Ant is using wrong java version

Question

I\'m using Ant 1.7.0 and installed java 1.6 which is in JAVA_HOME.

I want to build a project using java 1.5, so I\'ve exported JAVA_HOME to be my java 1.5 directory.

Answer 1

Use the following 2 properties for javac tag:

fork="yes"  
executable="full-path-to-the-javac-you-want-to-use".

Explaination of the properties can be found here

Answer 2

Run ant in verbose mode : ant -v and looks for clues.

Answer 3

Set your JAVA_HOME environment variable with the required java version (in your case java 1.5), then in build.xml use executable="${JAVA_HOME}/bin/javac" inside <javac></javac> tag .

example:

<target name="java compiler" description="Compiles the java code">
    <javac executable="${JAVA_HOME}/bin/javac" srcdir="./src" 
        destdir="${build.dir}/classes"> 
    </javac> 
</target>

Answer 4

According to the Ant Documentation, set JAVACMD environment variable to complete path to java.exe of the JRE version that you want to run Ant under.

Answer 5

According to the ant manual, setting JAVA_HOME should work - are you sure the changed setting is visible to ant?

Alternatively, you could use the JAVACMD variable.

Answer 6

By default the Ant will considered the JRE as the workspace JRE version. You need to change according to your required version by following the below.

In Eclipse:

• Right click on your build.xml click "Run As", click on "External Tool Configurations..." Select tab JRE.

• Select the JRE you are using.

• Re-run the task, it should be fine now.