Ant

Introduction

Apache Ant is a Java-based build tool. Ant build files are created using XML but it also support Python scripts using Jython.

This howto was tested with Jython 2.5.0 standalone, PyAMF 0.5, Ant 1.7 and Java JDK 1.6.0_13 on Mac OSX 10.5.7.

Contents

• Ant
  • About JSR-223
  • Application Setup
  • Run Application
  • Clients
    • Python
    • Flash

About JSR-223

There are 2 ways to execute Python scripts in Ant:

• using JSR-223
• utilising the PythonInterpreter

JSR-223 enables dynamic languages to be callable via Java in a seamless manner, which is supported in Jython 2.2.1 and newer. This howto will show you how to make use of the PythonInterpreter class directly.

This style of embedding code is very similar to making use of a scripting engine, and it has the advantage of working with Jython 2.5 and newer. The JSR-223 requires the unreleased Jython 2.5.1 or newer. In order to make use of the PythonInterpreter technique, you only need to have the standalone jython.jar in your classpath, there is no need to have an extra engine involved.

Application Setup

Start out with checking whether Apache Ant is working:

ant -version

Returns the version number:

Apache Ant version 1.7.0 compiled on May 21 2009

Make a project folder:

mkdir jython-ant
cd jython-ant

Grab a copy of PyAMF and it’s documentation from Git:

git clone git://github.com/hydralabs/pyamf.git
cp -R pyamf/doc/tutorials/examples/jython/ant/embedded/* .

Copy jython.jar from your Jython 2.5 distribution folder into the project’s jython folder. Make sure you installed Jython 2.5 in standalone mode which produces a jython.jar file that contains all necessary files for your application to run without any other Jython dependencies:

mkdir jython
cp /path/to/jython2.5.x/jython.jar jython/

This jython folder is on the classpath of your application so any other .jar files you may have go in here as well.

Now copy the PyAMF source and put it in the jython/Lib folder:

mkdir jython/Lib
cp -R pyamf/pyamf jython/Lib/

Run Application

Run Ant from the project’s base folder:

ant

This will do the following for you:

• clean the build folder
• compile the src/java/org/pyamf/HelloWorld.java class containing the PythonInterpreter
• create a file called HelloWorld.jar in build/classes/org/pyamf containing the compiled Java .class file
• run the HelloWorld.jar application
• try to load the src/python/server.py script that contains the PyAMF remoting gateway for WSGI

It should print the build progress and application output:

Buildfile: build.xml

clean:

compile:
  [mkdir] Created dir: /path/to/jython-ant/build/classes
  [javac] Compiling 1 source file to /path/to/jython-ant/build/classes

jar:
  [mkdir] Created dir: /path/to/jython-ant/build/jar
    [jar] Building jar: /path/to/jython-ant/build/jar/HelloWorld.jar

run:
   [java] *sys-package-mgr*: processing new jar, '/path/to/jython-ant/jython/jython.jar'
   [java] *sys-package-mgr*: processing new jar, '/path/to/jython-ant/build/jar/HelloWorld.jar'
   ...
   [java] Running AMF gateway on http://localhost:8000

The first time you run Ant it also includes some caching messages from Jython that start with *sys-package-mgr*: processing new jar. The default folder where these cache files are stored is jython/cachedir.

The final line shows your AMF gateway is up and running.

Clients

Python

Run client.py in src/python/ which should print:

2009-07-20 00:00:32,669 INFO  [root] Connecting to http://localhost:8000
2009-07-20 00:00:32,783 INFO  [root] Hello world!

And the server running in Ant should show some debug information:

[java] 2009-07-19 23:48:59,756 DEBUG [root] remoting.decode start
[java] 2009-07-19 23:49:00,190 DEBUG [root] Remoting target: u'echo.echo'
[java] 2009-07-19 23:49:00,223 DEBUG [root] remoting.decode end
[java] 2009-07-19 23:49:00,232 INFO  [root] AMF Request: <Envelope amfVersion=0 clientType=0>
[java]  (u'/1', <Request target=u'echo.echo'>[u'Hello world!']</Request>)
[java] </Envelope>
[java] 2009-07-19 23:49:00,323 INFO  [root] AMF Response: <Envelope amfVersion=0 clientType=0>
[java]  (u'/1', <Response status=/onResult>u'Hello world!'</Response>)
[java] </Envelope>
[java] 127.0.0.1 - - [19/Jul/2009 23:49:00] "POST / HTTP/1.1" 200 44

Flash

The Hello World examples should all work with this example’s server.py.