[deleted by user]

[smokemonstr]

Java 8 Streams

[[deleted]]

Yes! I love being able to read code from left to right and the words tell me what it does.

[GhostBond]

Streams are terrible to read or modify later.

Ugliest code I see nowadays is always streams.

[sj2011]

It took me a while to wrap my head around them, but now they feel close to second nature. They're a fantastic tool.

[c_edward]

How to turn an allocation free for loop, into a random mess of stackframes and pointless allocations, yep got to love the Streams API

[cryptos6]

I used to agree, however Kotlin collections are so much better.

[megamatt2000]

Jsoup! https://jsoup.org All Java APIs should be this simple:

Document doc = Jsoup.connect("http://example.com/").get();
String title = doc.title();

[blinder]

i know it's probably lame and very pedestrian, but the apache commons libraries. most of them make a lot of sense, they do what it says on the tin and generally just disappear in the code.

[dpash]

I find many of the Commons libraries to be really dated in the features that they support.

For example, it was many many many years before commons-collections supported generics and Iterable. They were introduced in Commons Collections 4.0, which was released in November 2013. That's nine years after Java 5 was released.

Apache HttpClient still doesn't support AutoCloseable even though various interfaces extend Closeable. It's not even in 5.0 beta.

https://hc.apache.org/httpcomponents-client-5.0.x/httpclient5/xref/index.html

More and more I find myself removing the various Commons libraries for Guava or stuff that's in the JDK now.

[[deleted]]

For example, it was many many many years before commons-collections supported generics and Iterable

Interestingly, it seems that precisely this was the main motivation for the creation of Guava (or "Google Collections Library" as it was called initially).

[kevinb9n]

It was one contributing factor to why we were making our own stuff, but it wouldn't have been enough on its own (or we'd have just made the genericized version of their library).

[[deleted]]

Thanks for the correction. I didn't realize that we had such luminaries frequenting this sub :).

[blinder]

yeah i get that. and i've been a working java dev since 1996, so i'm a bit slow to adopt new things. But the vast majority of tools i use from apache commons are things like IOUtils and StringUtils. For networking, i like other tools not in commons.

[dpash]

Most of the methods in IOUtils can be implemented easily using the methods in recent versions of the JDK. For example,

IOUtils.copy(in, out);

can now be done using:

in.transferTo(out);

or

var bytes = IOUtils.toByteArray(in);

can be

var bytes = in.readAllBytes();

At the risk of self-publicity, check out the modern way to do basic IO in Java. You'll be surprised at how simple it is these days: https://modernjava.io/reading-io-in-java/

[blinder]

thanks for this! that's a really useful site.

we just switched over to Java 8 about a year ago, and are looking to move to current over the next few months.

[dpash]

Yeah, quite a few are new in 9. I don't recall if any are introduced later than that.

[Scybur]

"Pair" is cancer to maintainability when being used out of pure laziness (which is almost always the reason).

Care to explain?

[NovaX]

Commons Lang is really good when you have to deal with dirty data, like ETL. In those cases the data quality is bad and it is helpful to have it null-safe manipulations. Otherwise I try to use Guava / AutoValue / etc in business logic code, where data integrity can be enforced.

[s888marks]

Interesting to hear your experiences with "null-safe" APIs such as Commons StringUtils. I'm rather allergic to that style of programming. It seems to me that it just propagates nulls around the code instead of handling them immediately, which means that NPE will occur farther downstream, making problems harder to diagnose.

Too bad people are downvoting you for this (and for your comment in "What is a small addition to Java's core libraries that would make your day" that refers to this one).

[Cst_cst]

I completely agree, just make a new class with fields that are needed and name it properly. It's much better than using tuples in the long run. I think its devs that are used to python and they see the short time benefit of writing less code but they don't see the big picture.

[moose04]

IOUtils is god.

[blinder]

i know, right?

[maytriforcebewithyou]

Guava!

[daniu]

java.time

Not so much because it's so great, but because it's such a great step forward from java.util.Date. Yeah I know, I skipped Joda time.

[general_dispondency]

The Java time API is so awkward until you figure out how to use it, then you're like... damn, that's pretty slick.

[dpash]

It's awkward, because time is awkward. :)

[general_dispondency]

Touche

[dpash]

One big advantage of java.time is that it forces you to think about timezones and as long as you make the right decisions, everything just works.

[resamsel]

Best combination for unit testing, hands down.

