How to Perform Advanced Sorting in Java 8

How can I perform advanced sorting using Java 8 features?

List<String> names = Arrays.asList("John", "Jane", "Alice", "Bob");

// Advanced sorting in Java 8 using Streams
List<String> sortedNames = names.stream()
    .sorted(Comparator.comparing(String::length).reversed())
    .collect(Collectors.toList());
System.out.println(sortedNames); // Output: [Alice, John, Jane, Bob]

Java 8 introduced several powerful features, including the Stream API, which makes it easier to handle collections of data and execute operations like sorting. This guide will help you master advanced sorting techniques using Java 8.

List<Employee> employees = Arrays.asList(
    new Employee("John", 3000),
    new Employee("Jane", 4000),
    new Employee("Alice", 3500)
);

List<Employee> sortedEmployees = employees.stream()
    .sorted(Comparator.comparing(Employee::getSalary).reversed()
    .thenComparing(Employee::getName))
    .collect(Collectors.toList());
System.out.println(sortedEmployees); // Sorted by salary (desc) and name (asc)

Causes

• Need for sorting by multiple criteria.
• Sorting collections of objects.
• Improving readability with lambda expressions.

Solutions

• Use the Stream API for flexible sorting.
• Implement custom comparators for sorting complex objects.
• Leverage lambda expressions for concise code.

Mistake: Not using the correct comparator for sorting.

Solution: Ensure that your comparator handles all the sorting criteria in the correct order.

Mistake: Forgetting to collect the results after sorting.

Solution: Always use .collect(Collectors.toList()) to gather the results after using stream operations.