Write a Java program to check whether a substring appears before a period(.) within a given string. Sample Output:The given strings is: testabc.testIs 'abc' appear before period? trueThe given string is: test.abctestIs 'abc' appear before period? false

Sure, here is a simple Java program that checks whether a substring appears before a period in a given string.

public class Main {
    public static void main(String[] args) {
        checkSubstring("testabc.test", "abc");
        checkSubstring("test.abctest", "abc");
    }

    public static void checkSubstring(String str, String sub) {
        int periodIndex = str.indexOf(".");
        int subIndex = str.indexOf(sub);

        if (subIndex != -1 && periodIndex != -1 && subIndex < periodIndex) {
            System.out.println("The given string is: " + str);
            System.out.println("Is '" + sub + "' appear before period? true");
        } else {
            System.out.println("The given string is: " + str);
            System.out.println("Is '" + sub + "' appear before period? false");
        }
    }
}

This program defines a method checkSubstring that takes a string and a substring as parameters. It finds the index of the period and the substring in the string using the indexOf method. If both indices are not -1 (which means both the period and the substring exist in the string) and the index of the substring is less than the index of the period (which means the substring appears before the period), it prints that the substring appears before the period. Otherwise, it prints that the substring does not appear before the period. The main method tests this method with two example strings.