JPA @ManyToMany sample

This is a JPA @ManyToMany sample.

@Entity
public class Link {
...

@ManyToMany
@JoinTable(
name = "link_tag",
joinColumns = @JoinColumn(name = "link_id"),
inverseJoinColumns = @JoinColumn(name = "tag_id"))
private List<Tag> tags;

...
}

@Entity
public class Tag {
...

@ManyToMany
@JoinTable(
name = "link_tag",
joinColumns = @JoinColumn(name = "tag_id"),
inverseJoinColumns = @JoinColumn(name = "link_id"))
private List<Link> links;

...
}

Reference:
http://www.java2s.com/Code/Java/JPA/ManyToManyJoinedTable.htm

Exclude @ToString in @Data in Lombok

I guess there is no way to exclude @ToString in @Data in Lombok.

@Data is equivalent to

@Getter
@Setter
@RequiredArgsConstructor
@ToString
@EqualsAndHashCode

So instead of @Data, you can just use the following annotations:

@Getter
@Setter
@RequiredArgsConstructor
@EqualsAndHashCode

JsRender remote template sample

This is a JsRender remote template sample.

https://github.com/izeye/samples-javascript/tree/master/samples/jsrender/remote_template

Reference:
http://www.jsviews.com/#samples/jsr/composition/remote-tmpl

JavaScript multiline string

To use multiline string in JavaScript,

you can use '\' as follows:

$.templates("personTemplate",
    ' \
    <tr> \
        <td>{{>name}}</td> \
        <td>{{>age}}</td> \
    </tr> \
    '
);

Reference:
http://stackoverflow.com/questions/805107/creating-multiline-strings-in-javascript

Create a self-signed test certificate in Linux

To create a self-signed test certificate in Linux,

you can use the following command:

openssl req -new -x509 -key server.key -out server.crt

You can find the meaning of options in man page.

From 'man openssl':

openssl - OpenSSL command line tool

req       X.509 Certificate Signing Request (CSR) Management.

From 'man req':

       -new
           this option generates a new certificate request. It will prompt the
           user for the relevant field values. The actual fields prompted for
           and their maximum and minimum sizes are specified in the
           configuration file and any requested extensions.

           If the -key option is not used it will generate a new RSA private
           key using information specified in the configuration file.

       -x509
           this option outputs a self signed certificate instead of a
           certificate request. This is typically used to generate a test
           certificate or a self signed root CA. The extensions added to the
           certificate (if any) are specified in the configuration file.
           Unless specified using the set_serial option 0 will be used for the
           serial number.

       -key filename
           This specifies the file to read the private key from. It also
           accepts PKCS#8 format private keys for PEM format files.

       -out filename
           This specifies the output filename to write to or standard output
           by default.

To create a self-signed test certificate with a CSR in Linux,

you can use the following command:

openssl req -in ../csr/cert.csr -x509 -key ../private_key/rsa/privkey.pem -out cacert.pem -days 1095

You can find the meaning of options in man page.

From 'man req':

       -in filename
           This specifies the input filename to read a request from or
           standard input if this option is not specified. A request is only
           read if the creation options (-new and -newkey) are not specified.

       -days n
           when the -x509 option is being used this specifies the number of
           days to certify the certificate for. The default is 30 days.

Reference:
https://www.openssl.org/docs/HOWTO/certificates.txt

Create a CSR (Certificate Signing Request) in Linux

To create a CSR in Linux,

you can use the following command:

openssl req -newkey rsa:2048 -nodes -keyout server.key -out server.csr

You can find the meaning of options in man page.

From 'man openssl':

openssl - OpenSSL command line tool

req       X.509 Certificate Signing Request (CSR) Management.

From 'man req':

req - PKCS#10 certificate request and certificate generating utility.

       -newkey arg
           this option creates a new certificate request and a new private
           key. The argument takes one of two forms. rsa:nbits, where nbits is
           the number of bits, generates an RSA key nbits in size.
           dsa:filename generates a DSA key using the parameters in the file
           filename.

       -nodes
           if this option is specified then if a private key is created it
           will not be encrypted.

       -keyout filename
           this gives the filename to write the newly created private key to.
           If this option is not specified then the filename present in the
           configuration file is used.

       -out filename
           This specifies the output filename to write to or standard output
           by default.

To create a CSR with a private key in Linux,

you can use the following command:

openssl req -new -key ../private_key/rsa/privkey.pem -out cert.csr

You can find the meaning of options in man page.

From 'man req':

       -new
           this option generates a new certificate request. It will prompt the
           user for the relevant field values. The actual fields prompted for
           and their maximum and minimum sizes are specified in the
           configuration file and any requested extensions.

           If the -key option is not used it will generate a new RSA private
           key using information specified in the configuration file.

       -key filename
           This specifies the file to read the private key from. It also
           accepts PKCS#8 format private keys for PEM format files.

References:
http://en.wikipedia.org/wiki/Certificate_signing_request
https://www.digicert.com/csr-creation-apache.htm
https://www.openssl.org/docs/HOWTO/certificates.txt

Jenkins build triggered by Git push

To build by Git push in Jenkins,

you can set a project configuration as follows:

Configure -> Build Triggers -> Poll SCM -> Schedule -> H/5 * * * *

Now Jenkins will poll the repository for checking any change every 5 minutes.

