Java 8 refers to the newest version of the Java platform.

learn more… | top users | synonyms

-2
votes
2answers
102 views

Java 8 vs Scala? Which one to learn? [on hold]

Scala has been promoted with advantages of perfect mix of functional programming and pure OOP and some more features which is difficult to achieve with java like reliable multi-thread programming. I ...
0
votes
0answers
9 views

Incomprehensible null problem [migrated]

Can anybody explain why the print-statement within the loop produces an error (Null type mismatch: required '@NonNull SortedSet' but the provided value is specified as @Nullable) and the one outside ...
0
votes
0answers
72 views

Java 8 Streams API HAVING clause equivalent in a GroupingBy? [migrated]

I've run into a hard to solve problem in Streams API. Well, it is solvable but not elegantly within a single call from what I can tell. Below, taking a stream of FeatureContentWeight objects, I want ...
0
votes
2answers
86 views

Java Streams API Documentation

Currently learning Java so this may be a question resulting from lack of understanding of Java (while also learning Streams API) In the declarations of function I often see two templated types for ...
5
votes
3answers
218 views

Does it make sense to split up an existing multi-method interface into several single method interfaces just to take advantage of lambdas?

Say I have an existing callback interface that has multiple methods. To illustrate my point I use a callback the likes that you would see in code that performs some HTTP client operations: public ...
1
vote
2answers
92 views

How the Stream.filter() method works?

I know how the lambda expresion works and I know it is an argument for .filter() that establish the criteria to filter with. But I don't get how .filter() uses the argument, in this case a lambda ...
2
votes
2answers
173 views

Is there any reason not to use Optional as a method argument in the case where you know the argument is something that may or may not be needed?

With Java 8, I've seen more and more articles about the use of Option/Optional. I understand what they trying to represent, and I see many examples of them being used as returns. However what I don't ...
11
votes
4answers
6k views

Why were default and static methods added to interfaces in Java 8 when we already had abstract classes?

In Java 8, interfaces can contain implemented methods, static methods, and the so-called "default" methods (which the implementing classes do not need to override). In my (probably naive) view, there ...
5
votes
1answer
337 views

Passing a Scala function to a Java 8 method

The following Scala code works and can be passed to a Java method expecting a function. Is there a cleaner way to do this? Here's my first pass: val plusOne = new ...
18
votes
2answers
2k views

Workaround for Java checked exceptions

I appreciate a lot the new Java 8 features about lambdas and default methods interfaces. Yet, I still get bored with checked exceptions. For instance, if I just want to list all the visible fields of ...
31
votes
3answers
4k views

Why are the Java 8 java.time classes missing a getMillis() method?

Java 8 has a whole new library for dates and times in the package java.time which is very welcome thing to anyone who has had to use JodaTime before or hassle with making it's own date processing ...
4
votes
2answers
2k views

Are Interfaces with Java 8 Virtual Extension Methods the Same Thing as Mixins?

This post describes a new feature in Java 8 called virtual extension methods (formerly called default methods, or defender methods). In the example provided, an interface has one method, which is ...
1
vote
1answer
227 views

Why would someone use @Native annotations?

link : http://download.java.net/jdk8/docs/api/java/lang/annotation/Native.html In Java 8, there will be @Native annotations. Indicates that a field defining a constant value may be referenced ...
11
votes
1answer
1k views

Reasons for removal of function types in Java 8

I have been trying to understand why the JDK 8 Lambda Expert Group (EG) decided not to include a new function type into the Java programming language. Going over the mailing list I found a thread ...
19
votes
2answers
5k views

Type inference in Java 8

Is the introduction of the new lambda notation (see e.g. this article) in Java 8 going to require some kind of type inference? If so, how will the new type system impact the Java language as a whole? ...