merge bug19294 into default

Author: Matthias Radestock

build.xml

@@ -27,8 +27,22 @@
   </path>
 
   <property name="AMQP_SPEC_JSON_PATH" value="${codegen.dir}/amqp-${spec.version}.json"/>
-
-  <target name="amqp-generate" description="generate AMQP.java and AMQImpl.java from AMQP spec">
+  
+  <target name="amqp-generate-check" description="check if codegen needs to be run">
+    <uptodate property="amqp.generate.notRequired">
+      <srcfiles file="codegen.py"/>
+      <srcfiles dir="${codegen.dir}">
+        <include name="*" />
+      </srcfiles>
+      <compositemapper>
+        <mapper type="merge" to="${basedir}/${src.generated}/com/rabbitmq/client/impl/AMQImpl.java" />
+        <mapper type="merge" to="${basedir}/${src.generated}/com/rabbitmq/client/AMQP.java" />
+      </compositemapper>
+    </uptodate>
+  </target>
+  
+  <target name="amqp-generate" depends="amqp-generate-check"
+    unless="amqp.generate.notRequired" description="generate AMQP.java and AMQImpl.java from AMQP spec">
     <mkdir dir="${src.generated}/com/rabbitmq/client/"/>
     <exec dir="." executable="python" output="${src.generated}/com/rabbitmq/client/AMQP.java">
       <arg line="codegen.py"/>