All About Programming: August 2019

How to convert ArrayList to HashMap or LinkedHashMap in Java 8 - Example Tutorial | Java67

1) You can use the Function.identity() function if you are passing the object itself in the lambda expression. For example, lambda expression s -> s can be replaced with Function.identity() call.

2) Use the static important feature to import static methods of Collectors e.g. toMap(), this will simplify your code.

3) The toMap(keyExtractor, valueExtractor) doesn't provide any guarantee of what kind of map it will return.

4) If your List contains duplicate elements and you are using them as the key then you should use toMap(keyMapper, valueMapper, mergeFunction). The merge function used to resolve collisions between values associated with the same key, as supplied to Map.merge(Object, Object, BiFunction). See Java SE 8 for Really impatient to learn more about merge() function of Map interface in Java 8.

Read full article from How to convert ArrayList to HashMap or LinkedHashMap in Java 8 - Example Tutorial | Java67

FFmpeg tips - I'm Siegfried. A developer. Yep.

Here are a few commands for FFmpeg that were useful for me.

The help page for all parameters is here.

A nice tool that uses FFmpeg is Handbrake.

Get some info about a file

ffmpeg -i video.mp4

Parameters:

ffmpeg is the ffmpeg command :p
-i video.mp4 specifies the input file

Extract the audio part of a video

ffmpeg -i video.mp4 -vn -acodec copy audio.m4a

Parameters:

-vn disables the video
-acodec copy allows to copy the audio stream without touching it
audio.m4a is the output file

Convert an audio file to another format

ffmpeg -i audio.m4a -acodec libmp3lame -ac 0 -ab 320k audio.mp3

Parameters:

-acodec libmp3lame allows to use the lame mp3 library for conversion
-ac 2 sets the number of channels
-ab 320k sets the bitrate

Of course, the previous command and this one can be merged for a 1 step audio extraction & conversion.

Read full article from FFmpeg tips - I'm Siegfried. A developer. Yep.

"ffplay" Interactive Commands

While playing a movie with the "ffplay", you can also control the playing process using the following interactive commands:

q, ESC            quit  f                 toggle full screen  p, SPC            pause  a                 cycle audio channel in the current program  v                 cycle video channel  t                 cycle subtitle channel in the current program  c                 cycle program  w                 cycle video filters or show modes  s                 activate frame-step mode  left/right        seek backward/forward 10 seconds  down/up           seek backward/forward 1 minute  page down/page up seek backward/forward 10 minutes  mouse click       seek to percentage in file corresponding                     to fraction of width

Let use these interactive commands to locate the ending position of the "Anchor 'Great Escape'" segment.

1. Run "ffplay" to play "Tony_reelshow_2009_512kb.mp4". The movie player starts.

2. Click the player screen at about 22% width position. The player seeks to 00:00:42 position and displays the following on the console:

Seek to 22% ( 0:00:42) of total duration ( 0:03:11)       B f=0/0

3. Press "p" to stop the play. The player displays a still image of the "Anchor 'Great Escape'" segment.

4. Press "s" to step 1 frame forward. The player shows the following on the console:

  42.03 A-V:  0.028 fd=  96 aq=    5KB vq=    9KB sq=    0B f=0/0

5. Press <right> arrow key to seek forward for 10 seconds. The player displays a still image of the next movie segment with the following on the console:

  52.03 A-V:    nan fd=  96 aq=    1KB vq=   19KB sq=    0B f=0/0

6. Press <left> arrow key to seek backward for 10 seconds. Then press "s" many times until you see the last image of the "Anchor 'Great Escape'" segment. It should be at 00:00:43.33.

Read full article from "ffplay" Interactive Commands

Ubuntu – How to install VLC Media Player using terminal – IT Support Guides

The following steps show how to install VLC Media Player using the terminal on Unbutu 16.04.

Click on the Ubuntu icon in the launcher to open the search dialog
Type "terminal" and click on the icon when it appears

Read full article from Ubuntu – How to install VLC Media Player using terminal – IT Support Guides

A quick guide to using FFmpeg to convert media files | Opensource.com

There are many open source tools out there for editing, tweaking, and converting multimedia into exactly what you need. Tools like Audacity or Handbrake are fantastic, but sometimes you just want to change a file from one format into another quickly. Enter FFmpeg.

FFmpeg is a collection of different projects for handling multimedia files. It's often used behind the scenes in many other media-related projects. Despite its name, it has nothing to do with the Moving Picture Experts Group or the myriad multimedia formats it has created.

In this article I'll be using FFmpeg through the command-line tool ffmpeg, which is only a single, small piece of the FFmpeg project. It's available on many different operating systems and is included in some operating systems by default. It can be downloaded from the FFmpeg website or through most package managers.

FFmpeg is a powerful tool that can do almost anything you can imagine with multimedia files. In this article, we are interested in using it to convert files, so we won't be taking a deep dive into its entire feature set. Before we look at using FFmpeg, first we need to take a quick look at what a media file exactly is.

Read full article from A quick guide to using FFmpeg to convert media files | Opensource.com

Can Guice do DI without the @Inject annotation on constructors without real side-effects? · Issue #1079 · google/guice

By default Guice does not require you to annotate your public constructor with @Inject - if there's only one such public constructor then it will automatically pick that one. Even when there are multiple constructors then you can use a constructor binding to tell Guice which one to use and avoid the ambiguity: https://google.github.io/guice/api-docs/latest/javadoc/com/google/inject/binder/LinkedBindingBuilder.html#toConstructor-java.lang.reflect.Constructor- Using @Inject is still recommended for code under your control because it documents that class was written with injection in mind. You can also tell Guice to enforce the existence of @Inject on constructors if you wish: https://google.github.io/guice/api-docs/latest/javadoc/com/google/inject/Binder.html#requireAtInjectOnConstructors--

Read full article from Can Guice do DI without the @Inject annotation on constructors without real side-effects? · Issue #1079 · google/guice

(34) How do I play audio only on YouTube iOS app? - Quora

YouTube iOS app will not let you to do this, but there are ways by which you can listen only audio. Follow these simple steps for listening to YouTube videos while still being able to lock your iPhone screen.

