excel bom

    function downloadCsvData($title, $csv_data = array(), $file_name = null) {
        $csv_string = null;
        $csv_row    = array();


        if (empty($file_name)) {
            $file_name = date('Y-m-d').".csv";
        }


        foreach( $csv_data as $key => $csv_item ) {
            if ($key === 0) {
                $csv_row[]    = implode("," , $csv_item);
                continue;
            }
            $current = array();
            foreach($csv_item AS $item) {
                $current[] = is_numeric($item)?$item:'"'.str_replace('"', '""', $item).'"';
            }
            $csv_row[]    = implode( "," , $current );
        }
        $csv_string .= implode( "\r\n", $csv_row );
        //echo setlocale(LC_CTYPE ,"ko_KR.eucKR");
        header("Content-type:application/vnd.ms-excel;charset=utf-8");
        header("Content-Disposition:filename=".date('Y-m-d').".csv");
        header("Content-Description: PHP4 Generated Data");

	// 不好使
        //echo '\xEF\xBB\xBF';
	// 这样才能正确添加BOM,以免乱码
        echo "\xEF\xBB\xBF".$title."\r\n";
        echo $csv_string;
    }

在java里, 文件内容最前面加"\uFEFF"