

类的开头引入了PHPExcel类库的文件

然后在方法里设置了存储缓存方式就ok了：

列入：

public function getDownLoad(){

         //此处是设置缓存方式

        $cacheMethod = PHPExcel_CachedObjectStorageFactory::cache_in_memory_gzip;  
        $cacheSettings = array();  
        PHPExcel_Settings::setCacheStorageMethod($cacheMethod,$cacheSettings);

        /****此处是data数据*****/

        $cellTag = array("班级","学号","姓名","性别");
        $excelObj = new HelperPHPExcel();
        $author = "Student";
        $title  = "学生信息".date("Y-m-d", $startTime)."至". date("Y-m-d", $endTime);
        $excelObj->setCreator($author, $title);
        $excelObj->downloadToExcel($title, $data, $cellTag);