How can we sort a list of Transaction objects by date and in case of a tie, sort by ID using Java 8

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Explanation:

In this blog post, we'll explore how to use Java 8's Stream API and Comparator to sort a list of Transaction objects first by their date attribute and then by their id attribute in case of a date tie

Sample Code:

java
public class MultipleComparatorTest {
    private int id;
    private String txnType;
    private String date;

    public MultipleComparatorTest(int id, String txnType, String date) {
        this.id = id;
        this.txnType = txnType;
        this.date = date;
    }

    public int getId() {
        return id;
    }

    public String getDate() {
        return date;
    }
    
    

    @Override
	public String toString() {
		return "MultipleComparatorTest [id=" + id + ", txnType=" + txnType + ", date=" + date + "]";
	}

	public static void main(String[] args) {
        List<MultipleComparatorTest> transactions = createTransactionList(); // Create your list of Transaction objects

        Comparator<MultipleComparatorTest> byDateThenId = Comparator
            .comparing(MultipleComparatorTest::getDate, (date1, date2) -> date2.compareTo(date1))
            .thenComparing(MultipleComparatorTest::getId);

        List<MultipleComparatorTest> sortedTransactions = transactions.stream()
            .sorted(byDateThenId)
            .collect(Collectors.toList());

        // Now, sortedTransactions contains the sorted list of Transaction objects
        sortedTransactions.forEach(System.out::println);
    }

    // Utility method to create a list of Transaction objects
    private static List<MultipleComparatorTest> createTransactionList() {
        // Add your Transaction objects to this list
        // For example:
        List<MultipleComparatorTest> transactions = Arrays.asList(
            new MultipleComparatorTest(1, "Type1", "2023-10-19"),
            new MultipleComparatorTest(3, "Type3", "2023-10-18"),
            new MultipleComparatorTest(2, "Type2", "2023-10-18")
            // Add more transactions
        );

        return transactions;
    }
}

Sample Output:

output
MultipleComparatorTest [id=1, txnType=Type1, date=2023-10-19]
MultipleComparatorTest [id=2, txnType=Type2, date=2023-10-18]
MultipleComparatorTest [id=3, txnType=Type3, date=2023-10-18]