Generate SSH Public Key

SSH Connection to Github account

1. checking existing SSH keys

$ ls -al ~/.ssh

# Lists the files in your .ssh directory, if they exist

2. Add existing SSH Key to Github account

$ pbcopy < ~/.ssh/id_rsa.pub

Then add this copied key to Github account SSH Key 

3. Test SSH connection

$ ssh -T git@github.com

after a few steps and add passphrase, it will successfully with below msg - 

"Hi wzunix! You've successfully authenticated, but GitHub does not provide shell access."

If get error - git@github.com: Permission denied (publickey).

Solution: Generate a new SSH Key

4. Generate a new SSH Key and add to ssh-agent

$

5. Changing passphrase for SSH Key

$ sudo ssh-keygen -p -f ~/.ssh/id_rsa

Note: Need to use 'sudo', otherwise will get 'Saving key "/Users/wzunix/.ssh/id_rsa" failed: Permission denied'

Step 2: Add new SSH key to Github account:

- https://help.github.com/enterprise/2.11/user/articles/adding-a-new-ssh-key-to-your-github-account/

Step 2.1 on Github page, Add SSH Key

Step 1: To generate a new SSH key, copy and paste the text below, making sure to substitute in your email address. The default settings are preferred, so when you're prompted to "Enter a file in which to save the key", just press Enter to continue.

ssh-keygen -t rsa -C "your_email@example.com"
# Creates a new ssh key, using the provided email as a label
# Generating public/private rsa key pair.
# Enter file in which to save the key (/Users/you/.ssh/id_rsa): [Press enter]

Next, you'll be asked to enter a passphrase.

Strongly recommend a very good, secure passphrase. For more information, see Working with SSH key passphrases.

# Enter passphrase (empty for no passphrase): [Type a passphrase]
# Enter same passphrase again: [Type passphrase again]

Which should give you something like this:

# Your identification has been saved in /Users/you/.ssh/id_rsa.
# Your public key has been saved in /Users/you/.ssh/id_rsa.pub.
# The key fingerprint is:
# 01:0f:f4:3b:ca:85:d6:17:a1:7d:f0:68:9d:f0:a2:db your_email@example.com

Then add your new key to the ssh-agent:

# start the ssh-agent in the background
eval "$(ssh-agent -s)"
# Agent pid 59566
ssh-add ~/.ssh/id_rsa

JUnit

1. Declare this is a Test method:

@Test 
public void method()

2. This method is executed before each Test:

Note: used to prepare the test environment (i.e. Read input files..)

@Before

public void method()

3. This method is executed after each Test:

Note: To cleanup environment (i.e. Delete temporary file, data..)

@After

public void method()

4.This method is executed ONLY once before start of All tests.

Note: To perform time intensive activities (i.e. DB connections..) 

@BeforeClass

public static void method()

5. This method is executed ONLY once after all tests.

Note: i.e. To disconnect DB

@AfterClass

public static void method()

6. To ignore one test method:

Note: Do not execute this method

@Ignore

some_method()

7, Fail the test if the method takes longer than n milliseconds:

Note: Fails the test if it takes > 100 milliseconds

@Test(timeout=100)

some_method()

8. Fail the test if method NOT throwing the named exception;

Note; Test has to throw out the specified exception.

@Test(expected=Some_Exception.class)

some_method()

9. Hamcrest
assertThat( actual, is(expected value));

Hamcrest comes with a library of useful matchers. Here are some of the most important ones.

• Core
• anything - always matches, useful if you don't care what the object under test is
• describedAs - decorator to adding custom failure description
• is - decorator to improve readability - see "Sugar", below
• Logical
• allOf - matches if all matchers match, short circuits (like Java &&)
• anyOf - matches if any matchers match, short circuits (like Java ||)
• not - matches if the wrapped matcher doesn't match and vice versa
• Object
• equalTo - test object equality using Object.equals
• hasToString - test Object.toString
• instanceOf, isCompatibleType - test type
• notNullValue, nullValue - test for null
• sameInstance - test object identity
• Beans
• hasProperty - test JavaBeans properties
• Collections
• array - test an array's elements against an array of matchers
• hasEntry, hasKey, hasValue - test a map contains an entry, key or value
• hasItem, hasItems - test a collection contains elements
• hasItemInArray - test an array contains an element
• Number
• closeTo - test floating point values are close to a given value
• greaterThan, greaterThanOrEqualTo, lessThan, lessThanOrEqualTo - test ordering
• Text
• equalToIgnoringCase - test string equality ignoring case
• equalToIgnoringWhiteSpace - test string equality ignoring differences in runs of whitespace
• containsString, endsWith, startsWith - test string matching

Maven - Troubleshooting

1. Re-download MAVEN repository: 
Only download repository dependency, not test the code.

• mvn clean compile -DskipTests=true

2. Proxy - (In case proxy used in Workplace): 

   Note: Set Proxy first; then download repository

    2.1 Locate "Auto Proxy Script"

• Control Panel/ Internet Options/ Connections Tab/ LAN Settings 

    2.2 Download "Proxy Data File"

    2.3 Select a proxy setting as below:

• var some_id = "PROXY some_host.com:some_port";

    2.4 Now set proxy in settings.xml config file:
         Note: some one save it under .../.m2/ folder 

• Open settings.xml from %M2_HOME%\conf directory
• Edit settings.xml as below:

      <proxy>

              <id> some_id </id>

              <active> true </active>

              <protocol> http </protocol>

              <host> some_host </host>

              <port> some_port </port>

      </proxy>

3. Force Maven to Re-download A particular Repository

    When Maven encounters a problem and unable to download A repository --> We need to use this command to re-download that Repo after problem has been solved.

• mvn dependency:purge-local-repository

4. Force Maven to Update dependencies

    Note: Used for update the jar files

• mvn clean compile -U -DskipTests=true