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passing parameters to Ant

Passing parameters from the command line to your ant build file.

You can pass parameters from the command line to your ant build file by using properties.
Using ant -Dname=value lets you define values for properties on the Ant command line.
These properties can then be used within your build file as any normal property: ${name} will put in value.

However,
Let's say that I have the following java program:
++++++++++++++
class Test {
public static void main(String argv[]) {
for (int i = 0; i < argv.lenght;i++)
System.out.println("param " + i + ": " + argv[i]);
}
}
++++++++++++++

and I have the following ant file:
++++++++++++++
<project basedir=".">
      <target name="run">
            <java fork="true" classname="Test"/>
      </target>
</project>
++++++++++++++

How do I need to modify the ant file so that executing "ant run one two three" from the command line, produces:
++++++++++++++
param 1: one
param 2: two
param 3: three
++++++++++++++

(and it works for any number of parameters)

Many thanks,
DAvid

Ajay-Singh

User nested <arg> tags
http://ant.apache.org/manual/CoreTasks/java.html

<project basedir=".">
<target name="run">
<java fork="true" classname="Test">
<arg value="one" />
<arg value="two" />
<arg value="three" />
</java>
</target>
</project>

dportabella

ASKER

Alay-Singh,

In your example, you need to define that there are exactly three parameters.

The ant file should work for any number of parameters.
That is, the number of parameters is unknown at the time of writing the ant file.

e.g. the same ant file should work for these cases:
ant run one two three
ant run one two three four
ant run one two three four five ...

DAvid

Ajay-Singh

In that case, you can define system argument and use that in ant script

ant -Dargs="one two three" run

<project basedir=".">
<target name="run">
<java fork="true" classname="Test">
<arg value="${args}" />
</java>
</target>
</project>

dportabella

ASKER

executing this:
ant -Dargs="one two three" run

results in
param 0: one two three

instead of:
param 0: one
param 1: two
param 2: three

ASKER CERTIFIED SOLUTION

Ajay-Singh

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dportabella

ASKER

Here there is another related question:
https://www.experts-exchange.com/questions/23483418/How-to-get-the-classpath-from-ant-build-file.html

Thanks,
DAvid