Training: Day Two - Eclipse, Git, Maven

ECLIPSE

CODE STYLE

Golden RuleALWAYS USE THE GOD DAMN STYLE

✓ Minimize the change set on commits and conflicts

✓ Ease the overall readability of the code base

✓ Format the code automatically via IDE save actions

Benefits

When working on a large team, code style is no place to be creative.

SAVE ACTIONS

Save actions allow you to automate a set of tasks that will

Golden RuleALWAYS ENABLE THE GOD DAMN SAVE ACTIONS

✓ Code style is applied automatically

✓ Imports are organized according to the same set of rules

✓ Minimize the change set on commits and conflicts

Benefits

BUILD AUTOMATICALLY

When handling big projects, the build automatically feature can be an unpleasant experience.

Golden RuleSAY NO TO BUILD AUTOMATICALLY

✓ Eclipse will be more responsive

✓ Embedded servlet containers will not react to code changes

✓ Embrace the limitations of FenixFramework

Benefits

ECLIPSE JEDI

If you want to maximize your productivity, you should use less mouse and more keyboard.

Golden RuleLEARN YOUR TOOL AND SOME DAMN SHORTCUTS

✓ Increase your productivity

✓ Fix and solve your problems quicker

✓ Look smart and geek

Benefits

ECLIPSE JEDI - SHORTCUTS

Some of the most commonly used shortcuts

Auto-completeCtrl+Space

Fix FormattingCtrl+Shift+F

Open ResourceCtrl+Shift+R

Open TypeCtrl+Shift+T

Ctrl+O Quick Outline

Ctrl+L Go to Line

Ctrl+T Quick Hierarchy

GIT

WHAT IS GIT?

Distributed Version Control System (DVCS) that provides local branching for free.

Golden RuleSNAPSHOTS NOT DIFFERENCES

✓ Each clone is a safety copy

✓ Local branching is free of headaches

✓ Lots of awesome features (stash, rebase, squash, etc...)

Benefits

SVN VS GIT

Version 1 Version 2 Version 3 Version 4 Version 5

file A

file B

file C

Δ1 Δ2

Δ1 Δ2

Δ1 Δ2

Δ3

Checkins over time

Version 1 Version 2 Version 3 Version 4 Version 5

A

B

C

Checkins over time

A1

B

C1

A1

B

C2

A2

B1

C2

A2

B2

C3

SVN

GIT

GIT REPOSITORY

A GIT repository, among other artifacts, is essentially composed by:

✓ A set of commits

✓ A set of references (pointers) to commits (aka heads)

efc3a a4b4a d56d4

44d5c

head A

head B

COMMIT

✓ A set of files (blobs) that reflect the state of the project at

a particular time

✓ Reference to the parent commits (i.e. the set of states

from which the new state was originated from)

✓ A SHA1 name which grants the commit unicity and

checksum properties

A commit comprehends:

efc3a a4b4a

HEAD

✓ A reference to a particular commit with a more human

perceptive name

✓ A Git repository can have any number of heads

✓ At a given time, one of the heads is selected as the current

head, which is also a reference called HEAD

efc3a a4b4a d56d4

44d5c

head A

head B HEAD

INITIALIZING THE REPOSITORY

Git repositories work using your filesystem

The repository is handled in the .git folder in the root of your project

$ git init

STAGE ONE OR MORE FILES

$ touch README.md$ git add README.md

working

directory

staging

area

git

repository

git commit

git checkout

git add

git reset HEAD

efc3amaster

HEAD

$ git commit -m “Added README”

SAVING THE SNAPSHOT (COMMIT)

efc3amaster

HEAD

$ git add *.java

ADDING MORE FILES TO THE PICTURE

$ git commit -m “Added Java files”

efc3a

ac2admaster

HEAD

MAKING ANOTHER COMMIT

$ git branch feature/x

efc3a

ac2admaster feature/x

HEAD

BRANCHING (1)

BRANCHING (2)

$ git checkout feature/x

efc3a

ac2admaster feature/x

HEAD

QUICK BRANCHING (1)

efc3a

ac2admaster

HEAD

QUICK BRANCHING (2)

efc3a

ac2admaster feature/x

HEAD

$ git checkout -b feature/x

MERGING (1)

$ git commit -m “Fixed stuff”

efc3a

ac2ad

4ecd4

master

feature/x

HEAD

MERGING (1)

$ git checkout master

efc3a

ac2ad

4ecd4

master

feature/x

HEAD

MERGING (2)

