July 2011CMSC 341 CVS/Ant 1 CMSC 341 Java Packages Ant CVS Project Submission

July 2011 CMSC 341 CVS/Ant 2 Packages Java packages create libraries – A group of classes organized together into a single namespace. – Allows multiple classes with the same name MyPackage.Stack YourPackage.Stack

July 2011 CMSC 341 CVS/Ant 3 Packages A file may belong to only one package. Packages serve as a namespace in Java and create a directory hierarchy when compiled. Classes are placed in a package using the following syntax in the first line that is not a comment. package packagename; package packagename.subpackagename;

July 2011 CMSC 341 CVS/Ant 4 Multiple Stack Classes // My stack.java file package MyPackage; public class Stack { // … }; // Your stack.java file package YourPackage; public class Stack { // … };

July 2011 CMSC 341 CVS/Ant 5 Packages (cont.) The fully qualified name of a class is the packageName.ClassName. java.lang.String MyPackage.Stack YourPackage.Stack To alleviate the burden of using the fully qualified name of a class, use an import statement before the class declaration. import java.util.StringBuffer; import java.util.*; import MyPackage.Stack; import YourPackage.*;

July 2011 CMSC 341 CVS/Ant 6 Packages (cont.) It is common practice to duplicate the package directory hierarchy in a directory named src and to compile to a directory named bin. Create this directory manually in your GL account – Eclipse creates this directory structure for you Project1 proj1 src bin Example.java Example.class Package name Root of project directory tree Package name

July 2011 CMSC 341 CVS/Ant 7 Compiling with packages When using the Unix command line, classes in a package are compiled using the –d option. Given the directory structure on the previous slide, run the command below from the src directory to compile the code from the Project1/src directory to the Project1/bin directory. The -d switch tells the compiler where to place the.class file The bin directory must exist before compiling. The compiler will create the proj1 directory under bin. javac –d../bin proj1/Example.java

July 2011 CMSC 341 CVS/Ant 8 Packages and Eclipse By default Eclipse automatically creates a src/ directory when you create a new Java Project Eclipse will then automatically create a bin/ directory and associated package directory hierarchy when it compiles your Java classes – Note: the bin/ directory tree is hidden by Eclipse when in the Java perspective, but you can see it if viewing the file system.

July 2011 CMSC 341 CVS/Ant 9 What is Ant? Ant is a Java based tool for automating the build process Platform independent commands (works on Windows, Mac & Unix) XML based format Easily extendable using Java classes Ant is an open source (free) Apache project Ant files used in this course require the package directory structure described earlier Ant files used in this course require the package directory structure described earlier

July 2011 CMSC 341 CVS/Ant 10 Anatomy of a Build File Ant’s build files are written in XML  Convention is to call file build.xml Each build file contains  A project  At least 1 target Targets are composed of some number of tasks Build files may also contain properties  Like macros in a make file Comments are within blocks

July 2011 CMSC 341 CVS/Ant 11 Projects The project tag is used to define the project to which the ANT file appliesproject tag Projects tags typically contain 3 attributes  name – a logical name for the project  default – the default target to execute  basedir – the base directory relative to which all operations are performed Additionally, a description for the project can be specified from within the project tag

July 2011 CMSC 341 CVS/Ant 12 Project tag A sample build file for this project Recall that “.” (dot) refers to the current directory

July 2011 CMSC 341 CVS/Ant 13 Properties Build files may contain constants (known as properties) to assign a value to a variable which can then be used throughout the project  Makes maintaining large build files more manageable and easily changeable Projects can have a set of properties Property tags consist of a name/value pairProperty tags  Use the property names throughout the build file  The value is substituted for the name when the build file is “executed”

July 2011 CMSC 341 CVS/Ant 14 Build File with Properties A sample build file for this project

July 2011 CMSC 341 CVS/Ant 15 Tasks A task represents an action that needs execution Tasks have a variable number of attributes which are task dependant There are a number of built-in tasks, most of which are things which you would typically do as part of a build process  mkdir - create a directory  javac - compile java source code  java - execute a Java.class file  javadoc - run the javadoc tool over some files  And many, many others… For a full list see:

July 2011 CMSC 341 CVS/Ant 16 Targets The target tag has the following required attributetarget tag  name – the logical name for a target Targets may also have optional attributes such as  depends – a list of other target names for which this task is dependant upon, the specified task(s) get executed first  description – a description of what a target does Targets in Ant can depend on some number of other targets  For example, we might have a target to create a jarfile, which first depends upon another target to compile the code  Targets contain a list of tasks to be executed

July 2011 CMSC 341 CVS/Ant 17 Build File with Targets

July 2011 CMSC 341 CVS/Ant 18 Initialization Target & Tasks Our initialization target creates the build and documentation directories  The mkdir task creates a directorymkdir......

July 2011 CMSC 341 CVS/Ant 19 Compilation Target & Tasks Our compilation target will compile all java files in the source directory  The javac task compiles sources into classesjavac  Note the dependence on the init task......

July 2011 CMSC 341 CVS/Ant 20 Run Target & Tasks Our run target will execute main in the fully specified class  Typically dependent on the compile task......

July 2011 CMSC 341 CVS/Ant 21 Running Ant – Command Line Move into the directory which contains the build.xml file Type ant followed by the name of a target unix> ant run unix> ant compile Type ant at the unix prompt to run the project’s default target -- see screen shot on next page unix> ant

July 2011 CMSC 341 CVS/Ant 22 Ant screen snapshot

July 2011 CMSC 341 CVS/Ant 23 Project Submission Projects in this course will be submitted electronically through the use of an industry standard version control system named CVS. CVS can be used from the Unix command line, or from an Eclipse perspective. In either case, we must be familiar with Java packages and their associated directory structure as discussed earlier.

July 2011 CMSC 341 CVS/Ant 24 What is CVS? Concurrent Versioning System (CVS) is one of the earlier SCM systems which gained wide adoption  Open source  Easy to install and use  Simple command line client  Wide integration in a lot of development tools  Used for submitting projects in this course For good introduction on version control and CVS see the following book…  Pragmatic Version Control using CVS Pragmatic Version Control using CVS

July 2011 CMSC 341 CVS/Ant 25 CVS Terminology Repository – the place where resources (files) are stored Checkout – copy resources from the repository and create a working copy Checkin/Commit – place resources from your working copy into the repository Add – place a resource under version control Remove – delete a resource from version control Update – pull down changes from the repository into your working copy

July 2011 CMSC 341 CVS/Ant 26 Using CVS in this course See ate/341/fall12/projects/CVS.html ate/341/fall12/projects/CVS.html For additional slides about CVS submission via Eclipse: e/341/Lectures/CVS/intro-to-cvs.ppt