Monday, July 16, 2018

Apache Ant 1.9.13 and 1.10.5 released - Supports Java 11 single-file source programs

We just released 1.9.13 and 1.10.5 versions of Apache Ant. As usual, you can download it from the Ant project download page.

Both these versions are mainly bug fix releases. The 1.10.5 version however has a new enhancement to the "java" task. As I blogged previously - Java 11 introduces a new feature where you can execute single-file Java programs without having to explicitly compile them first. Ant 1.10.5 release now supports this feature through a new "sourcefile" attribute in the "java" task. More about it can be found the manual of that task.

A simple usage example of this new feature of the "java" task is as follows:

<project default="launch-java" name="Java 11 - launch single-file source program">

 <target name="launch-java"
            description="Simple example of single-file source program execution,
             introduced in Java 11">

        <!-- Make sure Java 11 version is being used -->
        <condition property="java11">
            <javaversion atleast="11"/>
        <fail unless="java11">Java 11 runtime version is necessary to run this example</fail>        

        <mkdir dir="${basedir}/javasource"/>
        <!-- Write out simple Java code into a file -->
        <echo file="${basedir}/javasource/">
            import java.nio.file.Files;
            import java.nio.file.Paths;
            public class HelloWorld {
                public static void main(String[] args) throws Exception {
                    System.out.println("Hello world, " + args[0] + "!");
        <!-- launch the Java source file, using the "sourcefile" attribute -->
        <java sourcefile="${basedir}/javasource/" fork="true" failonerror="true" logerror="true">
            <arg value="Java 11"/>

As you'll notice, the build file uses the "java" task to set the "sourcefile" attribute to point to a Java source file. The rest of the usage details of the "java" task, including passing arguments to the program, continue to remain the same as before.

When you run "ant" on this build file, you should see the following output:

[java] Hello world, Java 11!

Of course, you will need to use a Java 11 binary to run this against. You can get the early accessible Java 11 binary from here.

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