Open Safari on your iPhone.
Go to YouTube and search for the video that you want to listen to. Or if you're logged in, you can access videos from your subscriptions or playlists that you've created.
Tap on the video to begin playing it.
Press down on the Power button to lock your iPhone and turn off the screen. The video will automatically pause just like it does in the YouTube app.
Press down on the Power button again and press the Play button to resume the video (or audio, in this case).
You can now lock your iPhone and the audio will continue to play.

Read full article from (34) How do I play audio only on YouTube iOS app? - Quora

Play audio only on YouTube to save bandwidth - gHacks Tech News

Audio Only YouTube is a browser extension for Google Chrome to play the audio stream of YouTube videos only.

The video hosting site YouTube offers no option to play only the audio track of videos. While that is probably not desirable in many cases, it is beneficial in a few cases.

Playback of the audio stream of a video on YouTube uses less bandwidth than playback of the entire video. This may improve the stream quality, especially on low-end devices or devices with limited Internet bandwidth, for instance, when videos buffer all the time or don't play fluently. Another benefit of it is that audio-only streams require less power than video streams; useful if you connect to YouTube on mobile devices.

Read full article from Play audio only on YouTube to save bandwidth - gHacks Tech News

Scan a QR code with your iPhone, iPad, or iPod touch - Apple Support

Learn how to use the built-in camera on your iPhone, iPad, or iPod touch to scan a Quick Response (QR) code.

QR codes give you quick access to websites without having to type or remember a web address. You can use the Camera app that's built in to your iPhone, iPad, or iPod touch to scan a QR code.

Read full article from Scan a QR code with your iPhone, iPad, or iPod touch - Apple Support

How to Get the Pixel's Feature-Packed Google Camera App on Other Android Devices « Android :: Gadget Hacks

The Pixel is the phone to beat when it comes to cameras, and it's largely due to software. While its hardware is solid, Google's machine learning prowess and general coding wizardry are the biggest reasons the Pixel is so good with taking photos and recording video. What this means is that if you can get the Pixel's camera software, you can replicate the Pixel camera experience on other phones.

Read full article from How to Get the Pixel's Feature-Packed Google Camera App on Other Android Devices « Android :: Gadget Hacks

An Introduction to Programmable Completion

The programmable completion feature in Bash permits typing a partial command, then pressing the [Tab] key to auto-complete the command sequence. [1] If multiple completions are possible, then [Tab] lists them all. Let's see how it works.

bash$ xtra[Tab]  xtraceroute       xtrapin           xtrapproto   xtraceroute.real  xtrapinfo         xtrapreset   xtrapchar         xtrapout          xtrapstats      bash$ xtrac[Tab]  xtraceroute       xtraceroute.real      bash$ xtraceroute.r[Tab]  xtraceroute.real

Tab completion also works for variables and path names.

bash$ echo $BASH[Tab]  $BASH                 $BASH_COMPLETION      $BASH_SUBSHELL   $BASH_ARGC            $BASH_COMPLETION_DIR  $BASH_VERSINFO   $BASH_ARGV            $BASH_LINENO          $BASH_VERSION   $BASH_COMMAND         $BASH_SOURCE      bash$ echo /usr/local/[Tab]  bin/     etc/     include/ libexec/ sbin/    src/        doc/     games/   lib/     man/     share/

The Bash complete and compgen builtins make it possible for tab completion to recognize partial parameters and options to commands. In a very simple case, we can use complete from the command-line to specify a short list of acceptable parameters.

bash$ touch sample_command  bash$ touch file1.txt file2.txt file2.doc file30.txt file4.zzz  bash$ chmod +x sample_command  bash$ complete -f -X '!*.txt' sample_command      bash$ ./sample[Tab][Tab]  sample_command  file1.txt   file2.txt   file30.txt

Read full article from An Introduction to Programmable Completion

Creating a bash completion script

In this post I will familiarize you with the process of adding bash completion to your scripts.

What is bash completion?

Bash completion is a functionality through which bash helps users type their commands faster and easier. It accomplishes that by presenting possible options when users press the tab key while typing a command.

$ git<tab><tab>  git                 git-receive-pack    git-upload-archive    gitk                git-shell           git-upload-pack       $ git-s<tab>  $ git-shell  

How it works

The completion script is code that uses the builtin bash command complete to define which completion suggestions can be displayed for a given executable. The nature of the completion options vary from simple static to highly sophisticated.

Why bother

It is good to provide such a functionality to users:

to save them from typing text when it can be auto-completed
to help them know what are the available continuations to their commands
to prevent errors and improve their experience by hiding or showing options based on what they have already typed

Read full article from Creating a bash completion script

BASH Autocompletion - Stuff… And Things…

A couple of posts back, I showed off some functions to pop up notifications when a host became pingable again or when a port became reachable. Today's (semi) quick tip is how to use BASH's autocomplete functionality add hostname autocompletion to those notifications functions.

BASH autocompletion is a system that provides tab completion of command arguments. You're familiar with it's default behavior which is to complete filenames and paths.

~ ls enctypt<TAB>  encrypt              encrypt-only-sym.rb  encrypt-time.rb  encrypt-decrypt.rb   encrypt-sym.rb       encrypt.rb  ~  ls encrypt

You can override this behavior by providing BASH with a list of possible completions. The list can be a literal list of words, or it can be a function that looks at the current environment ($PWD, user, time on day, etc) and generates context aware list.

Bash hostname completion | Arabesque

As part of its programmable completion suite, Bash includes hostname completion. This completion mode reads hostnames from a file in hosts(5) format to find possible completions matching the current word. On Unix-like operating systems, it defaults to reading the file in its usual path at /etc/hosts.

