java - apache ant - No source files and no packages have been specified -

i tried learned apache ant tutorial apache ant - tutorial

but after created step step build file , run throws:

compile:     [javac] /home/nazar_art/workspace/de.vogella.build.ant.first/src/test/build.xml:27: warning: 'includeantruntime' not set, defaulting build.sysclasspath=last; set false repeatable builds jar:       [jar] building manifest-only jar: /home/nazar_art/workspace/de.vogella.build.ant.first/src/test/dist/de.vogella.build.test.ant.jar docs:  build failed /home/nazar_art/workspace/de.vogella.build.ant.first/src/test/build.xml:34: no source files , no packages have been specified. 

i can't understand why happened? use ubuntu 12.04 os, , eclipse indigo.

build.xml:

<?xml version="1.0"?> <project name="ant-test" default="main" basedir=".">   <!-- sets variables can later used. -->   <!-- value of property accessed via ${} -->   <property name="src.dir" location="src" />   <property name="build.dir" location="bin" />   <property name="dist.dir" location="dist" />   <property name="docs.dir" location="docs" />    <!-- deletes existing build, docs , dist directory-->   <target name="clean">     <delete dir="${build.dir}" />     <delete dir="${docs.dir}" />     <delete dir="${dist.dir}" />   </target>    <!-- creates  build, docs , dist directory-->   <target name="makedir">     <mkdir dir="${build.dir}" />     <mkdir dir="${docs.dir}" />     <mkdir dir="${dist.dir}" />   </target>    <!-- compiles java code (including usage of library junit -->   <target name="compile" depends="clean, makedir">     <javac srcdir="${src.dir}" destdir="${build.dir}">     </javac>    </target>    <!-- creates javadoc -->   <target name="docs" depends="compile">     <javadoc packagenames="src" sourcepath="${src.dir}" destdir="${docs.dir}">       <!-- define files / directory should included, include -->        <fileset dir="${src.dir}">                 <include name="**" />            </fileset>     </javadoc>   </target>    <!--creates deployable jar file  -->   <target name="jar" depends="compile">     <jar destfile="${dist.dir}\de.vogella.build.test.ant.jar" basedir="${build.dir}">       <manifest>         <attribute name="main-class" value="test.main" />       </manifest>     </jar>   </target>    <target name="main" depends="compile, jar, docs">     <description>main target</description>   </target>  </project>  

code part:

package math;  public class mymath {   public int multi(int number1, int number2) {     return number1 * number2;   } }   package test;  import math.mymath;  public class main {   public static void main(string[] args) {     mymath math = new mymath();     system.out.println("result is: " + math.multi(5, 10));   } }  

• how solve trouble?

in ant build.xml <docs> target trying generate documentation "src" package. try correct package name "math" in <javadoc packagenames="src" sourcepath="..."> packagenames="math,test". can read ant documentation has examples of javadoc task usage.