以下是使用Java编写的解决方案：

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String s = scanner.nextLine();
        String t = scanner.nextLine();
        int maxSimilarity = getMaxSimilarity(s, t);
        System.out.println(maxSimilarity);
    }

    public static int getMaxSimilarity(String s, String t) {
        int maxSimilarity = 0;
        int n = s.length();
        int m = t.length();
        int[][] dp = new int[n + 1][m + 1];

        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= m; j++) {
                if (s.charAt(i - 1) == t.charAt(j - 1)) {
                    dp[i][j] = dp[i - 1][j - 1] + 1;
                    maxSimilarity = Math.max(maxSimilarity, dp[i][j]);
                }
            }
        }

        int prefixLength = maxSimilarity;
        int suffixLength = maxSimilarity;

        // 计算最长相同前缀的长度
        for (int i = maxSimilarity + 1; i <= n; i++) {
            if (s.charAt(i - 1) == t.charAt(i - 1 - maxSimilarity)) {
                prefixLength++;
            } else {
                break;
            }
        }

        // 计算最长相同后缀的长度
        for (int i = maxSimilarity + 1; i <= m; i++) {
            if (s.charAt(n - i + maxSimilarity) == t.charAt(m - i)) {
                suffixLength++;
            } else {
                break;
            }
        }

        return prefixLength * suffixLength;
    }
}

这段代码首先读取两个输入字符串s和t，然后使用动态规划算法计算出最长相同前缀的长度和最长相同后缀的长度。接着，根据最长相同前缀和最长相同后缀的长度计算相似度，并输出结果。

希望这段代码能够帮助到你！