# Use Optional::ifPresentOrElse
# Description
It is common to have an else-statement following an Optional.isPresent check.
One of the extensions of the Optional API in Java 9 is Optional.ifPresentOrElse (opens new window), which performs either a Consumer or a Runnable depending on the presence of the value.
This rule replaces an isPresent check followed by an else-statement with a single ifPresentOrElse invocation.
Requirements
Java 9
# Benefits
Improves readability and enables the use of higher order funtions on Optional.
# Tags
# Code Changes
# Default
Pre
if(optional.isPresent()) {
String value = optional.get();
consume(value);
} else {
consume("No value");
}
Post
optional.ifPresentOrElse(value -> consume(value), () -> consume("No value"));
# Multiple Statements Lambda Body
Pre
Optional<User> optional = findById(id);
if(optional.isPresent()) {
User user = optional.get();
consume(user);
consume(user);
} else {
System.out.println();
noUserFound();
}
Post
Optional<User> optional = findById(id);
optional.ifPresentOrElse(user -> {
consume(user);
consume(user);
}, () -> {
System.out.println();
noUserFound();
});
# Limitations
Can not be applied if the then path of the branch contains a non-effectively final variable or contains unhandled exceptions. E.g.:
int i = 0;
i++;
if(optional.isPresent()) {
String value = optional.get();
consume(value);
i++;
} else {
consume("No value");
}
Use a Java Refactoring Tool
No license required
You can review this refactoring on your code without a license by installing jSparrow to your Eclipse IDE. Install the plug-in from Eclipse IDE: Eclipse Marketplace.
System-wide Refactoring
Do you want to automate this refactoring (and many more) to your system-wide code? The automatic application of this system-wide refactoring can be unlocked by acquiring your jSparrow license.
# Properties
| Property | Value |
|---|---|
| Rule ID | OptionalIfPresentOrElse |
| First seen in jSparrow version | 3.10.0 |
| Minimum Java version | 9 |
| Remediation cost | 2 min |