How to StringUtils in Java

Mohammad Irfan Feb 02, 2024

Java Java StringUtils

This tutorial introduces what StringUtils is and how to utilize it in handling String in Java.

StringUtils is a class used to handle String and provides more utility methods than the Java String class. This class does not belong to the Java package; instead, it belongs to the Apache Commons Library.

To use this class in your package, you must first include its JAR file in your project and import the StringUtils class in your Java source code.

If you are working with the maven project, use the below dependency in the pom.xml file. It will add the required JARs to your current project.

<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.12.0</version>
</dependency>

This class can be found in the org.apache.commons.lang3 package and the signature of this class look like below.

Syntax of StringUtils Class:

public class StringUtils extends Object

The constructor of the StringUtils Class:

StringUtils() // no arg constructor

The following are some common operations that StringUtils supports.

Operation	Description
`IsEmpty`/`IsBlank`	It checks if a String contains text or not.
`Trim`/`Strip`	It removes the leading and trailing whitespace of the String.
`Equals`/`Compare`	It compares two strings in a null-safe manner.
`startsWith`	It checks if a String starts with a prefix in a null-safe manner.
`endsWith`	It checks if a String ends with a suffix in a null-safe manner.
`IndexOf`/`LastIndexOf`/`Contains`	It returns a null-safe index-of checks.
`IndexOfAny`/`LastIndexOfAny/IndexOfAnyBut`/`LastIndexOfAnyBut`	To find index-of any of a set of Strings.
`ContainsOnly`/`ContainsNone/ContainsAny`	It checks if String contains only/none/any of these characters
`Split`/`Join`	It splits a String into an array of substrings and vice versa.
`Remove`/`Delete`	It removes part of a String.

`StringUtils` Example in Java

In this example, we used some standard methods of the StringUtils class to understand how the class works with the String. This class is similar to the String class in Java except that it provides more utility methods to work with String.

See the example below.

import org.apache.commons.lang3.StringUtils;

public class SimpleTesting {
  public static void main(String[] args) {
    // Get abbreviation of string
    String val = StringUtils.abbreviate("Delft", 4);
    System.out.println(val);
    // Capitalize string
    val = StringUtils.capitalize("delft");
    System.out.println(val);
    // Chop string
    val = StringUtils.chop("delft");
    System.out.println(val);
    // Compare two strings
    int a = StringUtils.compare(val, val);
    System.out.println(a);
    // find substring in string
    boolean b = StringUtils.contains("delft", "ft");
    System.out.println(b);
    // Find index of a char in string
    int c = StringUtils.indexOf(val, 'f');
    System.out.println(c);
    // Find last index of a char in string
    int d = StringUtils.lastIndexOf("delftstack", 't');
    System.out.println(d);
    // Lowercase string
    val = StringUtils.lowerCase("DELFSTACK");
    System.out.println(val);
    // Repeat string
    val = StringUtils.repeat("DELF", 2);
    System.out.println(val);
    // Reverse string
    val = StringUtils.reverse("Delft");
    System.out.println(val);
    // Truncate string
    val = StringUtils.truncate("Delft", 2);
    System.out.println(val);
    // Uppercase string
    val = StringUtils.upperCase("Delft");
    System.out.println(val);
  }
}

Output:

D...
Delft
delf
0
true
3
6
delfstack
DELFDELF
tfleD
De
DELFT

StringUtils Example in Java

`StringUtils` Example in Java