Cześć!

Od jakiegoś czasu zrobiłem się dużo mocniej aktywny w mediach społecznościowych, szczególnie na Instagram i Facebook.

W ramach tej aktywności zacząłem nagrywać video na temat antywzorców i pułapek dotyczących Stream i Optional w Javie.

Wczoraj wypuściłem właśnie 2 odcinek, który możesz obejrzeć TU. Jak wejdziesz z tego linka na mój kanał YT to znajdziesz też poprzedni odcinek.

Wiem, że jestem tu mało aktywny, ale doszedłem do wniosku, że jednak chyba wolę formę video, dlatego zapraszam Cię na wspomniane media (pozostałe możesz znaleźć na SocialsHub).

Video #3 — Różnica między lambda a referencją do metody
Video #2 — Streamy specjalizowane
Video #1 — strukturalne użycie Optional

Pozdrawiam serdecznie! :)


Cześć! W 2014 zacząłem prowadzić szkolenia stacjonarne. Obecnie mam pewien pomysł na ciekawy (moim zdaniem) kurs video z jednego z tematów w Javie — Stream, Optional i tematy pokrewne. Docelowo takich kursów miałoby powstać kilka. Jak na razie wybrałem temat pierwszego i chciałbym zweryfikować potencjalne zainteresowanie.

Proszę Cię o 5–10 minut Twojego czasu na zapoznanie się ze szczegółami i wypełnienie ankiety, o tu: https://forms.gle/UCnnPTSPDwTRFuAV8
Na przełomie listopada i grudnia zapadnie decyzja co dalej :)

Dzięki, pozdrawiam i do usłyszenia.


Here you can see my upcoming and past trainings and speaking events.

Upcoming

2019–01–28 — Android II @ JSystems [Wroclaw, Poland]

Past

2018

2018–11–19 — Android I @ JSystems [Wroclaw, Poland]
2018–09–17 — Java Basics & Android development introduction @ JSystems [Wroclaw, Poland]
2018–06–25 — Spring MVC & Hibernate @ JSystems [open training in Warsaw, Poland]
2018–06–04 — Android basics @ JSystems [closed training in Wloclawek, Poland]
2018–05–21 — Advanced Java @ JSystems [open training in Warsaw, Poland]

2017

2017–11–20 — Advanced Java + Java8 new features @ JSystems [closed training in Wroclaw, Poland] 2017–11–06 — Advanced Java + Java8 new features @ JSystems…


There were several visions in my head about how I would run my own blog on what I would post about. Finally, I ended up on Medium, just writing posts as a classic Medium user.

Everything was really fine with that approach until…

First problems

During my attempts to make my posts more visible to a community I put my Medium profile RSS feed on jvm-bloggers (polish JVM blogs aggregator).

Not so long after that, I wrote a comment on someone else post on Medium. I was really surprised to see this comment in the jvm-bloggers RSS feed and theirs weekly newsletter…


Image for post
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https://pixabay.com/en/email-marketing-online-marketing-2362038/

This story was originally published on codeburst.io. I moved it here to include it also in my blog publication.

When I was preparing one of my Spring Boot projects to go live, I faced with the problem how to get notified about the errors that might appear in the production environment. Based on my Android development experience I tried to find something like Crashlytics — you just put a simple dependency in the application, put the access key in configuration, all errors are reported to their backend and you get notified by email or by push notification on your mobile…


Image for post
Image for post
https://pixabay.com/en/email-marketing-online-marketing-2362038/

When I was preparing one of my Spring Boot projects to go live, I faced with the problem how to get notified about the errors that might appear in the production environment. Based on my Android development experience I tried to find something like Crashlytics — you just put a simple dependency in the application, put the access key in configuration, all errors are reported to their backend and you get notified by email or by push notification on your mobile phone. I found literally nothing!

How to get notified about the errors that might appear on production environment?

I…


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https://pixabay.com/en/despaired-businessman-business-2261021/

About 2 months ago my client sent me the credentials for brand new VPS machine on which he wanted to migrate a backend for the mobile app. There was a requirement that we can’t just replace DNS entry some weekend to simply make Android application to connect with new server. Client wanted separate environment on the new server, so connecting old database to services on the new server wasn’t possible. In the other way I wouldn’t had any problems with data migration.

First he wanted only a small group of users to be moved to new server instance to test…


The problem

Some time ago I had to configure IPTABLES on a server which acts as the APN gateway for mobile phones used by my client. All traffic comes through this server and is filtered using IPTABLES service.

One of the required services which had to be available is crashlytics.com. I quickly figured out that simple rule below is not enough.

-A FORWARD -s xx.xx.xx.xx -d settings.crashlytics.com -j ACCEPT

Why’s that?

The reason is really simple. When you put a domain in -d parameter IPTABLES will resolve this domain against DNS and put resolved IP address in the place of the domain. …

Paweł Urban

Senior Java Developer | DevOps enthusiast | Freelancer | Trainer

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