For example, given the following hosts(5) file in place at /etc/hosts:

127.0.0.1      localhost  192.0.2.1      web.example.com www  198.51.100.10  mail.example.com mx  203.0.113.52   radius.example.com rad

An appropriate call to compgen would yield this output:

$ compgen -A hostname  localhost  web.example.com  www  mail.example.com  mx  radius.example.com  rad

We could then use this to complete hostnames for network diagnostic tools like ping(8):

$ complete -A hostname ping

Typing ping we and then pressing Tab would then complete to ping web.example.com. If the shopt option hostcomplete is on, which it is by default, Bash will also attempt host completion if completing any word with an @ character in it. This can be useful for email address completion or for SSH username@hostname completion.

Read full article from Bash hostname completion | Arabesque

notify-send Man Page - Linux - SS64.com

A program to send desktop notifications, inform the user about an event or display some form of information without getting in the user's way.

Syntax         notify-send [OPTIONS] [body]     Key     -u, --urgency=LEVEL                 The urgency level (low,  normal,  critical).        -t, --expire-time=TIME                 The  timeout in milliseconds at which to expire the                 notification.        -i, --icon=ICON[,ICON...]                 An icon filename or stock icon to display.        -c, --category=TYPE[,TYPE...]                 Specifies the notification category.        -?, --help                 Show a help message        -h, --hint=TYPE:NAME:VALUE                 Pass extra data. Valid TYPEs are int, double, string and byte.

To use notify-send, you might need to install the following package:
$ sudo apt-get install libnotify-bin

Examples

$ notify-send "Hello World"

$ notify-send -t 5000 -u low "Hello World"

Read full article from notify-send Man Page - Linux - SS64.com

Ubuntu & Debian Cookbook: Howto: Sync Bash History Between Terminals

Do you want to be able to use the history from another terminal quickly and simply in a new terminal, or to be able to use any one of the terminals on your desktops to continue working with a current history?

Me too :]

This is a very easy tweak and makes a lot of sense to most people. So we need to edit the file ~/.bashrc

gedit ~/.bashrc

At the bottom paste in the following:

shopt -s histappend PROMPT_COMMAND="history -n; history -a" unset HISTFILESIZE HISTSIZE=2000

Unsetting HISTFILESIZE just gets rid of the filesize limitation, and we rely on HISTSIZE which allows 2000 lines in the file, both normally default to 500.

PROMPT_COMMAND tells bash to reload history and append to history each time it draws the prompt in the terminal.

The only thing to note is if you jump from one terminal to another and wish to recall the last history line from the former terminal, press enter once with a blank line, this causes bash to draw the prompt and sync, if you only just opened the second terminal then you don't have to. The sync only occurs when the prompt is drawn, nothing else to note.

Read full article from Ubuntu & Debian Cookbook: Howto: Sync Bash History Between Terminals

Bash hostname completion | Arabesque

For example, given the following hosts(5) file in place at /etc/hosts:

127.0.0.1      localhost  192.0.2.1      web.example.com www  198.51.100.10  mail.example.com mx  203.0.113.52   radius.example.com rad

An appropriate call to compgen would yield this output:

$ compgen -A hostname  localhost  web.example.com  www  mail.example.com  mx  radius.example.com  rad

We could then use this to complete hostnames for network diagnostic tools like ping(8):

$ complete -A hostname ping

We could also trigger hostname completion in any other Bash command line (regardless of complete settings) with the Readline shortcut Alt+@ (i.e. Alt+Shift+2). This works even if hostcomplete is turned off.

However, with DNS so widely deployed, and with system /etc/hosts files normally so brief on internet-connected systems, this may not seem terribly useful; you'd just end up completing localhost, and (somewhat erroneously) a few IPv6 addresses that don't begin with a digit. It may seem even less useful if you have your own set of hosts in which you're interested, since they may not correspond to the hosts in the system's /etc/hosts file, and you probably really do want them looked up via DNS each time, rather than maintaining static addresses for them.

Read full article from Bash hostname completion | Arabesque

Better Bash history | Arabesque

By default, the Bash shell keeps the history of your most recent session in the .bash_history file, and the commands you've issued in your current session are also available with a history call. These defaults are useful for keeping track of what you've been up to in the shell on any given machine, but with disks much larger and faster than they were when Bash was designed, a little tweaking in your .bashrc file can record history more permanently, consistently, and usefully.

Append history instead of rewriting it

You should start by setting the histappend option, which will mean that when you close a session, your history will be appended to the .bash_history file rather than overwriting what's in there.

shopt -s histappend

Allow a larger history file

The default maximum number of commands saved into the .bash_history file is a rather meager 500. If you want to keep history further back than a few weeks or so, you may as well bump this up by explicitly setting $HISTSIZE to a much larger number in your .bashrc. We can do the same thing with the $HISTFILESIZE variable.

HISTFILESIZE=1000000  HISTSIZE=1000000

The man page for Bash says that HISTFILESIZE can be unset to stop truncation entirely, but unfortunately this doesn't work in .bashrc files due to the order in which variables are set; it's therefore more straightforward to simply set it to a very large number.

If you're on a machine with resource constraints, it might be a good idea to occasionally archive old .bash_history files to speed up login and reduce memory footprint.

Don't store specific lines

You can prevent commands that start with a space from going into history by setting $HISTCONTROL to ignorespace. You can also ignore duplicate commands, for example repeated du calls to watch a file grow, by adding ignoredups. There's a shorthand to set both in ignoreboth.

HISTCONTROL=ignoreboth

You might also want to remove the use of certain commands from your history, whether for privacy or readability reasons. This can be done with the $HISTIGNORE variable. It's common to use this to exclude ls calls, job control builtins like bg and fg, and calls to history itself:

Read full article from Better Bash history | Arabesque

Linux Tips: take control of your bash_history - MDLog:/sysadmin

I spend most of my time working in front of a black and white terminal of remote SSH connections to various servers. This means that I use bash (as my preferred shell) most of the day. And bash history is a very important feature of bash that saves me much time by recalling previous commands I have typed. Here are some tricks on how you can optimize with some simple configurations settings the usage your bash history.

