.split(/.{4}/)

這樣分割產(chǎn)生的結(jié)果最后一個(gè)元素是空字符串

/(.+)(?=\.{4})/

<?php
$str = "12.3....ed....6756....434dsfsd....";
preg_match_all('/(.*?)\.\.\.\./',$str,$b);
print_r($b);
?>
輸出：
Array
(
    [0] => Array
        (
            [0] => 12.3....
            [1] => ed....
            [2] => 6756....
            [3] => 434dsfsd....
        )

    [1] => Array
        (
            [0] => 12.3
            [1] => ed
            [2] => 6756
            [3] => 434dsfsd
        )

)

分組的個(gè)數(shù)應(yīng)該是確定的，沒發(fā)寫不確定個(gè)數(shù)的分組吧

正則我不熟，現(xiàn)學(xué)現(xiàn)賣...

這樣試一下？

.+?\.{4}

共找到 4 處匹配：
12.3....
ed....
6756....
434dsfsd....

正則表達(dá)式: (\.{4})

        String[] attr = "12.3....ed....6756....434dsfsd....".split("(\\.{4})");

String string = "12.3....ed....6756....434dsfsd....";

Pattern pattern = Pattern.compile("(\\.{4})");
Matcher matcher = pattern.matcher(string);
System.out.println(matcher.matches());
int pre = 0;
//查找符合規(guī)則的子串
while (matcher.find()) {
    //獲取 字符串
    System.out.println(matcher.group());
    //獲取的字符串的首位置和末位置
    System.out.println(string.substring(pre, matcher.start()));
    pre = matcher.end();
}