给出两个字符串，求出其最大的相同子串。

package stringtest;
/**
 * 思路：截取最小串（截取的时候先截取最大长度，然后依次减一），去匹配大串。
 */
import java.util.ArrayList;
import java.util.List;

public class MaxSubString {
    
    public static void main(String[] args) {
        String s1 = "afea";
        String s2 = "afebcd";
        System.out.println(maxSubString(s1, s2));
        
    }
    //求str2在str1中最大的相同子串
    public static List<String> maxSubString(String str1,String str2) {
        String maxString = (str1.length() >= str2.length()) ? str1 : str2;
        String minString = (str1.length() >= str2.length()) ? str2 : str1;
        List<String> listSring = new ArrayList<String>();
        for (int i = 0; i < minString.length(); i++) {
            for (int x = 0 , y = minString.length() - i -1; y < minString.length(); x++ , y++) {
                //substring是左闭右开的
                if (maxString.contains(minString.substring(x, y+1))) {
                    listSring.add(minString.substring(x, y+1));
                }
            }
            if (!listSring.isEmpty()) {
                return listSring;
            }
        }
        return listSring;
    }
}