Replace Optional.get with Optional::orElseThrow

[yeikel]

Java 10 recommends orElseThrow instead of get:

https://docs.oracle.com/javase/10/docs/api/java/util/Optional.html#get()

Some background:

http://mail.openjdk.java.net/pipermail/core-libs-dev/2016-April/040531.html

val value = Optional.of("").get();

val value = Optional.of("").orElseThrow(NoSuchElementException::new);

[timtebeek]

Might fit better in rewrite-migrate-java, due to the minimum Java version.

[yeikel]

Might fit better in rewrite-migrate-java, due to the minimum Java version.

Both methods were introduced in Java 8 but the recommendation started in Java 10 after long discussions on the Java user list. I wouldn't consider this a requirement on a specific version though

Using this pattern in Java 8 is not flagged at the Java docs but it is still dangerous and a bad practice

To me, this recipe can and should also be applied in Java 8 codebases

[jkschneider]

I would add that in 10+ simplify to orElseThrow()?