CS310 Java Development Setup: on UNIX and on your home PC, Spring 2009

UNIX Java setup. Add modules java6  to your .cshrc on UNIX. Note that it is important to edit .cshrc before the line "if (! $?prompt) exit", so that the edits are in effect even for the subshells that do the exit.  Just add these new modules to the "module load standard" line, so it reads "module load standard java6". To activate your new .cshrc settings, use "source .cshrc", or log out and in again.
UNIX editor: Hopefully you know emacs or another editor on UNIX.  We will do most of our software development on PCs, and then test the systems on UNIX as well as PC.  This works well because of the robust portability of Java.  Project deliveries are on UNIX.

UNIX java setup test:   (Use "source .cshrc" first if you just changed .cshrc.)
java -version   should output
java version "1.6.0_04", plus two more lines of text.
The JAVA_HOME environment variable is needed by some ant tasks and other tools.  To check it:
env|grep JAVA    should output 
JAVA_HOME=/tools/jdk-1.6.0_04/usr/jdk/jdk1.6.0_04

env|grep CLASSPATH    should output nothing.  If it does give output, try to hunt down the source.  If it has junit.jar, that's OK.  If it does have other needed jars, it should also have "." to include the current directory, with a colon separating it from the other jar(s), for example, CLASSPATH=/tools/junit-3.8.1/junit.jar:.

Home PC/Mac Setup

Java – We will be using Java 6 from Sun.  Everything we need from Sun is in the Java SE (Java Standard Edition) download, that is, the  JDK (Java Development Kit) for Java 6.  Note that the JRE (Java runtime environment) is not enough. Download and install the latest (Update 11 as of Jan., '09)  JDK from http://java.sun.com/javase/downloads/index.jsp. It takes about 160MB of disk space. Note that the Java SE installation will install a system JRE, i.e., possibly disrupt other Java development on the system if you need an older Java (Java 1.4 say)  for some reason, but fine if this system is used only for current Java development. Java 6 can be used as a maintenance release of Java 5 for normal Java programming.

      

JAVA_HOME and Path:  Use System Control Panel>Advanced>Environment to define the JAVA_HOME user environment variable as c:\Program Files\Sun\jdk1.6.0_0x or c:\Sun\jdk1.6.0_0x or whereever you put the JDK download. To enable command-line java development,  edit your user Path environment variable to include your JDK's bin directory, using %JAVA_HOME%\bin as its value. Use a semicolon between entries in the value of Path. For example, my Path value has c:\Program Files\emacs\bin; %JAVA_HOME%\bin;    

       Windows java setup test (use a brand new command window if you just changed your environment variables)

java -version                    should output 

    java version "1.6.0_0x"   where x is some update number
    Java(TM) SE Runtime Environment (build 1.6.0_0x-xxx)
    Java HotSpot(TM) Client VM (build 1.6.0_0x-xxx, mixed mode, sharing)

javac -version                   should output
  javac 1.6.0_0x
 
set|find "JAVA"                 should output
  JAVA_HOME=c:\Sun\SDK\jdk          or whatever you specified as the JDK directory

dir %JAVA_HOME%    
should show directories bin, demo, include, jre, lib, and sample, as well as some files.
      
set|find  "CLASSPATH"    should output nothing.  If it does give output, look for an old environment variable setting and delete it. (junit.jar is OK to have in CLASSPATH, along with ";." to include the current directory as well.)

path                             outputs the operational Path value, which is the system Path value appended with the user Path value you set up in the control panel, so near the end of the displayed path, you should see c:\Program Files\Sun\jdk1.6.0_03\bin or c:\Sun\SDK\jdk\bin.

 Failure case:  All set up as above, but java -version shows java 1.5.x (or some other wrong version. Look for a java.exe in Window's system32 directory.  Just rename it to java_hold.exe.

It's best to have Java working first, then install eclipse, so that eclipse can find the new JDK on its own.  But if you install eclipse before Java, you can configure the new JDK in eclipse as shown in step 2. below.

You may use the IDE of your choice, but it's best to stick to ones known by many people locally, that is, emacs, Dr Java, or eclipse.  I use emacs on UNIX and eclipse on my PC and also on my Mac laptop. Eclipse takes a little time to learn, but it saves time in the long run by giving you easy ways to rename variables, classes, etc., find all uses of variable, method, etc., display an inheritance hierarchy, generate getters and setters, extract interfaces, do global edits, do visual compares, and so on.

Eclipse "Ganymede": Eclipse for Java IDE 
  1. Install the "Eclipse IDE for Java Developers" from www.eclipse.org. This also free. Put it in c:\eclipse-whatever.  
  2. Make sure eclipse sees your Java 6.0 JDK by visiting Window>Preferences>Java>Installed JREs, and looking for the Java 6 JDK. If it's not there, click the Add button, and fill in:
       JRE name: jdk6
       JRE home directory: c:\Program Files\Sun\jdk1.6.0_0x  or ...
    and clicking OK.  Then make sure it is checkedcd as the default JRE in the "Installed JREs" window you should return to.

Eclipse Notes tricks worth knowing:
1. To reinitialize a project, delete it, keeping files, in eclipse. Then go to the top-level project directory in the file system and remove all the dot files (.project, .classpath, and .settings, a directory). Then start up a new project, selecting the non-default location for the project.
2. Similarly, if you need to build a project from given files, delete any dot files first.
3. If a project seems to be ignoring an edit or other showing other weirdness, use Project>Clean to clean out all the derivitive files, i.e., force a full rebuild. If this doesn't work, use trick 1.

Emacs is installed on all our UNIX systems, and comes with Mac OSX.
Installing Emacs on PC: See http://cs11x.cs.umb.edu/mediawiki/index.php/Emacs
Simply use cs310 instead of cs110.

Transferring Files to our UNIX site: you need to use secure file transfer, SSH/SFTP. ssh and scp are installed on all our UNIX systems, and come with Mac OSX. For   See http://cs11x.cs.umb.edu/mediawiki/index.php/SSH_and_SFTP