Installing Java / Eclipse / Tomcat / Maven on Ubuntu 9.10

[Joe San]

Guys,

I would like to install JDK 1.6 on my Ubuntu partition. I did try googling around for ways to do that but most of them pointed out to use sudo apt-get. What I already did is that to download the jdk binaries and I have them in the /downloads directory. I would like to proceed from here. Normally in Windows I have a seperate partition in which I install all my Java related stuff. In the same way I would like to install all Java related stuff in a location which makes sense. I'm thinking of putting it under /usr/local/. Is this good enough? Linux experts, please guide me in getting this installed and the JAVA_HOME to be set. Appreciate your help!

[Joe San]

Found this article http://ubuntuforums.org/showthread.php?t=1113039

Will be trying this tonight!

[Peter Johnson]

Here is what I do:

I first download the *.bin file from the http://java.sun.com/javase/downloads/. My downloads always got to Desktop, but that doesn't matter here.

I then open a terminal and enter:

cd /usr
sudo mkdir java
cd java
chmod a+x ~/Desktop/jdk*.bin
sudo ~/Desktop/jdk*.bin
sudo ln -s current jdk-*
cd /usr/bin
sudo rm java                                       [[NOTE: there might be a few more to remove, do 'ls -al ja*' to find out]]
sudo ln -s /usr/java/default/bin/java
sudo ln -s /usr/java/default/bin/jar

(Replace the '*' in the above with the actual name)

Let me repeat the above steps in paragraph form:
Create a /usr/java directory and install the JDK into it. Then create a 'default' symbolic link to the JDK home directory. In /usr/bin, add symbolic links for java, jar and perhaps some of the other tools in java_home/bin.

Finally, in .bashrc (or similar file) set JAVA_HOME to /usr/java/current.

My placement of the JDK follows where the JDK gets installed in RHEL and Fedora. If you download the JDK RPM from Sun's web site and use that to install, that is where it places it.

By the way, since /usr/bin/java (and the other apps) and JAVA_HOME all reference /usr/java/default, when you install another version of the JDK all you have to do after running the jdk*.bin is switch /usr/java/default to it - no need to reset the app links nor change JAVA_HOME - they are already correct.

[Joe San]

Thanks Peter. I tried to follow the website link that I have posted and later found your reply. Anyways, got it successfully installed. Now next step would be to get Maven installed.

[Joe San]

I guess it would be pretty much the same like I did when I installed java. Just download Maven, unpack the contents and move it to the desired location and then set the MAVEN_HOME.

[Peter Johnson]

For Maven, Tomcat, Eclipse, etc, I place those in /opt. But first I change the ownership to my user id. And I always get them from their respective web sites, I never use the Ubuntu repository nor apt-get to install them.

[Joe San]

I some how messed that up initially but later managed to get this done somehow. Did the following to install Maven.

(1) Downloaded the maven 2.2.1 tar.gz file from apache maven website
(2) Untarred it in the same location (under /home/username/Downloads) using the command tar -zxvf apachemaven.tar.gz
(3) Moved the untarred contents to the location under /usr/local/

Now how do I set the classpath for Maven? I mean I want to set MAVEN_HOME so that I could call mvn tasks and goals from the terminal. Any ideas on how to do this?

[Joe San]

Peter Johnson wrote:For Maven, Tomcat, Eclipse, etc, I place those in /opt. But first I change the ownership to my user id. And I always get them from their respective web sites, I never use the Ubuntu repository nor apt-get to install them.

Peter is there any reason as to why you place it under /opt? I have already placed that under /usr/local/. Would this make any difference? I'm just waiting for your reply after which I would change accordingly and set my M2_HOME. Thanks for the help!

[Joe San]

Just did a bit of googling and came to know that /opt is kind of Program Files equivalent in windows. Well, then why did I install java under /usr/java? I could very well done that under /opt/java?? Am I right?

[Joe San]

Would the export option work as well to set the Maven Home?

[Peter Johnson]

Actually, /usr is the area where programs that come with the distro tend to get installed. Like I wrote earlier I use /usr/java because that is where i was used to it appearing in Fedora and RHEL when installing the JDK RPM. The /opt directory is meant for optional software packages installed by the user, so that is where I usually place all the stuff that I download and install myself.

You can leave Maven where you placed it, just set M2_HOME to /usr/local/apache-maven-2.2.1/bin

One of the reasons I put everything in /opt is that I share much of the /opt contents between Windows and Linux when i dual-boot. This way I have only one installation of Maven, for example, that is used in Linux and Windows. I do the same for M2_REPO - one repository of JARs shared by both OSes. Of course you have to be careful that the app can handle this - Eclipse can't so I end up with separate Eclipse installs for Linux and Windows.