You can check the polling log at 'Git Polling Log' menu.

As you can see, it's not really event-based but polling-based.

I haven't tried event-based approach yet.

Campfire for group chat

For group chat, you can use Campfire.

It's web-based and provides iOS app.

It's basically paid service but free for groups which have less than 5 people.

Unfortunately, I prefer application rather than web and use Android.

References:
https://campfirenow.com/
https://campfirenow.com/signup

How to use a snapshot version of Spring Boot

To use a snapshot version of Spring Boot,

modify build.gradle as follows:

buildscript {
    repositories {
        maven { url "http://repo.spring.io/snapshot" }
        maven { url "http://repo.spring.io/libs-milestone" }
        maven { url "http://repo.spring.io/libs-release" }
        mavenCentral()
        mavenLocal()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:1.2.1.BUILD-SNAPSHOT")
    }
}

repositories {
    maven { url "http://repo.spring.io/snapshot" }
    maven { url "http://repo.spring.io/libs-milestone" }
    maven { url "http://repo.spring.io/libs-release" }
    mavenCentral()
    mavenLocal()
}

Reference:
http://docs.spring.io/spring-boot/docs/current-SNAPSHOT/reference/htmlsingle/

IRC client for Mac

In Mac, you can use Colloquy as an IRC client.

Reference:
http://colloquy.info/

Web-based IRC client

You can use web-based IRC client, KiwiIRC at:

https://kiwiirc.com/client

Reference:
https://kiwiirc.com/

How to use MariaDB in Spring Boot

To use MariaDB in Spring Boot,

you can set the following datasource properties in application.properties:

spring.datasource.url=jdbc:mariadb://localhost:3306/db_wic
spring.datasource.username=wic
spring.datasource.password=1234
spring.datasource.driverclassName=org.mariadb.jdbc.Driver

and add the following JDBC dependency in build.gradle:

compile("org.mariadb.jdbc:mariadb-java-client:1.1.7")

Reference:
https://mariadb.com/kb/en/mariadb/client-libraries/mariadb-java-client/about-the-mariadb-java-client/

How to execute initialization SQLs in Spring Boot

To execute initialization SQLs,

put the SQLs in 'data.sql' located in the root of the classpath.

You can turn off the feature with the following property in application.properties:

spring.datasource.initialize=false

Reference:
http://docs.spring.io/spring-boot/docs/current/reference/html/howto-database-initialization.html

Error: Cannot write to /usr/local/Cellar

You can see the following error with a brew command like 'brew install mariadb':

Error: Cannot write to /usr/local/Cellar

To fix, change the owner of the directory:

sudo chown $USER /usr/local/Cellar/

Reference:
http://stackoverflow.com/questions/4804169/installing-in-homebrew-errors

How to install MariaDB in Mac

To install MariaDB in Mac,

you can do the following command:

brew install mariadb

You can create default databases with the following command:

sudo mysql_install_db --user=mysql --datadir=/Users/izeye/mysql/data

You should replace '/Users/izeye/mysql/data' with your 'datadir'.

You can run MariaDB server with the following commands:

cd '/usr/local/Cellar/mariadb/10.0.15'

sudo /usr/local/Cellar/mariadb/10.0.15/bin/mysqld_safe --datadir='/Users/izeye/mysql/data'

You can also use mysql.server script.

Open the script with the following command:

vi /usr/local/bin/mysql.server

Set your 'datadir':

datadir=/Users/izeye/mysql/data

Start the script:

sudo mysql.server start

Be careful with your previous MySQL data.

You'd better backup your MySQL data before trying to install MariaDB.

References:
https://mariadb.com/kb/en/mariadb/documentation/getting-started/compiling-mariadb-from-source/building-mariadb-on-mac-os-x-using-homebrew/
http://dev.mysql.com/doc/refman/5.0/en/mysql-install-db.html

How to give sudo permission to a user in Mac

To give sudo permission to a user in Mac,

you can do the following command:

sudo visudo

and add the following line:

wic     ALL=(ALL) ALL

'wic' should be replaced with your username.

Reference:
http://mithunme.wordpress.com/2013/02/10/adding-a-standard-user-to-etcsudoers-in-mac-os-x/

Change Spring Data REST API URI in Spring Boot

To change Spring Data REST API URI in Spring Boot,

you can add the following property in application.properties:

spring.data.rest.base-uri=/api

Reference:
http://stackoverflow.com/questions/23377036/spring-boot-starter-data-rest-change-url-of-repository-from-the-root-uri

How to remove NO_EXTERNAL_MSGS in IRC channel

You can check IRC channel modes by the following command:

/mode #wic-site

You can remove NO_EXTERNAL_MSGS by the following command:

/mode #wic-site -n

References:
http://www.irchelp.org/irchelp/irctutorial.html
https://www.alien.net.au/irc/chanmodes.html

Where is Git configuration file?

Git configuration file is:

~/.gitconfig

Reference:
http://git-scm.com/book/en/v2/Getting-Started-First-Time-Git-Setup

How to show Git configuration

To show Git configuration, you can use the following command:

git config --list

Reference:
http://git-scm.com/book/en/v2/Getting-Started-First-Time-Git-Setup