Hello World using Apache ANT
· 3 min read
Old way of compile a project, making jar and running the jar
Project Structure
Make project structure using command prompt like
H:\>md DemoProject
H:\>md DemoProject\src\hello
H:\>md DemoProject\build\classes
Make a java class
Now make a simple java class HelloWorld
package hello;
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello World");
}
}
Compile the code
Compile the java cod using the command below
H:\>javac -sourcepath DemoProject\src -d DemoProject\build\classes DemoProject\src\hello\HelloWorld.java
Make the jar
To make the jar file we need to create manifest file containing the information of class with contain main method.
H:\>cd DemoProject
H:\DemoProject>md build\jar
H:\DemoProject>jar cfm build\jar\HelloWorld.jar myManifest -C build\classes .
Run the code
Now we can run our HelloWorld jar file using the command below.
H:\DemoProject>java -jar build\jar\HelloWorld.jar Hello World
Now doing with Smarter way using Ant
By using ant we just need to execute 4 steps.
Create only source (src) directory and place HelloWorld.java in to hello folder and manifest file parallel to src folder do not need to create build directory, it will created by ant.
H:\>md DemoProject
H:\>md DemoProject\src\hello
Step 1:
Create a build.xml file (By default Ant uses build.xml) in to DemoProject directory (parallel to the src directory)
<project>
<target name="clean">
</target>
<target name="compile">
<mkdir dir="build/classes">
<javac srcdir="src" destdir="build/classes"></javac>
</mkdir>
</target>
<target name="jar">
<mkdir dir="build/jar">
<jar destfile="build/jar/HelloWorld.jar" basedir="build/classes">
<manifest>
<attribute name="Main-Class" value="hello.HelloWorld"></attribute>
</manifest>
</jar>
</mkdir>
</target>
<target name="run">
<java jar="build/jar/HelloWorld.jar" fork="true"></java>
</target>
</project>
Step 2:
Compile the code (move to the DemoProject directory before running the commands)
H:\>cd DemoProject
H:\DemoProject>ant compile
Buildfile: H:\DemoProject\build.xml
compile:
[mkdir] Created dir: H:\DemoProject\build\classes
[javac] H:\DemoProject\build.xml:9: warning: 'includeantruntime' was not set
, defaulting to build.sysclasspath=last; set to false for repeatable builds
[javac] Compiling 1 source file to H:\DemoProject\build\classes
BUILD SUCCESSFUL
Total time: 8 seconds
Step 3
Make the jar (pack the code)
H:\DemoProject>ant jar
Buildfile: H:\DemoProject\build.xml
jar:
[mkdir] Created dir: H:\DemoProject\build\jar
[jar] Building jar: H:\DemoProject\build\jar\HelloWorld.jar
BUILD SUCCESSFUL
Total time: 4 seconds
Step 4:
Run the code
H:\DemoProject>ant run
Buildfile: H:\DemoProject\build.xml
run:
[java] Hello World
BUILD SUCCESSFUL
Total time: 4 seconds
Now you can see that using ANT makes our work easy and simpler than old technique. We can also execute all these commands in one line like this
H:\DemoProject>ant compile jar run
Buildfile: H:\DemoProject\build.xml
compile:
[mkdir] Created dir: H:\DemoProject\build\classes
[javac] H:\DemoProject\build.xml:9: warning: 'includeantruntime' was not set
, defaulting to build.sysclasspath=last; set to false for repeatable builds
[javac] Compiling 1 source file to H:\DemoProject\build\classes
jar:
[mkdir] Created dir: H:\DemoProject\build\jar
[jar] Building jar: H:\DemoProject\build\jar\HelloWorld.jar
run:
[java] Hello World
BUILD SUCCESSFUL
Total time: 11 seconds
Hope you like this post.
I used apache reference manual for this blog its good and simple. Use Apache manual for depth knowledge.