[Joe San]

I got it. Thanks for the reply! Danke!

[Joe San]

Now I'm facing troubles with setting Maven Home. Even after setting M2_HOME, I'm not able to execute mvn --version. I have the following in my profile under /etc/

export JAVA_HOME=/usr/java/jdk1.6.0_18/bin/java
export JDK_HOME=/usr/java/jdk1.6.0_18
export M2_HOME=/opt/Softwares/apache-maven-2.2.1
export M2=/opt/Softwares/apache-maven-2.2.1/bin
export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/java/jdk1.6.0_18/bin

Is there anything that I'm missing here? Help!

[Joe San]

Got the following error when I tried it,

jothi@jothipc:~$ mvn --version
The program 'mvn' is currently not installed.  You can install it by typing:
sudo apt-get install maven2
mvn: command not found
jothi@jothipc:~$ 

[Joe San]

After adding the M2_HOME to the path, the path looks like this in profile

export JAVA_HOME=/usr/java/jdk1.6.0_18/bin/java
export JDK_HOME=/usr/java/jdk1.6.0_18
export M2_HOME=/opt/Softwares/apache-maven-2.2.1
export M2=/opt/Softwares/apache-maven-2.2.1/bin
export MAVEN_HOME=/opt/Softwares/apache-maven-2.2.1
export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/java/jdk1.6.0_18/bin
export PATH=/usr/java/jdk1.6.0_18/bin:/opt/Softwares/apache-maven-2.2.1/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games

And now getting the following message when giving mvn --version

jothii@jothipc:~$ mvn --version
Error: JAVA_HOME is not defined correctly.
  We cannot execute /usr/java/jdk1.6.0_18/bin/java/bin/java
jothii@jothipc:~$ 

[Joe San]

So finally got rid of this problem. Modified the JAVA_HOME accordingly.

[Peter Johnson]

It would be better is you set your path like this:

export PATH=$JAVA_HOME/bin:$M2_HOME/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games

Then, when you update the JDK you only have to change JAVA_HOME because the PATH will pick up the new setting. Ditto for updating Maven.

[Joe San]

Thanks once again for the mention.

[Joe San]

Peter, just another question to you. You just mentioned in your post above that you have just one local maven repository shared between your windows system and the linux system. Can you please let me know on how I could acheive that? I have a windows partition (around 20 GB) and I have just kept that as my local maven repository and I have in the past already created projects using that as the local repository which means that I have most of my jars there. Now how can I expose this to the linux partition? I mean I want to specify this windows partition with a folder called MavenRepository to be specified as the local repository for all my builds from the linux partition? How can I do this?

[Peter Johnson]

Executive summary: I mount the Windows partitions and make a symbolic link to reference the repository there.

Details:
While installing Ubuntu, on the disk partition, I alway choose manual partitioning. Then, besides creating the swap partition and the root partition, I also edit the Windows partition indicating that it is NTFS and that I want it mounted at /mnt/win7 (in the case of my laptop). The installation script then sets up /etc/fstab for me. Of course, I could always mount it later by adding it to my /etc/fstab file and creating the /mnt/win7 directory. Here is the line in fstab:

UUID=0C8C06EA8C06CDE0 /mnt/win7       ntfs    defaults,nls=utf8,umask=007,gid=46 0       1

or this would work as well

/dev/sda2         /mnt/win7       ntfs    defaults        0       0

Once the mount is established, it is simple to use 'ln -s' to create a repository directory in the location expected. For example:

ln -s /mnt/win7/User/peter/.m2/repository ~/.m2/repository

However, I dislike having the repository showing up under my account. So I always edit the ~/.m2/settings.xml file to specify a different location, usually at /opt/m2_repo. (In Windows, this is c:\opt\m2_repo on my laptop byt d:\opt\m2_repo on my desktop.) Then the 'ln -s' becomes:

ln -s /mnt/win7/opt/m2_repo /opt/m2_repo

Though lately I have been thinking of moving m2_repo out of /opt, perhaps locating it at /data/m2_repo. I tend to backup /opt and having to ignore /opt/m2_repo (which I never back up , it is easy to recreate) gets to be a hassle.

[Joe San]

Thanks for the details. But since I'm running Ubuntu on my VirtualBox, is is just by editing the /mnt/fstab that I could acheive this? Anyways, I would try this today after work.

[Peter Johnson]

I usually don't share files/directories between a Linux VM and its Windows host. But googling for linux mount windows share should yield some helpful advice.