Sunday, September 13, 2015

Ant built-in Properties

This is a simple example that illustrates how to find the basedir name, file name, project name, ant version, java version, operating system name, ant home directory name, java home directory name, user home directory name and user name. Ant provides you with certain built-in properties that you may find useful during your build process. The following table shows the property name and it's description.
Ant's built-in properties:
Property
Description
ant.file
The absolute path of the build file
ant.project.name
The name of the project as set in the element's name attribute.
ant.home
The root directory of ant
ant.version
The version of this ant installation. This is not just the version number and includes information such as the compilation date.
ant.java.version
The version of the java that ant uses
basedir
The absolute path of the project
os.name
Operating system name
java.home
Java home directory name
user.home
User directory name
user.name
User name
Source code of build.xml:
"1.0"?>

"AntProperties" default="echo" basedir=".">

"echo">
"The operating system is: ${os.name}"/>


"The home path is: ${basedir}"/>


"The file name is: ${ant.file}"/>


"The Project name is: ${ant.project.name}"/>
"The Ant home directory is: ${ant.home}"/>
"The Ant version is: ${ant.version}"/>
"The Java version is: ${ant.java.version}"/>


"The Java home directory is: ${java.home}"/>
"The User home directory is: ${user.home}"/>
"The User name is: ${user.name}"/>


Run this program - the following output will be displayed:

Ant Part 2 build.xml file

This example shows how to generate the build.xml file. You may say that build.xml file is the backbone of ANT (Another Neat Tool) technology. Each build.xml file contains only one project name and at least one target. The project tag has only three attributes:
Project
Attribute
Description
Requirement
name
project name
not necessary
default
target name which called by default
not necessary
basedir
the base directory having all path, it contain absolute path
not necessary
The project tag is used to create our project and its attributes are used to handle further processing of the project. The name attribute is used to specify the project name and the default attribute is used to specify which target will be called as default when the program will run and the basedir attribute is used to calculate the absolute path of the parent directory.
An another tag is Target tag which has following five attributes:
Target
Attribute
Description
Requirement
name
target name
necessary
depends
depends on another target
not necessary
if
the name of the property that must be set in order for this target to execute.
not necessary
unless
the name of the property that must not be set in order for this target to execute.
not necessary
description
short description about target
not necessary

In the target tag, name attribute is used for target name and the depends attribute is used to give sequence of target, i.e., which target will execute first, one target may depend on one or more other targets. The if attribute is used in case of condition, whether property exists or not; then this target will be executed and unless attribute is used as like else condition whether property does not exist, the target will not be executed and the description attribute is used for only giving details about target.
Next tag is property tag which has following four attribute:
Property
Attribute
Description
Requirement
name
name of the property, which is case-sensitive
not necessary
value
name of task attribute, this is done by placing the property name between "${"name }" in the attribute value
necessary
location
it contain property name
not necessary
file
name of the property file
not necessary

In the property tag, name attribute is used for property name; it is case sensitive. The value tag is used to give the task which will be the name of property in this format "${name}", and the location tag is used to specify the location of task where it performs and the file tag is used to import all properties of ant file. The complete build.xml file structure is as follows:
























The above build.xml file is used to create directory, compile source code, create jar file and clean the directory if already exists. To check the program, simply copy and paste the above code and give appropriate path; then run with ant command on the command prompt. The output is as follows:
The output shows that a jar file named roseindia.jar is created but in this jar file only manifest file is created. When you make a java file in the src folder and run with ant command, the jar file is created completely.
class Hello
{
public static void main(String args[]){
System.out.println("sandeep kumar suman");
}
}
To check your program, compile it with ant command on the console; then the following output will be displayed: