Rewriting Optional without using isPresent

xiwuroke :

void spendTheNight() {
    Optional<Homework> homework = getHomeworkDueTonight();
    if (homework.isPresent()) {
        rushThrough(homework.get());
    } else {
        homework = getHomeworkDueNextWeek();
        if (homework.isPresent()) {
            workSlowlyOn(homework.get());
        } else {
            partyHard();
        }
    }
    goToBed();
}

I know it's bad practice to do if..else with isPresent; how can I rewrite this to make better use of Optional such that the flow of logic stays the same?

I was thinking of using or, orElse, or orElseGet, but not sure how to use them here, with that additional assignment in the first else.

(assume the custom methods can't be modified and must be used as-is)

Naman :

All the listed APIs by you or, orElse, or orElseGet return one or the other value, your code seems to be more around running a stub based on some conditions around return types of the methods.

You can use ifPresentOrElse in such a case, since Java 9:

Optional<Homework> homework = getHomeworkDueTonight(); 
homework.ifPresentOrElse(this::rushThrough, () -> { 
    Optional<Homework> hw = getHomeworkDueNextWeek(); 
    hw.ifPresentOrElse(this::workSlowlyOn, this::partyHard); 
});
goToBed();

Guess you like

Origin http://43.154.161.224:23101/article/api/json?id=296069&siteId=1

Rewriting Optional without using isPresent

'Optional.get()' without 'isPresent()' check

Optional isPresent vs orElse(null)

Call "Optional#isPresent()" before accessing the value

Adding Optional.isPresent() inside Java 8 Comparator

How to replace if(Optional.isPresent()) with an expression in functional style

Calling Optional#isPresent() in single line is reported as not called

MyBatis implements dynamic SQL updates without rewriting

Validating inputs using Optional

Using Optional to avoid NPE

Optional JsonPath using Jayway

How to use groupingBy with reducing without getting an Optional

Initialise class without defining the optional values

Optional<T> when isPresent() get property or null when it is null; functional style in Java 8

Overview of the practice of using Java Optional

Using optional to populate value in a Map

Without using the plus addition

iOS development Swift-8-class inheritance, method rewriting, constructor, enumeration type, optional type, forced unpacking, optional binding, implicit optional type...

abap using code definition method, parameters are optional

Make argument optional using <Void> type?

Multiple null checks using Optional in Java 8

Using Spring mockMvc to test optional path variables

using a stream based on the content of Optional<Map>

Better way for using builder pattern with optional values?

Is there a cleaner way to use Optional here without returning "NA" in three places?

Why is Java 8 Optional implemented as final, without Some and None hierarchy?

Calling method after Optional.filter() without passing in object

Using OpenGL in C#: (9) Rewriting the C# OpenGL interface

Store installed without using WSL

Spring @RequestBody without using a pojo?