Sample Ant Build File - JAR
this example you will see how to structure the project. If the
grows bigger, it will become a problem to manages the files if
all the files are there in the same directory.
For a easier maintenanace all the source file should be kept in
the src directory, the compressed jar file should be kept in the
dist directory and all the intermediate class files should be
kept in the build/classes directory.
dir="build/classes" /><mkdir dir="dist"
During the compilation process all the java
files in the src directory will be compiled and the generated
class files will be placed in the build/classes directory.
Since we placed all the class files under the build/classes directory,
creating jar file becomes easier, you can simply specify the basedir
attribute as "build/classes" instead of specifying basedir="."
and includes="*.class". After creating the jar file
we place it in the dist directory
srcdir="src" destdir="build/classes" />
You can use the java task to execute a class file as shown below.
The classname attribute refers to the java class to be executed
and the classpath attribute refers to the directory in which the
class is located.
all the class files and jar files are isolated, we can easily
clean the project by deleting the respective directories.
The default target is compress, so when you run the build file
the compress target will be executed.
The compress target depends on compile target which in turn depends
on the init target, so first the init target will be executed
and the two directories will be created, then the compile target
will be execute,later the jar file is created.
When you run the "ant execute" command
the execute target will be invoked. Execute target also depends
on compile target which in turn depends on init target, but now
the directories won't be created again because it already exist.
Since the java file is already compiled it won't be compiled again.
Ant checks the timestamp of the file and compiles only the updated
files. The HelloWorld.class file will be execute and the "HelloWorld!"
message will be displayed on the console.
To clean and execute the program run the "ant clean execute"
command. First the clean target will be executed and the directories
will be deleted, later the execute task will be invoked.