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| <html> |
| <head> |
| <title>Tutorial: Hello World with Apache Ant</title> |
| <link rel="stylesheet" type="text/css" href="stylesheets/style.css"> |
| </head> |
| <body> |
| <h1>Tutorial: Hello World with Apache Ant</h1> |
| |
| <p>This document provides a step by step tutorial for starting java programming with Apache Ant. |
| It does <b>not</b> contain deeper knowledge about Java or Ant. This tutorial has the goal |
| to let you see, how to do the easiest steps in Ant.</p> |
| |
| |
| |
| <h2>Content</h2> |
| <p><ul> |
| <li><a href="#prepare">Preparing the project</a></li> |
| <li><a href="#four-steps">Enhance the build file</a></li> |
| <li><a href="#enhance">Enhance the build file</a></li> |
| <li><a href="#ext-libs">Using external libraries</a></li> |
| <li><a href="#resources">Resources</a></li> |
| </ul></p> |
| |
| |
| <a name="prepare"></a> |
| <h2>Preparing the project</h2> |
| <p>We want to separate the source from the generated files, so our java source files will |
| be in <tt>src</tt> folder. All generated files should be under <tt>build</tt>, and there |
| splitted into several subdirectories for the individual steps: <tt>classes</tt> for our compiled |
| files and <tt>jar</tt> for our own JAR-file.</p> |
| <p>We have to create only the <tt>src</tt> directory. (Because I am working on Windows, here is |
| the win-syntax - translate to your shell):</p> |
| |
| <pre class="code"> |
| md src |
| </pre> |
| |
| <p>The following simple Java class just prints a fixed message out to STDOUT, |
| so just write this code into <tt>src\oata\HelloWorld.java</tt>.</p> |
| |
| <pre class="code"> |
| package oata; |
| |
| public class HelloWorld { |
| public static void main(String[] args) { |
| System.out.println("Hello World"); |
| } |
| } |
| </pre> |
| |
| <p>Now just try to compile and run that: |
| <pre class="code"> |
| md build\classes |
| javac -sourcepath src -d build\classes src\oata\HelloWorld.java |
| java -cp build\classes oata.HelloWorld |
| </pre> |
| which will result in |
| <pre class="output"> |
| Hello World |
| </pre> |
| </p> |
| |
| <p>Creating a jar-file is not very difficult. But creating a <i>startable</i> jar-file needs more steps: create a |
| manifest-file containing the start class, creating the target directory and archiving the files.</p> |
| <pre class="code"> |
| echo Main-Class: oata.HelloWorld>myManifest |
| md build\jar |
| jar cfm build\jar\HelloWorld.jar myManifest -C build\classes . |
| java -jar build\jar\HelloWorld.jar |
| </pre> |
| |
| <p><b>Note:</b> Do not have blanks around the >-sign in the <tt>echo Main-Class</tt> instruction because it would |
| falsify it!</p> |
| |
| |
| <a name="four-steps"></a> |
| <h2>Four steps to a running application</h2> |
| <p>After finishing the java-only step we have to think about our build process. We <i>have</i> to compile our code, otherwise we couldn't |
| start the program. Oh - "start" - yes, we could provide a target for that. We <i>should</i> package our application. |
| Now it's only one class - but if you want to provide a download, no one would download several hundreds files ... |
| (think about a complex Swing GUI - so let us create a jar file. A startable jar file would be nice ... And it's a |
| good practise to have a "clean" target, which deletes all the generated stuff. Many failures could be solved just |
| by a "clean build".</p> |
| |
| <p>By default Ant uses <tt>build.xml</tt> as the name for a buildfile, so our <tt>.\build.xml</tt> would be:</p> |
| <pre class="code"> |
| <project> |
| |
| <target name="clean"> |
| <delete dir="build"/> |
| </target> |
| |
| <target name="compile"> |
| <mkdir dir="build/classes"/> |
| <javac srcdir="src" destdir="build/classes"/> |
| </target> |
| |
| <target name="jar"> |
| <mkdir dir="build/jar"/> |
| <jar destfile="build/jar/HelloWorld.jar" basedir="build/classes"> |
| <manifest> |
| <attribute name="Main-Class" value="oata.HelloWorld"/> |
| </manifest> |
| </jar> |
| </target> |
| |
| <target name="run"> |
| <java jar="build/jar/HelloWorld.jar" fork="true"/> |
| </target> |
| |
| </project> |
| </pre> |
| |
| <p>Now you can compile, package and run the application via</p> |
| <pre class="code"> |
| ant compile |
| ant jar |
| ant run |
| </pre> |
| <p>Or shorter with</p> |
| <pre class="code"> |
| ant compile jar run |
| </pre> |
| |
| <p>While having a look at the buildfile, we will see some similar steps between Ant and the java-only commands: |
| <table> |
| <tr> |
| <th>java-only</th> |
| <th>Ant</th> |
| </tr> |
| <tr> |
| <td valign="top"><pre class="code"> |
| md build\classes |
| javac |
| -sourcepath src |
| -d build\classes |
| src\oata\HelloWorld.java |
| echo Main-Class: oata.HelloWorld>mf |
| md build\jar |
| jar cfm |
| build\jar\HelloWorld.jar |
| mf |
| -C build\classes |
| . |
| |
| |
| |
| java -jar build\jar\HelloWorld.jar |
| </pre></td> |
| <td valign="top"><pre class="code"> |
| <mkdir dir="build/classes"/> |
| <javac |
| srcdir="src" |
| destdir="build/classes"/> |
| <i><!-- automatically detected --></i> |
| <i><!-- obsolete; done via manifest tag --></i> |
| <mkdir dir="build/jar"/> |
| <jar |
| destfile="build/jar/HelloWorld.jar" |
| |
| basedir="build/classes"> |
| <manifest> |
| <attribute name="Main-Class" value="oata.HelloWorld"/> |
| </manifest> |
| </jar> |
| <java jar="build/jar/HelloWorld.jar" fork="true"/> |
| </pre></td> |
| </tr></table> |
| </p> |
| |
| |
| |
| <a name="enhance"></a> |
| <h2>Enhance the build file</h2> |
| <p>Now we have a working buildfile we could do some enhancements: many time you are referencing the |
| same directories, main-class and jar-name are hard coded, and while invocation you have to remember |
| the right order of build steps.</p> |
| <p>The first and second point would be addressed with <i>properties</i>, the third with a special property - an attribute |
| of the <project>-tag and the fourth problem can be solved using dependencies.</p> |
| |
| |
| <pre class="code"> |
| <project name="HelloWorld" basedir="." default="main"> |
| |
| <property name="src.dir" value="src"/> |
| |
| <property name="build.dir" value="build"/> |
| <property name="classes.dir" value="${build.dir}/classes"/> |
| <property name="jar.dir" value="${build.dir}/jar"/> |
| |
| <property name="main-class" value="oata.HelloWorld"/> |
| |
| |
| |
| <target name="clean"> |
| <delete dir="${build.dir}"/> |
| </target> |
| |
| <target name="compile"> |
| <mkdir dir="${classes.dir}"/> |
| <javac srcdir="${src.dir}" destdir="${classes.dir}"/> |
| </target> |
| |
| <target name="jar" depends="compile"> |
| <mkdir dir="${jar.dir}"/> |
| <jar destfile="${jar.dir}/${ant.project.name}.jar" basedir="${classes.dir}"> |
| <manifest> |
| <attribute name="Main-Class" value="${main-class}"/> |
| </manifest> |
| </jar> |
| </target> |
| |
| <target name="run" depends="jar"> |
| <java jar="${jar.dir}/${ant.project.name}.jar" fork="true"/> |
| </target> |
| |
| <target name="clean-build" depends="clean,jar"/> |
| |
| <target name="main" depends="clean,run"/> |
| |
| </project> |
| </pre> |
| |
| |
| <p>Now it's easier, just do a <tt class="code">ant</tt> and you will get</p> |
| <pre class="output"> |
| Buildfile: build.xml |
| |
| clean: |
| |
| compile: |