1. Don't save duplicates: This is my favorite…

HISTCONTROL=ignoreboth

this causes any lines matching the previous history entry not to be saved. Other options for HISTCONTROL: ignorespace, lines which begin with a space character are not saved in the history list; erasedups causes all previous lines matching the current line to be removed from the history list before that line is saved.

2. Size of the history: HISTSIZE: The number of commands to remember in the command history. The default value is 500.

HISTSIZE=500

You can set this to 0 and disable the usage of the history file.

3. Others: HISTFILE: The name of the file in which command history is saved. The default value is ~/.bash_history. HISTIGNORE: A colon-separated list of patterns used to decide which command lines should be saved on the history list.

How do you set these options? Either export them in your environment in your personal bash configuration file (~/.bashrc) or in the global bash configuration file (/etc/bash.bashrc). The name of the configuration files can depend from your Linux distribution and bash version (the ones included are from Debian Linux), but you can always see your particular options using man bash. So, you can add in your configuration files the parameters you want like this:

Read full article from Linux Tips: take control of your bash_history - MDLog:/sysadmin

7 Tips - Tuning Command Line History in Bash - ShellHacks

7 Tips that can help you to improve you Bash history file.

You will learn how to add date and time to bash history file, increase history size, ignore specific commands and much more …

Every command that you enter, is stored in the file ~/.bash_history. Run history to see your last commands.

You can improve your Bash history, appending different environment variables to your ~/.bashrc file.

After modifying ~/.bashrc file, execute the following command to apply changes:

Read full article from 7 Tips - Tuning Command Line History in Bash - ShellHacks

java - How to adjust the default size of the Javadoc popup window in Eclipse? - Stack Overflow

Ive never found options for setting default sizes for Javadoc hovers. You can always use the Javadoc view though in Window > Show View > Javadoc. You can set this size and the Javadoc of the highlighted code will be shown in here.

Read full article from java - How to adjust the default size of the Javadoc popup window in Eclipse? - Stack Overflow

《线程池系列六》-Guava ListenableFutureTask - 简书

Guava中的ListenableFuture提供了添加监听的方法addListener()，该方法添加的监听会在任务执行完成之后执行（看到这就应该想起FutureTake类的done()方法）。就像事件触发回调一样，方便我们进行复杂业务时的逻辑处理。

ListenableFuture接口

该接口继承Future接口，并在Future接口上添加addListener()方法，目的就是添加任务执行完成后的处理逻辑，可以多次调用。不管Future任务为何种状态，都可以调用该方法。

Read full article from 《线程池系列六》-Guava ListenableFutureTask - 简书

Find and Replace with newline - features - Atom Discussion

If you turn on Regular Expression mode with the .* button on the right, you can type \n as the replacement string to replace the commas. You should also replace the trailing space after the comma at the same time to get exactly what you want.

Read full article from Find and Replace with newline - features - Atom Discussion

Hermetic environment for your functional tests

1. March 9, 2015 Andrii Dzynia Software Engineer in Quality @adzynia Hermetic environment for your functional tests

2. 2 Spotify brings you the right music for every moment! Over 20,000 songs added every day Started in 2006 (in Sweden) Now 1500+ employees, 600+ engineers 5(STO, GBG, NYC, BOS, SF) engineering offices Over 30 million songs available Over 60 million active users Over 15 million paying subscribers

3. 3 https://labs.spotify.com/2013/03/15/backend-infrastructure-at-spotify/ High level architectural view

Read full article from Hermetic environment for your functional tests

Best Test Structure::Hermetic Test Pattern - Tech Travel Hub

In my last post-Structure of Automation Test Cases, I have shown how we can improve the test structure and make a better one.Too many tests will make feedback loop delayed and too less tests may not have enough coverage.Sometimes too many tests are added to a single E2E(End to End) script.This kind of test design will make it spaghetti. The goal is to design a significant approach that will lower down the feedback loop.
Now lets looks at the question below:

What is the biggest benefit or goal ?
What is the cost ?
How is the team?
What training team needs?
What is holding automation back?

We have to prioritise the issues and resolve one by one. Now in this post I am trying to venture the pattern on which the structure is made. The test structure is made on Hermetic Test Pattern. As per the Hermetic test pattern each test should be completely Independent and should not depend on other test. So,It should be atomic in nature and self sufficient.As per the maintenance concern,each test case should be maintained concern,each testcase should be maintained separately and if any dependency outside of the test found(may be a 3rd party library,3rd party service) test engineer should cut the linkage with the service.

Read full article from Best Test Structure::Hermetic Test Pattern - Tech Travel Hub

Hermetic testing – Fragmented

In this mini fragment, Donn and Kaushik share some thoughts on real world testing with Android development – a favorite topic of theirs.

Kaushik recently ran into a case where an espresso test fails because the UI stops performing. It's an interesting discussion on figuring out what matters when you write your tests. They dive into strategies and techniques around testing. What makes a good test, what should you be testing?

They then talk about why Hermetic testing is pretty hard on mobile and ideas around a simple solution that could be provided out of the box. They then round it up talking about TDD and it's role in today's world.

Read full article from Hermetic testing – Fragmented

Google Guice - Optional Injection

Injection is a process of injecting dependency into an object. Optional injection means injecting the dependency if exists. Method and Field injections may be optionally dependent and should have some default value if dependency is not present. See the example below.

Read full article from Google Guice - Optional Injection

OptionalBinder (Guice 4.1 API)

An API to bind optional values, optionally with a default value. OptionalBinder fulfills two roles:

It allows a framework to define an injection point that may or may not be bound by users.
It allows a framework to supply a default value that can be changed by users.

