title: Install AspectJ Eclipse
body: <p>I'm trying to get started with aspect oriented programming.
  I'm using latest eclipse (currently 12-2019)</p>
  
  <pre><code>public aspect Observer {
  
  }
  </code></pre>
  
  <p>This Results in an error
  <code>Syntax error on token "aspect", interface expected</code></p>
  
  <p>According to <em><a href="https://www.eclipse.org/ajdt/downloads" rel="nofollow noreferrer">https://www.eclipse.org/ajdt/downloads</a></em></p>
  
  <p>I added
  <em><a href="http://download.eclipse.org/tools/ajdt/43/update" rel="nofollow noreferrer">http://download.eclipse.org/tools/ajdt/43/update</a></em></p>
  
  <p>as an update site to eclipse</p>
  
  <p><a href="https://i.stack.imgur.com/YGOP0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/YGOP0.png" alt="Eclipse AspectJ Install Site"></a></p>
  
  <p>However eclipse tells me that some parts could not be installed </p>
  
  <p><a href="https://i.stack.imgur.com/lbltA.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lbltA.png" alt="Install Error"></a></p>
  
  <p>It looks Like some parts are missing</p>
  
  <blockquote>
    <p>Cannot complete the install because one or more required items could
    not be found.   Software being installed: AspectJ Development Tools
    2.2.3.e43x-RELEASE-20130627-0800 (org.eclipse.ajdt.feature.group 2.2.3.e43x-RELEASE-20130627-0800)   Missing requirement: AspectJ 1.7.3.20130613144500-a (org.aspectj.ajde 1.7.3.20130613144500-a) requires 'osgi.bundle; org.eclipse.core.runtime.compatibility 0.0.0'
    but it could not be found   Cannot satisfy dependency:
        From: AspectJ Compiler 1.7.3.20130613144500-a (org.aspectj.feature.group 1.7.3.20130613144500-a)
        To: org.eclipse.equinox.p2.iu; org.aspectj.ajde [1.7.3.20130613144500-a,1.7.3.20130613144500-a]   Cannot satisfy
    dependency:
        From: AspectJ Development Tools 2.2.3.e43x-RELEASE-20130627-0800 (org.eclipse.ajdt.feature.group 2.2.3.e43x-RELEASE-20130627-0800)
        To: org.eclipse.equinox.p2.iu; org.aspectj.feature.group [1.7.3.20130613144500-a,1.7.3.20130613144500-a]</p>
  </blockquote>
  
  <p>How could I Get Aspects to run in Eclipse?
  Could you help me out?</p>