title: No support for Java 7 in Drools  ("RuntimeDroolsException: value '1.7' is not a valid language level")
body: <p>While I'm moving my project to java7, Drools starting throwing RuntimeDroolsException exception during init process. When i dig further, I found that this is happening when it validates java dialect. </p>
  
  <p>The problem is: Drools 5.1.1 compares "java.version" system property with LANGUAGE_LEVELS to validate it. LANGUAGE_LEVELS is hard-coded list of java versions till 1.6 </p>
  
  <pre><code>In org.drools.rule.builder.dialect.java.JavaDialectConfiguration,
  public static final String[]        LANGUAGE_LEVELS = new String[]{"1.5", "1.6"};
  </code></pre>
  
  <p>I didn't want to change the source code. So I added the below as a workaround to bypass java dialect validation. </p>
  
  <pre><code>Properties properties = new Properties();
  properties.setProperty( "drools.dialect.java.compiler.lnglevel","1.6" );
  PackageBuilderConfiguration cfg =
  new PackageBuilderConfiguration( properties );
  KnowledgeBuilder knowledgeBuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(cfg);
  </code></pre>
  
  <p>Is there any better way of doing this other than editing source code? </p>
  
  <p>P.S: Drools 5.1.1 is the latest production version of the drools </p>