How do I run FTP server in Mac OS X?

By Wayan in OS X, Tools 1 Comment

I need to test FTP client codes, so I need to find an FTP server for testing my codes. After searching for a while I find out that OS X already equipped FTP server. I am currently using OS X El Capitan 10.11.*.

Let’s now test the FTP server on Mac OS X with the following steps:

  • Launch the Terminal.app
  • Type the following command to start the FTP server.
sudo -s launchctl load -w /System/Library/LaunchDaemons/ftp.plist
  • Connect to the FTP server by running ftp localhost command.
  • We’ll be asked to enter the username and password.
$ ftp localhost
Trying ::1...
Connected to localhost.
220 ::1 FTP server (tnftpd 20100324+GSSAPI) ready.
Name (localhost:wsaryada): wsaryada
331 User wsaryada accepted, provide password.
Password: 
230 User wsaryada logged in.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp>
  • If we see the messages above and the ftp> prompt means that the FTP server works and ready to accept our command.
  • We can also try to access the FTP server using a browser. In the URL box type `ftp://localhost` to connect. We need to supply username and password to login.
  • To exit or close the connection to FTP server we can run the exit command.
  • Finally, to shut down the FTP server we run:
sudo -s launchctl unload -w /System/Library/LaunchDaemons/ftp.plist

After the FTP server ready, I can now continue to create some test program to access the FTP server. There are already some examples you can find in the Apache Commons Net category that use the FTPClient library to access FTP server.

How to use Google Maven Central mirror?

By Wayan in Maven, Tools 1 Comment

The following configuration will use Google’s mirror of the Maven Central repository. Alter your ${M2_HOME}/conf/settings.xml or ${user.home}/.m2/settings.xml to add the mirror as seen in the following configuration file.

<?xml version="1.0" encoding="UTF-8"?>
<settings>
    .
    .
    <mirrors>
        <mirror>
            <id>google-maven-central</id>
            <name>Google Maven Central</name>
            <url>https://maven-central.storage.googleapis.com</url>
            <mirrorOf>central</mirrorOf>
        </mirror>
    </mirrors>
    .
    .
</settings>

How to configure a proxy in Maven settings?

By Wayan in Maven, Tools 2 Comments

When we work behind a proxy server, we need to configure Maven to be able to connect to the internet. To enable proxy we can configure Maven settings.xml file, either in ${M2_HOME}/conf/settings.xml or ${user.home}/.m2/settings.xml file.

<?xml version="1.0" encoding="UTF-8"?>
<settings>
    .
    .
    <proxies>
        <proxy>
            <id>my-proxy</id>
            <active>true</active>
            <protocol>http</protocol>
            <host>proxy.example.org</host>
            <port>8080</port>
            <username>username</username>
            <password>password</password>
            <nonProxyHosts>*.example.org|*.example.com</nonProxyHosts>
        </proxy>
    </proxies>
    .
    .
</settings>

The <proxy> element in the configuration above contains the information about the proxy server. These include information about the host, port, username and password. Set these elements to match your proxy server configuration.

How do I specify the Java compiler version in a pom.xml file?

By Wayan in Maven, Tools 0 Comment

When you need to compile a project for a specific Java version you can configure maven compiler plugin to set the source and the target version. The following pom.xml file configuration show you how to do it.

<project>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.2</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

Invalid value for the source and the target version in our project will make our project compilation process failed. For example when we try to use the diamond operator (<>) which available in Java 7, while the maven compiler plugin is set to version 1.5, can produce compiler error like this:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project servlet-example: Compilation failure
[ERROR] /Users/wsaryada/Studio/kodejava.org/webapp-example/servlet-example/src/main/java/org/kodejava/example/servlet/SessionCounter.java:[10,51] diamond operator is not supported in -source 1.5
[ERROR] (use -source 7 or higher to enable diamond operator)

How do I install Gradle in Mac OS X?

By Wayan in Gradle, Tools 17 Comments
Gradle

In this post we will learn how to install Gradle in OS X. The following steps will guide our installation process to make Gradle available in our OS X machine. But before we start let’s take a look at the definition from wikipedia about Gradle.

Gradle is an open source build automation system that builds upon the concepts of Apache Ant and Apache Maven and introduces a Groovy-based domain-specific language (DSL) instead of the XML form used by Apache Maven of declaring the project configuration.

From: Wikipedia

I. Using Homebrew

The short and simple answer is to use the Homebrew package manager for macOS. You can visit the website for detail on how to install the Homebrew. But to help you, I’ve copied the online script to install it below:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

After installing Homebrew, just type the following command to install Gradle.

brew install gradle

Now, if you want to do it manually, here are the steps 😉

II. Manual Installation Steps

1. Download Gradle

To download visit Gradle Releases Page. Download the complete distribution which includes binaries, sources and offline documentation. For example, you can download the latest release of Gradle, as of this update the version is gradle-4.0.2-all.zip.

2. Unpacking Gradle and Configure Environment Variables

  • Open Terminal.app.
  • Create a new directory sudo mkdir /usr/local/gradle.
  • Extract the downloaded Gradle distribution archive by executing sudo unzip gradle-4.0.2-all.zip -d /usr/local/gradle.
  • Edit .bash_profile in your home directory to add GRADLE_HOME variable with the following line export GRADLE_HOME=/usr/local/gradle/gradle-4.0.2
  • Also update the PATH variable to include $GRADLE_HOME/bin. If you don’t already have the PATH variable add the following line export PATH=$GRADLE_HOME/bin:$PATH
  • Run source ~/.bash_profile to executes the update version of .bash_profile. Or you can open a new Terminal.app to make this changes active.

3. Running the Installation

To test Gradle installation open the Terminal.app and execute gradle -v command. If your installation was correct you will see something like the following output:

$ gradle -v

------------------------------------------------------------
Gradle 4.0.2
------------------------------------------------------------

Build time:   2017-07-26 15:04:56 UTC
Revision:     108c593aa7b43852f39045337ee84ee1d87c87fd

Groovy:       2.4.11
Ant:          Apache Ant(TM) version 1.9.6 compiled on June 29 2015
JVM:          1.8.0_121 (Oracle Corporation 25.121-b13)
OS:           Mac OS X 10.12.6 x86_64