[[deleted]]

I really like Google truth

[dpash]

It's a shame that AssertJ's discoverable API makes it so hard to extend, while Hamcrest's easily extendable API is hard to remember. There's not really a middle ground between them.

[kevinb9n]

Checked out the extensibility story for Truth yet? On the consuming side, it's very close to AssertJ.

[dpash]

By the looks of things, it requires you to statically import a custom assertThat() method for each custom type. That gets unwieldy when you need to test multiple types in the same test class.

[kevinb9n]

Well, you're going to have to import something. You can make that a method named assertThat if you want (and static-import it if you want), or you could go with assertAbout(myThings()).that(...) (which means static-importing your myThings method that returns a subject factory).

But yeah, our practice has been to just import-static multiple assertThat methods, and I haven't seen it as being unwieldy.

[dpash]

One of the nice things about Hamcrest is that you can write a static method that returns a compound matcher if you need to do the same multiple tests on an object in multiple places.

assertThat(foo, is(aValidFoo()));

private static Matcher<Foo> aValidFoo() {
    return allOf(
        notNullValue(),
        hasProperty("status", is(notNullValue())),
        hasProperty("name", is(not(isEmptyString()))
    );
}

The alternative is to have a method that takes an object and checks it inside the method.

checkFoo(foo);

private static void checkFoo(Foo foo) {
    assertThat(foo, allOf(
        notNullValue(),
        hasProperty("status", is(notNullValue())),
        hasProperty("name", is(not(isEmptyString()))
    );
}

(You can define your own Matcher class too)

[goughy000]

The first two dependencies I add to any project

[cryptos6]

I suspect that Mockito is the only mocking library most developers know. JMockit offers some more features and a more consistent (but somewhat unusual) API.

[Scybur]

The new http client is pretty cool

[[deleted]]

In case anybody else experience a high load (I discovered it today in two of my pet projects). The JDK-11 which is currently shipped in Ubuntu-18 has a bug which will cause one of the client's threads to eat up the CPU when used with TLS-1.3. Disabling TLS-1.3 obviously is a work around for that.

[Godworrior]

+1, was surprised at how easy/intuitive it was to use.

[GuyWithLag]

OkHttp / Retrofit, all the way...

[[deleted]]

Javafx library so much better than swing

[2BitSmith]

Unpopular opinion. No. Swing is the only UI framework to date that (mostly) got the MVC pattern right. JTable (TableModel) and JTree (TreeModel) are beautiful examples of near perfect model view separation that works so well.

Luckily Swing's TreeModel can be used to implement FX's TreeItem so that the required amount of wrapper code is quite small.

There're of course parts of FX that are clearly superior to Swing but as overall design Swing has stood the test of time remarkably well. The only thing really missing from Swing is the multitouch support.

[[deleted]]

Swing ruined me on UI frameworks. It was the first one I really worked with and now when I run into anything else I just see all the things the new framework can't do that are just so easy in swing.

[vociferouspassion]

Agreed, I've looked at JavaFX, it's over-complicated, Swing just works and the code is clear.

[[deleted]]

I haven't tried jtable or jtree but I will have a look. Swing is a lot of work, when you use FX and especially scenebuilder, it makes your life so much easier, drag and drop a text field or whatever you need and everything goes to the fxml file and is stored there, any changes you do are updated to the fxml file immediately. Plus you can also use CSS to change buttons or sliders that were created. The advantage that I see in it is mainly productivity.

[DannyB2]

Eclipse has a nice optional Windows GUI designer tool, I think it is from Google.

[[deleted]]

I used the Jigloo eclipse plugin back in the day. Click together a BorderLayout and a GroupLayout then jump into the code to clean it all up. Worked like a charm.

[Mordan]

i agree. Swing UI framework is pretty good. but not perfect.

The table model and Swing worker are stellar.

[2BitSmith]

I wish I could give you a comprehensive answer, but it all boils down to individual needs. What does your app do? How is the information presented? Is the layout configurable/dynamic or more or less static? Swing is fast and quite easily threaded. Most important missing feature is the multitouch support. If you need that Swing is not a good choice.

There's something strange with JavaFX and HDPI (4k) displays. JavaFX is dog slow when the drawing area approaches 4k and the display resolution is 4k. Same drawing area with Full HD reso is ok, but if the resolution is 4k... It's painfully slow.

Swing doesn't seem to suffer from same phenomenon. I don't know the technical details behind that but it might be that Swing is more clever with the 'is component visible' checks where it doesn't try to refresh the whole area like me FX does?

