Configuring Tomcat JDBC Connection Pool

In this post about the Tomcat JDBC Connection Pool configuration

A lot of libraries here

Catalog of the open source libraries ( Java, JavaScript, Python...) https://libraries.io/

java.lang.OutOfMemoryError The 8 symptoms that surface them

Tutorial content:
java.lang.OutOfMemoryError: Java heap space
java.lang.OutOfMemoryError: GC overhead limit exceeded
java.lang.OutOfMemoryError: Permgen space
java.lang.OutOfMemoryError: Metaspace
java.lang.OutOfMemoryError: Unable to create new native thread
java.lang.OutOfMemoryError: Out of swap space?
java.lang.OutOfMemoryError: Requested array size exceeds VM limit

Source:

https://plumbr.eu/outofmemoryerror

or

Dropbox link

Instagram API search by tag doesn't return anything

I created new app on instagram and tried to get all images by tag, following api call was used:

/tags/{tag-name}/media/recent.

As a result i received empty list, with message in pagination: depreciationWarning=next_max_id and min_id are deprecated for this endpoint; use min_tag_id and max_tag_id instead.

It took me a while to get that apps in sandbox mode (starting November 2015) has some limitations. Here what documentation says:

"As another example, let's consider an endpoint that returns a list of media: /tags/{tag-name}/media/recent. The response returned by this endpoint will contain only media with the given tag, as expected. But instead of returning media from any public Instagram user, it will return only media that belongs to your sandbox users, restricted to the last 20 for each user."

PS: I used cool library called jInstagram https://github.com/sachin-handiekar/jInstagram

Java SE 8 best practices

Java SE 8 best practices by Stephen Colebourne

Microservices with Spring

Spring cloud is set of tools that helps you to build your application in "Microservice way". Here is short tutorial that spring published. More about microservices in dzone article.

WARNING: Could not initialize OpenglES emulation, using software renderer

When I am running android emulator(from Android studio) I am getting bellow error:

emulator: WARNING: Could not initialize OpenglES emulation, using software renderer

This was due my switchable graphics, so my laptop has two video cards. And by default intel video was used. When I switched to the ATI video everything worked great.