Java8 streams to find multiple values and return boolean

Question

I am using java-8 to find the values in list of custom object. For ex)

List<Employee> employees = Arrays.asList(
        new Employee("Sachin Tendulkar", 41),
        new Employee("Sachin Tendulkar", 36),
        new Employee("MS Dhoni", 34),
        new Employee("Rahul Dravid", 40),
        new Employee("Lokesh Rahul", 25),
        new Employee("Sourav Ganguly", 40)
);

To find a value in a list i can use the below query,

boolean isPresent = employees.stream()
            .allMatch(employee -> (equalsIgnoreCase(employee.getName(),"Sachin Tendulkar") && equalsIgnoreCase(employee.getAge(),"36")));

The above is working fine. But I would like to find "Sachin Tendulkar" with Age 36 and "Rahul Dravid" with 40. How to achieve this in Java8 streams. I have tried multiple "allMatch" but that doesn't work.

Any hint would be appreciable.

you want to get the employee or check just if it is exist or not? — Youcef LAIDANI
– Youcef LAIDANI, Commented Jun 26, 2018 at 21:58

Youcef LAIDANI · Accepted Answer · 2018-06-26 22:03:43Z

17

You can use anyMatch like so :

boolean isPresent = employees.stream()
        .anyMatch(employee ->
                (employee.getName().equalsIgnoreCase("Sachin Tendulkar") && employee.getAge() == 36)
                        ||
                        (employee.getName().equalsIgnoreCase("Rahul Dravid") && employee.getAge() == 40)
        );

To get the Employee list you can use :

List<Employee> result = employees.stream()
        .filter(employee ->
                (employee.getName().equalsIgnoreCase("Sachin Tendulkar") && employee.getAge() == 36)
                        ||
                        (employee.getName().equalsIgnoreCase("Rahul Dravid") && employee.getAge() == 40)
        ).collect(Collectors.toList());

Or you can create a List of Employee that you want to find and just use List::containsAll, note you have to override hashCode and equals method in your Employee class :

List<Employee> listToFind = Arrays.asList(
        new Employee("Sachin Tendulkar", 36),
        new Employee("Rahul Dravid", 40)
);

boolean isPresent = employees.containsAll(listToFind);

edited Jun 26, 2018 at 22:03

answered Jun 26, 2018 at 21:42

Youcef LAIDANI

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4 Comments

VelNaga Over a year ago

I have override hashcode and equals but still the "containsAll" doesn't works for me

Youcef LAIDANI Over a year ago

@VelNaga how you override it and what you do exactly check this ideone demo for more details :)

VelNaga Over a year ago

I have used intellij equals and hashcode template to override the beans

Youcef LAIDANI Over a year ago

@VelNaga I use the same IDE did you tried my code in the ideone link?

Ravindra Ranwala · Accepted Answer · 2018-06-27 02:33:04Z

5

Here's a more readable solution,

Predicate<Employee> p1 = e -> e.getName().equals("Sachin Tendulkar") && e.getAge() == 36;
Predicate<Employee> p2 = e -> e.getName().equals("Rahul Dravid") && e.getAge() == 40;
final boolean isFound = employees.stream().filter(p1.or(p2)).findAny().isPresent();

A more condensed solution would be,

final boolean isFound = employees.stream().anyMatch(p1.or(p2));

answered Jun 27, 2018 at 2:33

Ravindra Ranwala

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