Java Stream anyMatch()

Java Stream anyMatch(predicate) is terminal short-circuit operation. It is used to check if the stream contains at least one element whic satisfies the given predicate.

1. Stream anyMatch() Method

1.1. Syntax

Here predicate a non-interfering, stateless Predicate to apply to elements of the stream.

The anyMatch() method returns true if at least one element satisfies the condition provided by predicate, else false.

boolean anyMatch(Predicate<? super T> predicate)

1.2. Description

• It is a short-circuiting terminal operation.
• It returns whether any elements of this stream match the provided predicate.
• May not evaluate the predicate on all elements if not necessary for determining the result. Method returns true as soon as first matching element is encountered.
• If the stream is empty then false is returned and the predicate is not evaluated.
• The difference between allMatch() and anyMatch() is that anyMatch() returns true if any of the elements in a stream matches the given predicate. When using allMatch(), all the elements must match the given predicate.

2. Java Stream anyMatch() Examples

Example 1: Java program to check if stream contains a specific element

In this Java example, we are using the anyMatch() method to check if the stream contains the string "four".

As we see that the stream contains the string, so the output of the example is true.

import java.util.stream.Stream;

public class Main 
{
	public static void main(String[] args) 
	{
		Stream<String> stream = Stream.of("one", "two", "three", "four");
		boolean match = stream.anyMatch(s -> s.contains("four"));
		System.out.println(match);
	}
}

Program output.

true

Example 2: Stream anyMatch() with multiple predicates

To satisfy multiple conditions, create a composed predicate with two or more simple predicates.

In the given example, we have a list of Employee. We want to check if there is any employee who is above the age of 50 – is earning above 40,000.

In the list, employee "D" and "F" are earning above 40k and their age is above 50, so the result is true.

import java.util.ArrayList;
import java.util.List;
import java.util.function.Predicate;
import java.util.stream.Stream;
import lombok.AllArgsConstructor;https://howtodoinjava.com/wp-admin/tools.php
import lombok.Data;

public class Main 
{
	public static void main(String[] args) 
	{
		Predicate<Employee> olderThan50 = e -> e.getAge() > 50;
		Predicate<Employee> earningMoreThan40K = e -> e.getSalary() > 40_000;
		Predicate<Employee> combinedCondition = olderThan50.and(earningMoreThan40K);
		
		boolean result = getEmployeeStream().anyMatch(combinedCondition);
		System.out.println(result);
	}
	
	private static Stream<Employee> getEmployeeStream()
	{
		List<Employee> empList = new ArrayList<>();
		empList.add(new Employee(1, "A", 46, 30000));
		empList.add(new Employee(2, "B", 56, 30000));
		empList.add(new Employee(3, "C", 42, 50000));
		empList.add(new Employee(4, "D", 52, 50000));
		empList.add(new Employee(5, "E", 32, 80000));
		empList.add(new Employee(6, "F", 72, 80000));
		
		return empList.stream();
	}
}

@Data
@AllArgsConstructor
class Employee 
{
	private long id;
	private String name;
	private int age;
	private double salary;
}

Program output.

false

3. Difference between anyMatch() vs contains()

Theoretically, there is no difference between anyMatch() and contains() when we want to check if an element exist in a List.

In some cases, parallelism may bring an advantage for really large lists, but we should not casually use the Stream.parallel() every time and there assuming that it may make things faster.

In fact, invoking parallel() may bring down the performance for small streams.

4. Conclusion

The anyMatch() method can be useful in certain cases where we need to check if there is at least one element in the stream.

The shorter version list.contains() also does the same thing and can be used instead.

Happy Learning !!