When an OptionalBinder is added, it will always supply the bindings: Optional<T> and Optional<Provider<T>>. If setBinding() or setDefault() are called, it will also bind T.

setDefault is intended for use by frameworks that need a default value. User code can call setBinding to override the default. Warning: Even if setBinding is called, the default binding will still exist in the object graph. If it is a singleton, it will be instantiated in Stage.PRODUCTION.

If setDefault or setBinding are linked to Providers, the Provider may return null. If it does, the Optional bindings will be absent. Binding setBinding to a Provider that returns null will not cause OptionalBinder to fall back to the setDefault binding.

If neither setDefault nor setBinding are called, it will try to link to a user-supplied binding of the same type. If no binding exists, the optionals will be absent. Otherwise, if a user-supplied binding of that type exists, or if setBinding or setDefault are called, the optionals will return present if they are bound to a non-null value.

Values are resolved at injection time. If a value is bound to a provider, that provider's get method will be called each time the optional is injected (unless the binding is also scoped, or an optional of provider is injected).

Annotations are used to create different optionals of the same key/value type. Each distinct annotation gets its own independent binding.

Read full article from OptionalBinder (Guice 4.1 API)

BoundFields · google/guice Wiki

Test code which uses Guice frequently follows the pattern whereby you create several fields in your test class and bind those fields to their types using a custom Module. BoundFieldModule can help simplify this pattern by automatically binding fields annotated with @Bind.

Binding Fields Manually

Frequently in order to test classes which are injected, you need to inject mocks or dummy values for the tested class's dependencies. In order to do this, a common pattern is the following:

Read full article from BoundFields · google/guice Wiki

Google Testing Blog: Hermetic Servers

Consider a complex and rich web app. Under the hood, it is probably a maze of servers, each performing a different task and most talking to each other. Any user action navigates this server maze on its round-trip from the user to the datastores and back. A lot of Google's web apps are like this including GMail and Google+. So how do we write end-to-end tests for them?

The "End-To-End" Test

An end-to-end test in the Google testing world is a test that exercises the entire server stack from a user request to response. Here is a simplified view of the System Under Test (SUT) that an end-to-end test would assert. Note that the frontend server in the SUT connects to a third backend which this particular user request does not need.

One of the challenges to writing a fast and reliable end-to-end test for such a system is avoiding network access. Tests involving network access are slower than their counterparts that only access local resources, and accessing external servers might lead to flakiness due to lack of determinism or unavailability of the external servers.

Read full article from Google Testing Blog: Hermetic Servers

Google Testing Blog: Testing on the Toilet: Exercise Service Call Contracts in Tests

The following test mocks out a service call to CloudService. Does the test provide enough confidence that the service call is likely to work?

@Test public void uploadFileToCloudStorage() {    when(mockCloudService.write(            WriteRequest.newBuilder().setUserId("testuser").setFileType("plain/text")...))      .thenReturn(WriteResponse.newBuilder().setUploadId("uploadId").build());      CloudUploader cloudUploader = new CloudUploader(mockCloudService);        Uri uri = cloudUploader.uploadFile(new File("/path/to/foo.txt"));    // The uploaded file URI contains the user ID, file type, and upload ID. (Or does it?)    assertThat(uri).isEqualTo(new Uri("/testuser/text/uploadId.txt"));

Lots of things can go wrong, especially when service contracts get complex. For example, plain/text may not be a valid file type, and you can't verify that the URI of the uploaded file is correct.

If the code under test relies on the contract of a service, prefer exercising the service call instead of mocking it out. This gives you more confidence that you are using the service correctly:

@Test public void uploadFileToCloudStorage() {    CloudUploader cloudUploader = new CloudUploader(cloudService);    Uri uri = cloudUploader.uploadFile("/path/to/foo.txt");    assertThat(cloudService.retrieveFile(uri)).isEqualTo(readContent("/path/to/foo.txt));  }

How can you exercise the service call?

Use a fake. A fake is a fast and lightweight implementation of the service that behaves just like the real implementation. A fake is usually maintained by the service owners; don't create your own fake unless you can ensure its behavior will stay in sync with the real implementation. Learn more about fakes at testing.googleblog.com/2013/06/testing-on-toilet-fake-your-way-to.html.
Use a hermetic server. This is a real server that is brought up by the test and runs on the same machine that the test is running on. A downside of using a hermetic server is that starting it up and interacting with it can slow down tests. Learn more about hermetic servers at testing.googleblog.com/2012/10/hermetic-servers.html.

If the service you are using doesn't have a fake or hermetic server, mocks may be the only tool at your disposal. But if your tests are not exercising the service call contract, you must take extra care to ensure the service call works, such as by having a comprehensive suite of end-to-end tests or resorting to manual QA (which can be inefficient and hard to scale).

Read full article from Google Testing Blog: Testing on the Toilet: Exercise Service Call Contracts in Tests

Is gRPC the Future of Client-Server Communication? - Bleeding Edge Press - Medium

A logical place to start when answering this question is to first talk about what the letters in gRPC mean. It is an acronym after all:

Remote
Procedure
Calls

This is the programming idiom that gRPC presents to application developers.

So what is the "g" in "gRPC?" This technology was created by Google as an open source evolution of their internal RPC technology named Stubby, and they continue to be the stewards of the official open source project. So the "g" is widely thought to stand for "Google." Google has tried to make it clear, however, that they want a community collaborating with and accepting contributions and input from developers outside of Google. To that end, the "g" has never officially meant "Google."

In fact, a new meaning is assigned to the "g" for each release. In August 2016 during the 1.0 release of gRPC the acronym stood for "gRPC Remote Procedure Calls." In the numerous minor releases since then, the "g" has gone through equally numerous redefinitions, including good, green, gambit, glamorous, and glorious. This history of what the "g" stands for is documented in their main repo on Github.