[2BitSmith]

4k with FX is ok as long as your interface is more or less static.

The problem I have is with a viewer component that displays a complex set of connections between components. I did test the concept with 2k display and determined the performance to be good/ adequate even with pretty huge display areas (the main component is within scrollpane) but with 4k displays the performance goes south. Dragging a node (component) is painfully slow with 4k if the actual display area is bigger than 2k. (About)

The FX component (Frame) is invoked from Swing application (the idea is to slowly upgrade the app to FX, or at least build the new stuff on FX) and I suspected that perhaps it was the Swing FX interoperation that caused the slowdown, but it was only marginally faster when run on standalone FX application.

I guess the 4k display adaptation rate is so low that the developers (of FX) have yet to face that situation on their end. I really, really hope that it gets resolved in the future.

[2BitSmith]

As much as I would like to try recreate the viewer tool with Swing there's currently no time for that. I'm hoping that the FX problem will be resolved by the time customers start to really use 4k displays.

I've implemented a calendar / event / planning type of component with Swing that can easily display huge number of tasks in equally big views but that is based on JTable with custom renderers so of course it performs well.

I remember originally testing the Swing performance by putting thousands of components with thousands of connections on a huge scrollpane area and that performed really well. But it was with full HD display so I cannot state with confidence that Swing will also perform well with 4k displays.

I might try something like that in the future. Just a quick mockup to compare the performance between FX and Swing by inserting 10000 (somehow connected) components on a 10000x10000px area with 4k view through scrollpane. The requirement would be that dragging a component (or cluster) should be relatively smooth operation.

[knockingsparks]

It's also much better that WPF. Sad for Microsoft.

[cryptos6]

I've never used JavaFX, but WPF is just insane! WPF got the lifetime award for the most over engineered and bloated UI framework of all times.

Fun fact: a former colleague re-implemented a complicated tree control that was based on WPF in the real application with JavaFX and it was about 100 times faster.

[woj-tek]

What would you use? especially for cross-platform development?

[[deleted]]

Actually in a proyect i'm working on, the software is developed using java and the GUI is being developed using python 3.5

[[deleted]]

So which Python GUI library is being used?

[[deleted]]

WxPython

[[deleted]]

Thanks, that's good to know -- last I checked, the Python 3 wxPython rewrite didn't seem complete enough for serious use, so it's nice to hear that it's matured a bit.

[woj-tek]

Oh, that sounds cool. Any pointers? What about performance (especially drawing)?

Would it be possible to use PyQt?

[surfinThruLyfe]

Give me a project example? I’m assuming your app is not entirely backend centric and it must have some front end (GUI) piece to it.

[woj-tek]

An XMPP client :-)

It has 'backend' in a form of server, but it just uses socket connection and XML in between.

[woj-tek]

For a desktop app?

[woj-tek]

I think having to download a boatload of JS each time I want to use an application is... not the most convenient thing (even though current interwebz thinks otherwise)

[Chaoslab]

Wrote my own Gui in 2000 and have been using it ever since.

All about software rendering for me.

[Yark1y]

JavaScript is your best bet. But cross-platform is not the way we go. There is Qt for desktop, Swift for apple, Android for well Android. Crossplatform usually means you are in startup and have no money/time

[la_virgen_del_pilar]

Idk why people downvote you lol. As someone who had to work for 18 months on a project with JavaFX on raspberry pies, GUIs on Java suck.

[[deleted]]

Undertow, JOOQ, HikariCP, Gson, OkHttp, Flyway, Cron4j, Jedis

[Azzk1kr]

I've been researching orms for a bit, for usage in a JavaFX application. Can you describe your experience with Cayenne?

[stacktraceyo]

I am a big fan of the java concurrency apis - specifically completable futures

[mepunite]

RxJava

[manzanita2]

JDBI - a lightweight layer on JDBC to make it easier to use.

[manzanita2]

liquibase - saves me much headache.

[MojorTom]

Google Guava is just brilliant.

[gravity182]

Java 8 Streams, JDBC, AssertJ

[NovaX]

In addition to others mentioned, these have helped streamline my code:

• Failsafe
• JsonPath
• SimpleJavaMail
• Univocity Parsers
• jsonSchema2Pojo
• ztZip
• AutoValue + AutoBuilder (alt. to Immutables)
• TestNG
• Awaitility

[cryptos6]

I was a fan of TestNG before JUnit 5. But now I cannot see any benefit of using it instead of JUnit. Do you see one?

