Question

I want to write the Ant script that excludes the complete folder except some of the files.

I have one folder where thousands of Java files are located. Now I want to exclude that folder and I want to include two Java files out of that. How can I do that?

The below code doesn’t work for me.

<target  name="compile" >
    <javac srcdir="src" destdir="./classes"
        <exclude name="com/corporate/modes/**"/>
        <include name="com/corporate/modes/UpdatePersonalDetail.java"/>

Answer 1

To include only specific files from a folder in your javac compilation task, specify the files using the <include> element. When an <include> element is specified, only the named file (and its project dependencies) will be included in the compilation.

Example Project

Project Directory: /home/project
Source Directory: /home/project/src
Build Directory: /home/project/build

---

build.xml (located in /home/project)

<?xml version="1.0" encoding="UTF-8"?>
<project name="compile_test" basedir="." default="compile_class1">

  <property name="src.dir" value="${basedir}/src" />
  <property name="build.dir" location="${basedir}/build" />
  <property name="classes.dir" location="${build.dir}/classes" />

  <target name="init" description="Initialize the build directory.">
    <mkdir dir="${build.dir}" />
    <mkdir dir="${classes.dir}" />
  </target>

  <target name="clean" description="Delete all files created by this script.">
    <delete dir="${build.dir}" />
  </target>

  <target name="compile_class1" depends="init">
    <javac srcdir="${src.dir}" destdir="${classes.dir}"
        includeantruntime="false">
      <include name="com/mypackage/Class1.java" />
    </javac>
  </target>

  <target name="compile_class2" depends="init">
    <javac srcdir="${src.dir}" destdir="${classes.dir}"
        includeantruntime="false">
      <include name="com/mypackage/Class2.java" />
    </javac>
  </target>
</project>

---

Java Source Files

Class1.java

package com.mypackage;

public class Class1 {
  public static void main(String[] args){
    System.out.println("Class1");
  }
}

Class2.java

package com.mypackage;

public class Class2 {
  public static void main(String[] args){
    Class3 class3 = new Class3();
    System.out.println(class3.getMessage());
  }
}

Class3.java

package com.mypackage;

public class Class3 {
  public String getMessage() {
    return "The answer is 42.";
  }
}

---

Ant Output

Ant target compile_class1

$ ant clean compile_class1

Buildfile: /home/project/build.xml

clean:
   [delete] Deleting directory /home/project/build

init:
    [mkdir] Created dir: /home/project/build
    [mkdir] Created dir: /home/project/build/classes

compile_class1:
    [javac] Compiling 1 source file to /home/project/build/classes

BUILD SUCCESSFUL
Total time: 1 second

Notice that although there were three Java source files, only the file specified by the <include> element was compiled.

---

Ant target compile_class2

$ ant clean compile_class2

Buildfile: /home/project/build.xml

clean:
   [delete] Deleting directory /home/project/build

init:
    [mkdir] Created dir: /home/project/build
    [mkdir] Created dir: /home/project/build/classes

compile_class2:
    [javac] Compiling 1 source file to /home/project/build/classes

BUILD SUCCESSFUL
Total time: 1 second

In this case, although the Ant target compile_class2 only specified one file in the nested <include> element, both Class2.java and Class3.java were compiled since Class2.java depends on Class3.java. If the dependencies of Class2.java were not included in the compilation, then when attempting to execute Class2, you would receive an error that com.mypackage.Class3 could not be located.