Let's take a look at what gRPC is, starting with some of the principles on which gRPC is built, and also look at what distinguishes gRPC from other RPC systems, and how it compares to other widely-used technologies.

Read full article from Is gRPC the Future of Client-Server Communication? - Bleeding Edge Press - Medium

InjectingProviders · google/guice Wiki

With normal dependency injection, each type gets exactly one instance of each of its dependent types. The RealBillingService gets one CreditCardProcessor and one TransactionLog. Sometimes you want more than one instance of your dependent types. When this flexibility is necessary, Guice binds a provider. Providers produce a value when the get() method is invoked:

public interface Provider<T> {    T get();  }

The provider's type is parameterized to differentiate a Provider<TransactionLog> from a Provider<CreditCardProcessor>. Wherever you inject a value you can inject a provider for that value.

Read full article from InjectingProviders · google/guice Wiki

Directories used by the IDE to store settings, caches, plugins and logs – IDEs Support (IntelliJ Platform) | JetBrains

Product directory starting with dot can be found in your user home directory, the pattern is:

 ~/.<PRODUCT><VERSION>

~ is an alias for the home directory, for example /home/john.

Read full article from Directories used by the IDE to store settings, caches, plugins and logs – IDEs Support (IntelliJ Platform) | JetBrains

Android Basics: How to Use the Share Menu « Android :: Gadget Hacks

Android allows all apps to share data with each other. For instance, if you're viewing a picture in your favorite gallery app, you can share this image over to any email app, where you can then send it to anyone. Or if you're looking at a web page in your browser, you can share the link over to any text messaging app and send it to your friend.

Read full article from Android Basics: How to Use the Share Menu « Android :: Gadget Hacks

Google Cloud Spanner: the good, the bad and the ugly

With the current state of Cloud Spanner features, it's hard to think of it as an easy replacement for an existing OLTP solution, especially once your needs outgrow it. One would have to invest a significant amount of time to build a solution around Cloud Spanner's shortcomings.

When we started the Cloud Spanner evaluation, we expected its management features to be on par with, or at least not so far from, other Google SQL solutions. But, we were surprised by the complete lack of backups and very limited resource access control. Not to mention its lack of views, no local development environment, unsupported sequences, JDBC without DML and DDL support, and so on.

So, where does this leave someone who needs to scale-out a transactional database? There doesn't yet seem to be one solution on the market that fits all use cases. There are plenty of closed and open source solutions (a few of which are mentioned in this article), each with its strengths and weaknesses, but none of them offer SaaS with 99.999% SLA and strong consistency. If high SLA is your primary objective and you're not inclined to build your own multi-cloud solution, Cloud Spanner may be the solution you are looking for. But, you should be aware of all of its limitations.

Read full article from Google Cloud Spanner: the good, the bad and the ugly

Google Guice - Binding Annotations

As we can bind a type with its implementation. In case we want to map a type with multiple implementations, we can create custom annotation as well. See the below example to understand the concept.

Read full article from Google Guice - Binding Annotations

Google researchers present Zanzibar, a global authorization system, it scales trillions of access control lists and millions of authorization requests per second | Packt Hub

Google researchers presented a paper on Google's consistent global authorization system known as Zanzibar. The paper focuses on the design, implementation, and deployment of Zanzibar for storing and evaluating access control lists (ACL). Zanzibar offers a uniform data model and configuration language for providing a wide range of access control policies from hundreds of client services at Google. The client services include Cloud, Drive, Calendar, Maps, YouTube and Photos.

Zanizibar authorization decisions respect causal ordering of user actions and thus provide external consistency amid changes to access control lists and object contents. It scales to trillions of access control lists and millions of authorization requests per second to support services used by billions of people. It has maintained 95th-percentile latency of less than 10 milliseconds and availability of greater than 99.999% over 3 years of production use.

Read full article from Google researchers present Zanzibar, a global authorization system, it scales trillions of access control lists and millions of authorization requests per second | Packt Hub

Zanzibar: Google’s Consistent, Global Authorization System | USENIX

Zanzibar: Google's Consistent, Global Authorization System | USENIX

Determining whether online users are authorized to access digital objects is central to preserving privacy. This paper presents the design, implementation, and deployment of Zanzibar, a global system for storing and evaluating access control lists. Zanzibar provides a uniform data model and configuration language for expressing a wide range of access control policies from hundreds of client services at Google, including Calendar, Cloud, Drive, Maps, Photos, and YouTube. Its authorization decisions respect causal ordering of user actions and thus provide external consistency amid changes to access control lists and object contents. Zanzibar scales to trillions of access control lists and millions of authorization requests per second to support services used by billions of people. It has maintained 95th-percentile latency of less than 10 milliseconds and availability of greater than 99.999% over 3 years of production use.

Ruoming Pang, Google

Ramon Caceres, Google

Mike Burrows, Google

Zhifeng Chen, Google

Pratik Dave, Google

Nathan Germer, Google

Alexander Golynski, Google

Kevin Graney, Google

Nina Kang, Google

Lea Kissner, Humu, Inc.

Jeffrey L. Korn, Google

Abhishek Parmar, Carbon, Inc.

Christopher D. Richards, Google

Mengzhi Wang, Google

Read full article from Zanzibar: Google's Consistent, Global Authorization System | USENIX

Making our Android Studio Apps Reactive with UI Components & Redux

Recently Netflix has started building mobile apps to bring technology and innovation to our Studio Physical Productions, the portion of the business responsible for producing our TV shows and movies.

Our very first mobile app is called Prodicle and was built for Android & iOS using the same reactive architecture in both platforms, which allowed us to build 2 apps from scratch in 3 months with 4 software engineers.

The app helps production crews organize their shooting days through shooting milestones and keeps everyone in a production informed about what is currently happening.

