How do I search for a string within a string

In this Q&A, we'll go over options available to search for a string within a string.

String class provides a couple of methods - - indexOf  and contains - to search for a string 

On top of that, StringUtils class that's part of Apache Commons Lang provides methods to search string ignoring case and to search for one of many strings.

See demo code below

package com.javahowdoi.string;

import org.apache.commons.lang3.StringUtils;

import static junit.framework.TestCase.assertEquals;

public class SearchDemo {

    public static void main(String[] args) {

        String  s = "Pennsylvania";

        String s1 = "van";

        String s2 = "Van";

        assertEquals( "indexOf equals 7", 7, s.indexOf(s1) );

        assertEquals( "contains match ", true, s.contains(s1) );

        assertEquals( "contains don't match ", false, s.contains(s2) );

        assertEquals( "containsIgnoreCase match ", true, StringUtils.containsIgnoreCase(s, s2) );

        assertEquals( "containsAny match ", true, StringUtils.containsAny(s, s1, s2) );

    }

}