Ant conditionally set attribute

Question

Is it possible to have a dynamically set attribute in Ant?

At the moment all of our wars have the same name: "mywar.war". I'd like to have wars built with JDK6 to be "mywar-1.6.war" and those built with JDK7 to still just be "mywar.war".

Currently:

<war warfile="${dist.dir}/mywar.war">
..
<war />

I can include the Java version like this:

<war warfile="${dist.dir}/mywar-${ant.java.version}.war">

But what I'd like to have is the logic to do something like this:

if (${ant.java.version} == "1.6") {
  war.name="mywar-${ant.java.version}";
} else {
  war.name="mywar";
}

<war warfile="${dist.dir}/${war.name}.war">

Is there a correct way to go about that?

Answer 1

The way to set properties conditionally is to use the condition task:

<condition property="war.suffix" value="-1.6" else="">
  <equals arg1="${ant.java.version}" arg2="1.6"/>
</condition>

<war warfile="${dist.dir}/mywar${war.suffix}.war">

The trick here is that the else="" means that war.suffix will be an empty string on any version other than 1.6.

Answer 2

Yes you can use some thing like that but it's not available in ant as such. You will have to download ant-contrib.jar

And then you have some thing like this

<if>
 <equals arg1="${ant.java.version}" arg2="1.6" />
 <then>
   war.name="mywar-${ant.java.version}";
 </then>
 <else>
   war.name="mywar";
 </else>
</if>

See this link for ant contrib