What is ObjectUtils.isNotEmpty in Java?
isNotEmpty() is a ObjectUtils class that checks if the object passed as an argument is:
- not empty
- not null
The following types are supported by this method.
- CharSequence
- Array
- Collection
- Map
The method returns true if the input object of the above type is not empty or does not point to null. Otherwise, the method returns false.
How to import ObjectUtils
The definition of ObjectUtils can be found in the Apache Commons Lang package, which we can add to the Maven project by adding the following dependency to the pom.xml file.
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.12.0</version>
</dependency>
For other versions of the commons-lang package, refer to the Maven Repository.
You can import the ObjectUtils class as follows.
import org.apache.commons.lang3.ObjectUtils;
Syntax
public static boolean isNotEmpty(final Object object)
Parameters
object: The object to test.
Return value
The method returns true if the input object of any of the types outlined above is not empty or is not null. Otherwise, the method returns false.
Code
package org.apache.commons.lang3;import org.apache.commons.lang3.ObjectUtils;import java.util.ArrayList;import java.util.List;public class main {public static void main(String[] args) {List<String> stringList = new ArrayList<>();System.out.println("The output of ObjectUtils.isNotEmpty() when an empty list is passed is " + ObjectUtils.isNotEmpty(stringList));stringList.add("hello");System.out.println("The output of ObjectUtils.isNotEmpty() when a non-empty list is passed is " + ObjectUtils.isNotEmpty(stringList));stringList = null;System.out.println("The output of ObjectUtils.isNotEmpty() when a null is passed is " + ObjectUtils.isNotEmpty(stringList));}}
Output
The output of ObjectUtils.isNotEmpty() when an empty list is passed is false
The output of ObjectUtils.isNotEmpty() when a non-empty list is passed is true
The output of ObjectUtils.isNotEmpty() when a null is passed is false
Explanation
Example 1: An empty list
List<String> stringList = new ArrayList<>();
The method returns false when the list above is passed because the list is empty.
Example 2: A non-empty list
list = ["hello"]
The method returns true when this list is passed because the list is not empty.
Example 3: A null object
object = null
The method returns false as the input object points to null.