$ git merge feature/x

efc3a

ac2ad

4ecd4

master

feature/x

HEAD

MERGING (3)

efc3a

ac2ad

4ecd4master feature/x

HEAD

Fast-Forward

MERGING (4)

efc3a

ac2ad

4ecd4masterfeature/x

HEAD

f3d3e

Other situation

MERGING (5)

$ git checkout master

efc3a

ac2ad

4ecd4masterfeature/x

HEAD

f3d3e

MERGING (6)

$ git merge feature/x

efc3a

ac2ad

4ecd4

master

feature/x

HEAD

f3d3e

4ecd4

Ugly History

DELETING A BRANCH

$ git branch -d feature/xUgly History

efc3a

ac2ad

4ecd4

master

HEAD

f3d3e

4ecd4

REBASE (1)

efc3a

ac2ad

4ecd4masterfeature/x

HEAD

f3d3e

REBASE (2)

$ git rebase -i master

efc3a

ac2ad

4ecd4master

feature/x

HEAD

2fd3e

f3d3e

MERGING (1)

$ git checkout master

efc3a

ac2ad

4ecd4master

feature/x2fd3eHEAD

Clean History

MERGING (2)

$ git merge feature/x

efc3a

ac2ad

4ecd4

master feature/x2fd3e

HEAD

Fast-Forward

GITHUB

A service that hosts Git repositories online with extra features

✓ Create forks from other repositories

✓ Push commits to your own fork

✓ Request pulls from your fork (e.g. pull-requests)

Contribution Methodology

CLONE

$ git clone --origin fork git@gihub.com:davidmartinho/fenix

The clone command creates a full copy of the repository, i.e. all commits, tags and heads.

$ git remote add origin https://github.com/FenixEdu/fenix.git

Clone your fork

Add FenixEdu as a remote to fetch updates

(the --origin fork is to name the remote fork instead of the default origin)

Pull from FenixEdu with rebase to keep history clean

$ git pull --rebase origin master

PULL REQUESTS

The pull request is not a git feature.

Github has this pull request feature to improve contributions and allows developers to merge outside contributions directly on github.

Golden RuleALWAYS MAKE PULL REQUEST ON FENIX

MAVEN

WHAT IS MAVEN?

Golden RuleDEPENDENCIES BINARIES HAVE NO PLACE IN VCS

✓ Convention over Configuration

✓ Keeps the VCS repository out of binaries

✓ Format the code automatically via IDE save actions

Benefits

Maven is much more than a project building tool. It allows you to build and manage your project.

MAVEN BUILDING BLOCKS

LIFECYCLESMaven knowns how a project is cleaned and built.A lifecycle is essentially a pre-defined list of phases to ensure such clean and build processes.

PLUGINSThe phases by themselves are worthless.We associate plugin goals (implemented by Mojos) to one of the phases.

CLEAN LIFECYCLE

pre-cleanexecute necessary tasks prior to project clean

cleandeletes all files generated during the building process

post-cleanexecutes necessary tasks needed after the building process

pre-clean

clean

post-clean

DEFAULT LIFECYCLE

generate-sources

compile

process-classes

prepare-package

package

install

deploy

24 phasesomitted the most uncommon

generate-sources

compile

process-classes

prepare-package

package

install

deploy

ffmavenplugin

HOW DOES IT WORK?

generate-sources

compile

process-classes

prepare-package

package

install

deploy

maven-compiler-pluginffmavenplugin

HOW DOES IT WORK?

generate-sources

compile

process-classes

prepare-package

package

install

deploy

maven-compiler-pluginffmavenplugin

HOW DOES IT WORK?

generate-sources

compile

process-classes

prepare-package

package

install

deploy

maven-compiler-pluginffmavenplugin

maven-jar-plugin

POM (Project Object Model)

✓ Declarative XML file

✓ Identifies your project (groupId, artifactId, version, packaging)

✓ Declares the project dependencies and their scopes

✓ Declares which plugin goals should run on which phase

✓ Declare additional repositories for the dependencies

REPOSITORIES

MAVEN CENTRAL REPOSITORYContains most of the commonly known Java libraries (e.g. log4j, hibernate, jodatime, etc...)

DSI NEXUS REPOSITORYContains our binaries (e.g. fenix-framework, tools, bennu, workflow, organization, etc...)

PROXIED THIRD-PARTY REPOSITORIESNexus allows us to proxy and cache some other third-party repositories. Good when they’re out-of-service

INSTALL VS DEPLOY

$ mvn clean install

📁 ~/.m2/repository

$ mvn clean deploy

☁fenix-ashes.ist.utl.pt/nexus