Read full article from Making our Android Studio Apps Reactive with UI Components & Redux

Modernizing the Web Playback UI - Netflix TechBlog - Medium

Since 2013, the user experience of playing videos on the Netflix website has changed very little. During this period, teams at Netflix have rolled out amazing video playback features, but the visual design and user controls of the playback UI have remained the same.

Read full article from Modernizing the Web Playback UI - Netflix TechBlog - Medium

21 VSCode Shortcuts to Make Coding Faster and More Fun

So you've installed some great tools or extensions to accelerate your development flow and are having a great time. That's great but there's a chance you're missing out on some of the shortcuts that VS code offers. Not everyone has time to go through every shortcut to find the ones that help them code faster and funner — there are just too many!

In addition, a lot of the points listed in this article can be custom bound to a keyboard shortcut, so remember — you don't have to open up the command palette every time you want to invoke a command.

In this post I will list my top favorite shortcuts that make me a faster coder. I personally think it makes coding a lot more fun when applying these shortcuts. Watching my time get cut in half makes me feel proactive!

Read full article from 21 VSCode Shortcuts to Make Coding Faster and More Fun

【译】21个 VSCode 快捷键，帮助你快乐编程

我们通过安装一些工具或者扩展，有助于提升我们的编程效率，同样的掌握一些非常有用的快捷键，可以促使我们更加愉悦的开发。虽然每个人并不一定有足够的时间和经历去掌握每个快捷键的细节，但是下面 21 个快捷键一定可以帮到你。

一次性搜索全部文件

Windows: Ctrl+ Shift+ F

Mac: Control+ Shift+ F

Read full article from 【译】21个 VSCode 快捷键，帮助你快乐编程

新海诚_百度百科

新海诚在大学读书期间就加入了日本Falcom游戏会社，1995年大学毕业后加入了该公司，期间他以本名新津诚参与了包括程序、美工、动画与宣传影片制作的多种工作^[1] 。

在职Falcom期间，新海诚开始了个人动画短片创作。1997年，执导了1分30秒的黑白短片《遥远世界》，该片获得了eAT金沢'98にて特别赏^[1] 。1998年，拍摄了3D动画短片《被包围的世界》。

2000年，执导了黑白动画短片《她和她的猫》，该片以猫的视角，讲述了它与女主人淡然忧伤的故事^[6] ，获得了第12届DoGA CG动画大赛最优秀奖^[1] ；同年初夏，新海诚开始制作动画电影《星之声》，但由于工作的繁忙，导致《星之声》一度停滞不前。

2001年5月，新海诚向Falcom提交辞职，之后《星之声》的制作步上正轨，2002年1月宣告完工^[1] ；同年，新海诚参与制作了Minori游戏会社游戏《Bittersweet Fools》。

2004年11月20日，执导的科幻动画电影《云的彼端，约定的地方》，该片为其个人首部长篇电影^[7] ，获得了第59届日本每日映画大奖动画奖^[2] 。

2006年，担任Minori游戏会社游戏《EF - the first tale》的动画监制。2007年3月3日，自编自导的爱情动画电影《秒速5厘米》上映，该片获得了亚洲太平洋电影节最佳动画电影奖^[3] 。

2011年5月7日，执导的奇幻冒险动画电影《追逐繁星的孩子》上映^[8] ；2012年，新海诚入选内阁国家战略室举办的"在世界范围内活跃、宣传'日本'的日本人项目"，获颁感谢状^[4] 。

2013年5月31日，自编自导的爱情动画电影《言叶之庭》上映^[7] ，该片获得了斯图加特国际动画电影节长篇部门最优秀奖^[4] 。

2016年8月26日，自编自导的动画电影《你的名字。》上映，该片由神木隆之介、上白石萌音担任主要配音，新海诚凭借该片获得了第40届日本电影学院奖最佳编剧奖^[5] 及第26届日本电影评论家大奖最佳导演奖^[9] ；11月3日，获得了第29届东京国际电影节感谢奖^[10] 。

2018年12月，新海诚担任导演、编剧、原作的动画长片《天气之子》曝光主视觉海报，并定档2019年7月19日在日本上映^[11]

Read full article from 新海诚_百度百科

《天气之子》前期无剧透影评帖

新海诚导演的新作《天气之子》还是如期在19号全日上映。

在《你的名字》大火之后，这一部作品压力会显然大很多，毕竟你的名字之后越来越多的人开始和宫崎骏进行比较。如同《秒速五厘米》后新海诚的作品自己都会担心画质的问题，但是导演真的很厉害，无论是之后的《言叶之庭》的下雨天还是《你的名字》的陨石，都还是给了自己非常大的惊喜感觉。所以对于新作，自己还是会非常期待新的画面，当然音乐依旧是非常让人期待的，再次和 RAWINDS 的合作，以及听完部分 OST 自己也打消了疑虑。由于内地还未定档，大家可以看下海外的 tweet ，话说新电影有《你的名字》的彩蛋。由于取景大多都还是在东京，因此肯定少不了圣地巡礼，不过国内还是等电影上映吧。

Read full article from 《天气之子》前期无剧透影评帖

【译】Netflix 是如何重构新的播放器 UI

这一篇是奈飞前端工程师分享 Web团队在构建新的播放器时候遇到的困惑和解决思路，我们在设计播放器的时候，可能需要考虑到诸多方面，UI 扩展，测试，底层设计，面向多业务多团队等。希望这篇文章可以帮助到你。

从2013年开始，Netflix 的团队一直将重心放到开发视频播放的新特性，而始终未关注播放的视觉UI的改进。

Read full article from 【译】Netflix 是如何重构新的播放器 UI

面试时HR问：“你离职的原因是什么？”两种回答，结局大不相同!

面试时HR问："你离职的原因是什么？"两种回答，结局大不相同!