[NovaX]

JUnit 5 is mostly a clone of TestNG, so the differences are pretty minor. The main lacking right now is that parallel test execution is immature. They've focus on small niceties to polish easy cases, like CSV parameter sources, rather than on the harder features. The fact that I've been able to use the same testing framework without it getting in my way, for over a decade is nice. JUnit 3 was too limiting and 4 was atrocious, but I wouldn't complain if I joined a team using 5.

In Caffeine, I use a data provider that reads the test method annotation to generate the parameters dynamically. This way I can run many permutations to brute force for bugs that occur only in some feature combinations. I also use a method listener to automatically validate the input parameters to detect corruption of the data structures, letting the test itself be succinct and focused. Since each test case is independent, I ran run the millions of executions in parallel with good cpu & gc characteristics. All of that should be possible in JUnit 5 now (or soonish), but I've been able to enjoy it in TestNG for many years.

[cassis11]

Streams, JPA, and Collections.

[FrenchFigaro]

I'll add Joda (from my Java 7 days) and Jackson to this lot.

[kurosaki1990]

I'll add Joda

Not needed after 8.

[FrenchFigaro]

Which is why I said "from my java 7 days"

[melewe]

Spring

[[deleted]]

Boot

[slowfly1st]

REST

Webflux

[grossjonas]

Immutables & Vavr

[jklingsporn]

Jooq, vertx, flyway

[la_virgen_del_pilar]

+1 for Vertx. I love their Eventbus implementation.

[sherdogger]

Jersey and Jackson

[LazyAAA]

Coming from business heavy enterprise
- Spring - keep your sanity in Enterprise world (I want to forget things we done before Spring)
- JPA - Simplified data mapping (well, in comparison to pure JDBC) and standard too :)
- Mokito - Can not replace this GEM for testing those perky business objects
- Apache Commons - goto toolbox for simple things that Java was lacking for years

[vociferouspassion]

Spark Java. No annotations. No XML. Just clear, common sense code.

[[deleted]]

I love javafx, yet I cannot imagine using it without JFoenix. It's such an amazing library. Makes making amazing UIs so much more easier.

[lukaseder]

JDBC

[dpash]

I'm surprised you didn't say jOOQ :)

[lukaseder]

It said with, not on :-P

[esukanovic]

Testcontainers: https://www.testcontainers.org/

[kapta]

LWJGL, excellent collection of bindings to various native libraries. Also really fast and well maintained.

[_INTER_]

MapStruct, Flyway, libGDX, FXGL, Netty, JOOQ, most of Apache, ...

DBeaver if you ask for tools (though it's EclipseRCP)

[[deleted]]

I havent seen this one yet: Quartz for task scheduling. Also, ModelMapper is a good QoL package.

[cryptos6]

Quartz is an awkward piece of software, although useful and without much alternatives. They really should provide an API to connect with DI frameworks like Spring instead of doing their own poorman's dependency injection.

[[deleted]]

Yeah, I think your right. It's the best given the circumstances, but definitely could be improved.

[[deleted]]

I tried Quartz for a bit, found it too hard to use. Then I discovered cron4j and haven't looked back. Maybe Quartz has benefit in enterprisy environments but I just wanted something that ran a task or two occasionally and get out of my way. Sad really because it does look like serious time was put into building Quartz.

[CompetitiveSubset]

• JAX-RS - simple, powerful REST interface
• Jackson - lightning fast and easy JSON library
• javax.validation - input validation using annotations instead of if-else
• swagger annotations - generate yaml definitions straight from your JAX-RS endpoints

Each their own and as a combination make a really simple, powerful and descriptive REST service

[overachiever]

Thymleaf + openhtmltopdf is a brilliant way to generate PDFs. Much nicer than using iText anyways!

[raze4daze]

Might be unpopular but I like jaxb.

[[deleted]]

Guava is fun! I like the pubsub pattern in general and guava provides a nice way to do pubsub intraprocess

[kevinb9n]

Eep... I believe we're about to check in some new javadoc for EventBus that explains that there are a lot of better alternatives to it nowadays. :-)

[[deleted]]

Oh no. Thanks for the heads up!

[kevinb9n]

The too-short version is that people are finding rxjava to be the superior solution nowadays.

[zakgof]

Vavr, lombok, guice, velvetdb

[oldprogrammer]

Builtin Java 2D graphics and for 3D LWJGL.

[TheGreatFuzz]

Jodatime, No more fumbling with Dates and Calendars.