| [mkdir] Created dir: C:\...\build\classes |
| [javac] Compiling 1 source file to C:\...\build\classes |
| |
| jar: |
| [mkdir] Created dir: C:\...\build\jar |
| [jar] Building jar: C:\...\build\jar\HelloWorld.jar |
| |
| run: |
| [java] Hello World |
| |
| main: |
| |
| BUILD SUCCESSFUL |
| </pre> |
| |
| |
| <a name="ext-libs"></a> |
| <h2>Using external libraries</h2> |
| <p>Somehow told us not to use syso-statements. For log-Statements we should use a Logging-API - customizable on a high |
| degree (including switching off during usual life (= not development) execution). We use Log4J for that, because <ul> |
| <li>it is not part of the JDK (1.4+) and we want to show how to use external libs</li> |
| <li>it can run under JDK 1.2 (as Ant)</li> |
| <li>it's highly configurable</li> |
| <li>it's from Apache ;-)</li> |
| </ul></p> |
| <p>We store our external libraries in a new directory <tt>lib</tt>. Log4J can be |
| <a href="http://www.apache.org/dist/logging/log4j/1.2.13/logging-log4j-1.2.13.zip">downloaded [1]</a> from Logging's Homepage. |
| Create the <tt>lib</tt> directory and extract the log4j-1.2.9.jar into that lib-directory. After that we have to modify |
| our java source to use that library and our buildfile so that this library could be accessed during compilation and run. |
| </p> |
| <p>Working with Log4J is documented inside its manual. Here we use the <i>MyApp</i>-example from the |
| <a href="http://logging.apache.org/log4j/docs/manual.html">Short Manual [2]</a>. First we have to modify the java source to |
| use the logging framework:</p> |
| |
| <pre class="code"> |
| package oata; |
| |
| <b>import org.apache.log4j.Logger;</b> |
| <b>import org.apache.log4j.BasicConfigurator;</b> |
| |
| public class HelloWorld { |
| <b>static Logger logger = Logger.getLogger(HelloWorld.class);</b> |
| |
| public static void main(String[] args) { |
| <b>BasicConfigurator.configure();</b> |
| <font color="blue"><b>logger.info("Hello World");</b></font> // the old SysO-statement |
| } |
| } |
| </pre> |
| |
| <p>Most of the modifications are "framework overhead" which has to be done once. The blue line is our "old System-out" |
| statement.</p> |
| <p>Don't try to run <tt>ant</tt> - you will only get lot of compiler errors. Log4J is not inside the classpath so we have |
| to do a little work here. But do not change the CLASSPATH environment variable! This is only for this project and maybe |
| you would break other environments (this is one of the most famous mistakes when working with Ant). We introduce Log4J |
| (or to be more precise: all libraries (jar-files) which are somewhere under <tt>.\lib</tt>) into our buildfile:</p> |
| |
| <pre class="code"> |
| <project name="HelloWorld" basedir="." default="main"> |
| ... |
| <b><property name="lib.dir" value="lib"/></b> |
| |
| <b><path id="classpath"></b> |
| <b><fileset dir="${lib.dir}" includes="**/*.jar"/></b> |
| <b></path></b> |
| |
| ... |
| |
| <target name="compile"> |
| <mkdir dir="${classes.dir}"/> |
| <javac srcdir="${src.dir}" destdir="${classes.dir}" <b>classpathref="classpath"</b>/> |
| </target> |
| |
| <target name="run" depends="jar"> |
| <java fork="true" <b>classname="${main-class}"</b>> |
| <b><classpath></b> |
| <b><path refid="classpath"/></b> |
| <font color="red"><b><path location="${jar.dir}/${ant.project.name}.jar"/></b></font> |
| <b></classpath></b> |
| </java> |
| </target> |
| |
| ... |
| |
| </project> |
| </pre> |
| |
| <p>In this example we start our application not via its Main-Class manifest-attribute, because we could not provide |
| a jarname <i>and</i> a classpath. So add our class in the red line to the already defined path and start as usual. Running |