在面试的过程中，HR通常都会询问求职者从前单位离职的原因。

例如最近我就面试了这样的两个求职者。

求职者A，刚从工作了三年的公司离职，我问他："这家公司规模挺大啊，你为什么要跳槽呢？"A回答："我在那边工作三年，感觉有点腻，所以想换个新环境。"

求职者B，两年经验，我也问了同样的问题。B回答："其实还挺舍不得原来的公司，但因为我的岗位职责今年发生了较大调整，偏离了我的职业规划，所以才考虑跳槽。而贵公司的职位非常适合我，希望有机会能加入。"

最终，A被我直接PASS了，而B通过了这轮面试。同样一个面试问题，两种回答，结局却大不相同。

员工离职原因有哪些类型

没有无缘无故的爱，也没有无缘无故的恨。当我们选择了一家公司，肯定有认同它的理由；而当我们离开一家公司，我们也会有千千万万个放弃的理由。

即使同一个人，如果是主动离开，也可能是五种以上原因的组合。

你，究竟属于哪一种呢？

从离职动机上看，大致可以分为以下六种：

1.利益型：即对老东家并非完全不满意，而是外部"诱惑"太大，如高工资、高福利、高职位等，此类员工一般都有更高的成就欲望，频繁跳槽的概率会比较大。

2.改换环境型：此类员工换工作是因为不愿意长久地呆在一个环境中，喜欢从新的环境中寻求改变，例如我曾有个同事在公司做了十年突然辞职就属于这种情况，我问她为啥要离职，她说"就是干得太久了才要走"。

3.冲动型：现在职场上冲动裸辞的员工越来越多，他们可能因为上级一句批评的话或同事的一点"冒犯"就负气离开。这类人的性格特点往往是考虑问题不够成熟，做事容易情绪化。

4.假离职型：这种类型的员工心机较重，比如他们对薪资或职位不满意，但又觉得自己的岗位在公司很重要，短时间难以替代，于是就通过辞职来投石问路。要是领导挽留，那么正好谈谈条件再留下来，以满足个人需求。

5.外力型：有些情况下，员工是属于被动型的辞职。例如公司搬迁到异地了，自己又无法克服家庭的困难只好提出离职；又例如公司经营不善，大规模裁员，员工不得已而离职。

6.自我不满型：还有些员工往往比较自卑，在工作遇到一些挫折时，就有逃避的想法。比如我曾经咨询过一个求助者，就是两年时间换了好几份工作，只要领导一批评，她就认为自己无法胜任工作，马上就想着辞职。

Read full article from 面试时HR问："你离职的原因是什么？"两种回答，结局大不相同!

Dear Agile, I’m Tired of Pretending - Columbus’ Egg - Medium

Dear Agile, I'm Tired of Pretending - Columbus' Egg - Medium

"Agile is dead." People keep saying that. But then they say, "We're just kidding." They tell you they meant the way you do Agile is dead. And stupid. But "real" Agile isn't dead. It's just that everyone does Agile wrong. So I guess real Agile is, you know, Agile in theory. Even I have done this. And you know what? I'm sick of doing it.

I was recently mustering the same old defenses online: "But but but, the problem is Waterscrumfall, not Agile as intended in the Manifesto…blah blah blah." Then Bob Marshall gave it to me straight. He basically said, "Shut up Charles. The Agile Manifesto is a crock." He made some points I had to agree with. I thought about it. The result is this post.

Here's a quiz for you. How does the first line of the Agile Manifesto begin? No peeking. Don't know? That's fine. It doesn't matter. It says, "We are uncovering better ways of developing software…." Stop. Notice it says, "developing software." It does not say, "leaning out your org," "paying down transformation debt," "cutting it out with this command-and-control crap," "focusing on outcomes and getting better at discovery work," "fixing your medieval budgeting system," or any of the other far more value-adding things people have tried to glom onto it. But the thing is, when people say that Agile pertains to the whole org, it's revisionist history. It's dishonest.

Read full article from Dear Agile, I'm Tired of Pretending - Columbus' Egg - Medium

伪装的敏捷，我好累

"敏捷已死"，人们一直这么说，但紧接着他们又说："我们只是开个玩笑"。其实这些人真正想表达的是你实践敏捷的方式已经过时并且愚不可及，而"真正的"敏捷未死，只不过大家实践敏捷的方式是错误的。因此，我认为理论上的敏捷是"真正的"敏捷。

最近我在网上也搜集到了很多古老的辩解："但是有问题的是 Water-Scrum-Fall，而不是宣言当中的敏捷。" 紧接着 Bob Marshall 直言不讳道："这位同学请你闭嘴吧，敏捷宣言就是老调重弹。"他还说了一些我不得不同意的观点，我思考了一下，下面就是我思考的结论。

阅读参考：

Water-Scrum-fall

https://www.infoq.cn/article/delivering-software-water-scrum-fall

这里有一个对你的测验：敏捷宣言的第一句是什么？不许偷看。不记得了的话，我来告诉你："我们正在探索开发软件更好的方式……"就此打住，注意到了吗，它说的是"开发软件"，并没有说到"倾斜你的组织"、"偿还转型债务"、"用这种命令和控制废话切断它"、"专注于结果并且在发现领域的工作"、"修复你的中世纪预算系统"，或任何其它人们试图掩盖的更多有价值的东西。但问题是，当人们说敏捷属于整个组织时，它就是修正主义的历史，这是不诚实的。

在宣言开始的部分是："我们正在发现……"，它并没有说："我们已从非常……获得……"。你不觉得我们从 2001 年开始意识到，大多数大型组织仍然停留在 1987 年。与流行的看法相反，下面的照片实际上并非来自 Snowbird 签署的宣言，我们是不是可以终于停止伪装的敏捷了呢？

Read full article from 伪装的敏捷，我好累

Get some info about a file

Extract the audio part of a video

Convert an audio file to another format

What is bash completion?

How it works

Why bother

Append history instead of rewriting it

Allow a larger history file

Don't store specific lines

ListenableFuture接口

Binding Fields Manually

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