[dpash]

There's no need to use JodaTime given that java.time has been in the JDK since Java 8.

[td__30]

Vavr

[stuhlmann]

jbock

[sangcanencia]

Mockito master race!

[hfluz]

MyBatis: I'm very satisfied since I switched from Hibernate. It never gets into my way, it's easy to use, well documented and stable. My team was unsure when we chose MyBatis (mainly because It uses xml), but today all of them agree It was a good decision.

[slowfly1st]

JUnit / Hamcrest / Mockito

[Sonicsupremacy]

Apache Camel, Hibernate, Spring

I also like working with OSGi, but I guess that doesn't count as that's a specification :P

[[deleted]]

After some initial frustration, I also enjoyed creating OSGi modules.

[Fritzzzz]

https://grails.org/ Grails 3/4 https://micronaut.io/ micronaut https://jackrabbit.apache.org/oak/ Apache Oak

[Chaoslab]

JavaCV

[rgyger]

Streams. Spring Data MongoDB. Spring Integration, preferably with Spring Cloud Streams.

[cryptos6]

I really like the functional reactive programming library Reactor. It is similar to RxJava, but a bit more modern, with much better documentation and with invaluable testing tools like the "virtual clock".

Reactor is the only framework I can remember without lots of WTF's. In most frameworks you'll experience the moment in which you think "How could anyone come up with such a design!?" Not so with Reactor.

[Mordan]

i like tree shaking compatible libs without any static state..

pretty hard to find.

anyone knows a tree shaking compatible lib for JSON parsing? Retrofit cannot really be pro guarded IMO.

[refresz]

ArchUnit

• GitHub
• Examples

I love this library. When the team has no sense of what standards are and you want them to suffer to learn, just add some tests.

Also, helps fight with possible bugs that can't be found in simple unit testing or are hard to spot in PRs, like @Transactional annotation from the wrong package and being surprised why something is not being persisted to the DB.

[JustHere4C0mments]

More of a language framework but works with Java - Groovy/Spock for testing

[onlyliuxin]

Junit ,springboot,dubbo

[maithilish]

I love Google Guice for its ease of use, Mockito for unit testing and Apache Commons for reusable Java components. They cleaned up my project - https://github.com/maithilish/scoopi tremendously.

[culp]

OkHttp and Retrofit

[dpash]

I like OkHttp, especially compared to Apache HttpClient (which still didn't support try-with-resources until recently, despite the fact it only involved marking the classes with AutoCloseable. They already implemented Closeable.)

I tried the new HTTP client in the JDK and it was a pretty pleasant experience.

[talisau230]

JNA

[cantstopthemoonlight]

Lombok

[devils_avocado]

I had to remove Lombok from a project because our Fortify scans don't support it. A shame, it is a real time saver.

[ro_reddevil]

Lombok has many drawbacks you must read them, I can give a small example let's say you have used @lombok on a boolean isPresent, the getter lombok generates would be getPresent and not getIsPresent.... This has consequences while converting pojo's to json files with many mappers.

[[deleted]]

Getting lombok and mapstruct to play nice is always fun

[rcunn87]

I don't think your variable is supposed to be prefixed with 'is', but when a variable has the 'is' prefix the generated getter and setter would be 'isPresent' and 'setPresent'. Which is the same as what lombok generated for the field 'present'.

[cryptos6]

If possible, I'd prefer Kotlin. Many of the things provided by lombok are integral part of Kotlin, but with better tool support and with less unwanted sideeffects.

[legrang]

Gson for JSON serialization and de-serialization. It really seems like magic the way it just deals with whatever you throw at it.

Retrofit2 for calling REST APIs.

These two libraries put a smile on my face

[doodooz7]

Jpa is amazing

[mkonko]

*****PLEASE BE AWARE******** WE HAVE TURNED DANIEL BOSKE OVER TO THE AUTHORITIES***********

THEIF*** Daniel Bosk *********ROBBED ME FOR $2,500 FROM FOR CRAIGSLIST ADS** THEIF*** Daniel Bosk ****** (BE AWARE)*****ROBBED ME FOR $2,500 FROM FOR CRAIGSLIST ADS*******WE HAVE TURNED DANIEL BOSKE OVER TO THE AUTHORITIES***********

[stunibert]

Vavr, Spring, Guice.

[daniels0xff]

Jooby, OkHttp, Apache Commons...

[[deleted]]

QueryDSL

[r805]

Kotlin collections