Given a list of strings of the same length and no special characters:

给定长度相同且没有特殊字符的字符串列表：

List<String> myStringArray = List.of( "xxxyyyjjjabcdefg", xxxyyyjjjabcdefg", "xxxyyyxxxabcdefg");

List<字符串>myStringArray=List.of(“xxxyyyjjabcDefg”，xxxyyyjjabcDefg“，”xxxyyyxxxabcDefg“)；

I can find the longest common sub string of the list:

我可以找到列表中最长的公共子字符串：

String lengthOfAllStrings = myStringArray.stream().min(Comparator.comparingInt(String::length)).get();  
List<char[]> myCharArray = myStringArray.stream().map(String::toCharArray).collect(Collectors.toList());  
StringBuilder longestCommonSubString = StringBuilder();  
StringBuilder currentLongestSubString = new StringBuilder();  
  
for(int i = 0; i < lengthOfAllStrings.length(); i++) {
int finalI = i;
if(myCharArray.stream().anyMatch((a) -> a[finalI] == ( (myCharArray.stream().collect(Collectors.groupingBy(x -> x[finalI]))).values().size == 1 ? (myCharArray.stream().collect(Collectors.groupingBy(x -> x[finalI]))).entrySet().iterator().next().getKey() : '!'))) {  
  longestCommonSubString.append((myCharArray.stream().collect(Collectors.groupingBy( x -> x[finalI]))).entrySet().iterator().next().getKey());  
 } else {  
  currentLongestSubString.append(longestCommonSubString);  
  longestCommonSubString = new StringBuilder();  
 }  
}  
System.out.println("The Longest Common Sub String = " + Stream.of(longestCommonSubString.toString(), currentLongestSubString.toString()).max(Comparator.comparingInt(String::length)).get());

Output: The Longest Common Sub String = abcdefg

输出：最长公共子字符串=ABCDEFG

but what if the list contains strings of different length:

但是，如果列表包含不同长度的字符串怎么办：

List<String> myStringArray = List.of( "xxxyyy", xxxyyy", "yyy");

List<字符串>myStringArray=List.of(“xxxyyy”，xxxyyy“，”yyy“)；

Desired Output: The Longest Sub String = yyy

所需输出：最长的子字符串=yyy

Also, is there a way to do all this with a one liner and not use a for loop ?

另外，有没有一种方法可以在不使用for循环的情况下使用one linder来完成所有这些任务？

You can try this:

您可以尝试以下操作：

import java.util.*;

public class LongestCommonSubstring {
    public static String findLongestCommonSubstring(List<String> strings) {
        if (strings == null || strings.isEmpty()) {
            return "";
        }

        String firstString = strings.get(0);
        int maxLength = firstString.length();
        String longestCommonSubstring = "";

        for (int i = 0; i < maxLength; i++) {
            for (int j = i + 1; j <= maxLength; j++) {
                String substring = firstString.substring(i, j);
                boolean isCommon = strings.stream().allMatch(s -> s.contains(substring));
                if (isCommon && substring.length() > longestCommonSubstring.length()) {
                    longestCommonSubstring = substring;
                }
            }
        }

        return longestCommonSubstring;
    }

    public static void main(String[] args) {
        List<String> myStringArray = List.of("xxxyyy", "xxxyyy", "yyy");
        String longestCommonSubstring = findLongestCommonSubstring(myStringArray);
        System.out.println("The Longest Common Substring = " + longestCommonSubstring);
    }
}

This code will work for lists of strings with different lengths and will find the longest common substring among them.

此代码将用于不同长度的字符串列表，并将找到其中最长的公共子字符串。

As for doing this with a one-liner and without a for loop, it's not practical because finding the longest common substring among different-length strings typically requires comparing all possible substrings, which cannot be efficiently accomplished with a one-liner or without some form of iteration. Hope this can help :)

至于使用一行程序而不使用for循环来执行此操作，这是不实际的，因为在不同长度的字符串中查找最长的公共子字符串通常需要比较所有可能的子字符串，而使用一行程序或不使用某种形式的迭代无法有效地实现这一点。希望这能有所帮助：)