title: How to convert an Eclipse Android project to use Ant for build?
body: <p>I have an Android project in Eclipse I would like to convert to be built with <strong>Ant</strong> instead.</p>
  
  <p>How can I achieve this? I have tried exporting an Ant build file but I'm pretty sure that's not going to work (nor does it when running ant with the exported file). I do not know much about Ant either so some explanation would also help.</p>
  
  <p>EDIT: now I seem to have managed to create the needed build file but I need to add the projects libs like admob.jar to be seen by ant and used to build.
  as I am getting the following error </p>
  
  <pre><code>        -dex:
       [echo] Converting compiled files and external libraries into C:\Users\Jason
  \Documents\Programming\Android\Android SVN\trunk\GPSAlarm\BusSnooze\bin\classes.
  dex...
      [apply]
      [apply] UNEXPECTED TOP-LEVEL EXCEPTION:
      [apply] com.android.dx.util.ExceptionWithContext
      [apply]     at com.android.dx.util.ExceptionWithContext.withContext(Exceptio
  nWithContext.java:46)
      [apply]     at com.android.dx.dex.cf.CfTranslator.processMethods(CfTranslato
  r.java:340)
      [apply]     at com.android.dx.dex.cf.CfTranslator.translate0(CfTranslator.ja
  va:131)
      [apply]     at com.android.dx.dex.cf.CfTranslator.translate(CfTranslator.jav
  a:85)
      [apply]     at com.android.dx.command.dexer.Main.processClass(Main.java:297)
  
      [apply]     at com.android.dx.command.dexer.Main.processFileBytes(Main.java:
  276)
      [apply]     at com.android.dx.command.dexer.Main.access$100(Main.java:56)
      [apply]     at com.android.dx.command.dexer.Main$1.processFileBytes(Main.jav
  a:228)
      [apply]     at com.android.dx.cf.direct.ClassPathOpener.processArchive(Class
  PathOpener.java:245)
      [apply]     at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPath
  Opener.java:130)
      [apply]     at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpe
  ner.java:108)
      [apply]     at com.android.dx.command.dexer.Main.processOne(Main.java:245)
      [apply]     at com.android.dx.command.dexer.Main.processAllFiles(Main.java:1
  83)
      [apply]     at com.android.dx.command.dexer.Main.run(Main.java:139)
      [apply]     at com.android.dx.command.dexer.Main.main(Main.java:120)
      [apply]     at com.android.dx.command.Main.main(Main.java:87)
      [apply] Caused by: java.lang.NullPointerException
      [apply]     at com.android.dx.cf.code.ConcreteMethod.&lt;init&gt;(ConcreteMethod.j
  ava:84)
      [apply]     at com.android.dx.dex.cf.CfTranslator.processMethods(CfTranslato
  r.java:243)
      [apply]     ... 14 more
      [apply] ...while processing &lt;init&gt; ()V
      [apply] ...while processing com/google/android/apps/analytics/AnalyticsRecei
  ver.class
      [apply]
      [apply] 1 error; aborting
  </code></pre>