| <tt>ant</tt> would give (after the usual compile stuff):</p> |
| |
| <pre class="output"> |
| [java] 0 [main] INFO oata.HelloWorld - Hello World |
| </pre> |
| |
| <p>What's that? <ul> |
| <li><i>[java]</i> Ant task running at the moment</li> |
| <li><i>0</i> <font size="-1">sorry don't know - some Log4J stuff</font></li> |
| <li><i>[main]</i> the running thread from our application </li> |
| <li><i>INFO</i> log level of that statement</i> |
| <li><i>oata.HelloWorld</i> source of that statement</i> |
| <li><i>-</i> separator</li> |
| <li><i>Hello World</i> the message</li> |
| </ul> |
| For another layout ... have a look inside Log4J's documentation about using other PatternLayout's.</p> |
| |
| |
| <a name="config-files"> |
| <h2>Configuration files</h2> |
| <p>Why we have used Log4J? "It's highly configurable"? No - all is hard coded! But that is not the debt of Log4J - it's |
| ours. We had coded <tt>BasicConfigurator.configure();</tt> which implies a simple, but hard coded configuration. More |
| comfortable would be using a property file. In the java source delete the BasicConfiguration-line from the main() method |
| (and the related import-statement). Log4J will search then for a configuration as described in it's manual. Then create |
| a new file <tt>src/log4j.properties</tt>. That's the default name for Log4J's configuration and using that name would make |
| life easier - not only the framework knows what is inside, you too!</p> |
| |
| <pre class="code"> |
| log4j.rootLogger=DEBUG, <b>stdout</b> |
| |
| log4j.appender.<b>stdout</b>=org.apache.log4j.ConsoleAppender |
| |
| log4j.appender.<b>stdout</b>.layout=org.apache.log4j.PatternLayout |
| log4j.appender.<b>stdout</b>.layout.ConversionPattern=<font color="blue"><b>%m%n</b></font> |
| </pre> |
| |
| <p>This configuration creates an output channel ("Appender") to console named as <tt>stdout</tt> which prints the |
| message (%m) followed by a line feed (%n) - same as the earlier System.out.println() :-) Oooh kay - but we haven't |
| finished yet. We should deliver the configuration file, too. So we change the buildfile:</p> |
| |
| <pre class="code"> |
| ... |
| <target name="compile"> |
| <mkdir dir="${classes.dir}"/> |
| <javac srcdir="${src.dir}" destdir="${classes.dir}" classpathref="classpath"/> |
| <b><copy todir="${classes.dir}"></b> |
| <b><fileset dir="${src.dir}" excludes="**/*.java"/></b> |
| <b></copy></b> |
| </target> |
| ... |
| </pre> |
| |
| <p>This copies all resources (as long as they haven't the suffix ".java") to the build directory, so we could |
| start the application from that directory and these files will included into the jar.</p> |
| |
| |
| <a name="junit"> |
| <h2>Testing the class</h2> |
| <p>In this step we will introduce the usage of the JUnit [3] testframework in combination with Ant. Because Ant |
| has a built-in JUnit 3.8.2 you could start directly using it. Write a test class in <tt>src\HelloWorldTest.java</tt>: </p> |
| |
| <pre class="code"> |
| public class HelloWorldTest extends junit.framework.TestCase { |
| |
| public void testNothing() { |
| } |
| |
| public void testWillAlwaysFail() { |
| fail("An error message"); |
| } |
| |
| }</pre> |
| |
| <p>Because we dont have real business logic to test, this test class is very small: just show how to start. For |
| further information see the JUnit documentation [3] and the manual of <a href="Tasks/junit.html">junit</a> task. |
| Now we add a junit instruction to our buildfile:</p> |
| |
| <pre class="code"> |
| ... |
| |
| <path <b>id="application"</b> location="${jar.dir}/${ant.project.name}.jar"/> |
| |
