Java chained predicates – logical AND and logical OR operations

Java examples of chained predicates and to perform ‘logical AND‘ and ‘logical OR‘ operations and collect the elements into a list.

1. Predicate.and() – Logical AND example

In given example, we have used Predicate.and() method which returns a composed predicate that represents a short-circuiting logical AND of this predicate and another.

When evaluating the composed predicate, if first predicate is false, then the other predicate is not evaluated.

Any exceptions thrown during evaluation of either predicate are relayed to the caller; if evaluation of first predicate throws an exception, the other predicate will not be evaluated.

import java.util.Arrays;
import java.util.List;
import java.util.function.Predicate;
import java.util.stream.Collectors;

public class Main 
{
	public static void main(String[] args) 
	{
		List<Employee> employeesList = Arrays.asList(
											new Employee(1, "Alex", 100),
											new Employee(2, "Brian", 200),
											new Employee(3, "Charles", 300),
											new Employee(4, "David", 400),
											new Employee(5, "Edward", 500),
											new Employee(6, "Frank", 600)
										);
		
		Predicate<Employee> idLessThan4 = e -> e.getId() < 4;
		
		Predicate<Employee> salaryGreaterThan200 = e -> e.getSalary() > 200;

		List<Employee> filteredEmployees = employeesList.stream()
								.filter( idLessThan4.and( salaryGreaterThan200 ) )
								.collect(Collectors.toList());

		System.out.println(filteredEmployees);
	}
}

Program output.

[Employee [id=3, name=Charles, salary=300.0]]

2. Predicate.or() – Logical OR example

In given example, we have used Predicate.or() method which returns a composed predicate that represents a short-circuiting logical OR of given predicate and another predicate.

When evaluating the composed predicate, if first predicate is true, then the other predicate is not evaluated.

Any exceptions thrown during evaluation of either predicate are relayed to the caller; if evaluation of first predicate throws an exception, the other predicate will not be evaluated.

import java.util.Arrays;
import java.util.List;
import java.util.function.Predicate;
import java.util.stream.Collectors;

public class Main 
{
	public static void main(String[] args) 
	{
		List<Employee> employeesList = Arrays.asList(
											new Employee(1, "Alex", 100),
											new Employee(2, "Brian", 200),
											new Employee(3, "Charles", 300),
											new Employee(4, "David", 400),
											new Employee(5, "Edward", 500),
											new Employee(6, "Frank", 600)
										);
		
		Predicate<Employee> idLessThan2 = e -> e.getId() < 2;
		
		Predicate<Employee> salaryGreaterThan500 = e -> e.getSalary() > 500;

		List<Employee> filteredEmployees = employeesList.stream()
								.filter( idLessThan2.or( salaryGreaterThan500 ) )
								.collect(Collectors.toList());

		System.out.println(filteredEmployees);
	}
}

Program output.

[Employee [id=1, name=Alex, salary=100.0], 
Employee [id=6, name=Frank, salary=600.0]]

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