How to know if a given string is substring from another string in Java

Question

Hi I have to compute if a given string is substring of a bigger string. For example

String str = \"Hallo my world\";
String substr = \"my\"

<

Answer 1

I think there is a String function that does just what you are asking: String.indexOf(String).

See this link: http://download.oracle.com/javase/1.4.2/docs/api/java/lang/String.html#indexOf(java.lang.String)

So, then you could write this function:

public boolean isSubstring(String super, String sub) {
    return super.indexOf(sub) >= 0;
}