| <target name="run" depends="jar"> |
| <java fork="true" classname="${main-class}"> |
| <classpath> |
| <path refid="classpath"/> |
| <b><path refid="application"/></b> |
| </classpath> |
| </java> |
| </target> |
| |
| <b><target name="junit" depends="jar"> |
| <junit printsummary="yes"> |
| <classpath> |
| <path refid="classpath"/> |
| <path refid="application"/> |
| </classpath> |
| |
| <batchtest fork="yes"> |
| <fileset dir="${src.dir}" includes="*Test.java"/> |
| </batchtest> |
| </junit> |
| </target></b> |
| |
| ... |
| |
| </pre> |
| |
| <p>We reuse the path to our own jar file as defined in run-target by |
| giving it an ID and making it globally available. |
| The <tt>printsummary=yes</tt> lets us see more detailed information than just a "FAILED" or "PASSED" message. |
| How much tests failed? Some errors? Printsummary lets us know. The classpath is set up to find our classes. |
| To run tests the <tt>batchtest</tt> here is used, so you could easily add more test classes in the future just |
| by naming them <tt>*Test.java</tt>. This is a common naming scheme.</p> |
| |
| <p>After a <tt class="code">ant junit</tt> you'll get:</p> |
| |
| <pre class="output"> |
| ... |
| junit: |
| [junit] Running HelloWorldTest |
| [junit] Tests run: 2, Failures: 1, Errors: 0, Time elapsed: 0,01 sec |
| [junit] Test HelloWorldTest FAILED |
| |
| BUILD SUCCESSFUL |
| ... |
| </pre> |
| |
| <p>We can also produce a report. Something that you (and other) could read after closing the shell .... |
| There are two steps: 1. let <junit> log the information and 2. convert these to something readable (browsable).<p> |
| |
| <pre class="code"> |
| ... |
| <b><property name="report.dir" value="${build.dir}/junitreport"/></b> |
| ... |
| <target name="junit" depends="jar"> |
| <b><mkdir dir="${report.dir}"/></b> |
| <junit printsummary="yes"> |
| <classpath> |
| <path refid="classpath"/> |
| <path refid="application"/> |
| </classpath> |
| |
| <b><formatter type="xml"/></b> |
| |
| <batchtest fork="yes" <b>todir="${report.dir}"</b>> |
| <fileset dir="${src.dir}" includes="*Test.java"/> |
| </batchtest> |
| </junit> |
| </target> |
| |
| <b><target name="junitreport"> |
| <junitreport todir="${report.dir}"> |
| <fileset dir="${report.dir}" includes="TEST-*.xml"/> |
| <report todir="${report.dir}"/> |
| </junitreport> |
| </target></b> |
| </pre> |
| |
| <p>Because we would produce a lot of files and these files would be written to the current directory by default, |
| we define a report directory, create it before running the <tt>junit</tt> and redirect the logging to it. The log format |
| is XML so <tt>junitreport</tt> could parse it. In a second target <tt>junitreport</tt> should create a browsable |
| HTML-report for all generated xml-log files in the report directory. Now you can open the ${report.dir}\index.html and |
| see the result (looks something like JavaDoc).<br> |
| Personally I use two different targets for junit and junitreport. Generating the HTML report needs some time and you dont |
| need the HTML report just for testing, e.g. if you are fixing an error or a integration server is doing a job. |
| </p> |
| |
| |
| |
| |
| <a name="resources"></a> |
| <h2>Resources</h2> |
| <pre> |
| [1] <a href="http://www.apache.org/dist/logging/log4j/1.2.13/logging-log4j-1.2.13.zip">http://www.apache.org/dist/logging/log4j/1.2.13/logging-log4j-1.2.13.zip</a> |
| [2] <a href="http://logging.apache.org/log4j/docs/manual.html">http://logging.apache.org/log4j/docs/manual.html</a> |
| [3] <a href="http://www.junit.org/index.htm">http://www.junit.org/index.htm</a> |
| </pre> |
| |
| |
| |
| |
| </body> |
| </html> |
