Find second index of a substring in a String in Java

By Atul Rai | Last Updated: October 22, 2022 Previous       Next

In Java, we can use the overloaded method indexOf(String str, int fromIndex) of the String class to get the second index of a substring from a given string.

The return type of indexOf(String str, int fromIndex) method is int and it will return -1 if there is no such occurrence found.

public int indexOf(String str, int fromIndex)

1. Java indexOf(String str, int fromIndex)

A complete Java example to find the second occurrence of a substring in a string.

package org.websparrow;

public class SecondIndex {
    
    public static void main(String[] args) {
        // Test Case 1
        final String str1 = "I am a software developer and I love technology.";
        int result1 = getSecondIndex(str1, "I"); // 30
        System.out.println(result1);

        // Test Case 2
        final String str2 = "Lorem Ipsum Lorem Ipsum";
        int result2 = getSecondIndex(str2, "m"); // 10
        System.out.println(result2);

        // Test Case 3
        final String str3 = "Live and Let Live";
        int result3 = getSecondIndex(str3, "n"); // -1
        System.out.println(result3);
    }

    private static int getSecondIndex(final String str, final String subStr) {
        return str.indexOf(subStr, str.indexOf(subStr) + 1);
    }
}

Output

30
10
-1

2. Apache Commons Lang 3, StringUtils

Alternatively, we can use the Apache commons-lang3 library, StringUtils.ordinalIndexOf(CharSequence str, CharSequence searchStr, int ordinal); API to get the second index of a substring from a given string.

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.12.0</version>
</dependency>

package org.websparrow;

import org.apache.commons.lang3.StringUtils;

public class SecondIndexApache {

    public static void main(String[] args) {
        // Test Case 1
        final String str1 = "I am a software developer and I love technology.";
        int result1 = StringUtils.ordinalIndexOf(str1, "I", 2); // 30
        System.out.println(result1);

        // Test Case 2
        final String str2 = "Lorem Ipsum Lorem Ipsum";
        int result2 = StringUtils.ordinalIndexOf(str2, "m", 2); // 10
        System.out.println(result2);

        // Test Case 3
        final String str3 = "Live and Let Live";
        int result3 = StringUtils.ordinalIndexOf(str3, "n", 2); // -1
        System.out.println(result3);
    }
}

Output

30
10
-1

3. References

1. Java- String.indexOf
2. Apache Commons Lang 3- StringUtils