Index: /applications/editors/josm/plugins/OpeningHoursEditor/build.xml
===================================================================
--- /applications/editors/josm/plugins/OpeningHoursEditor/build.xml	(revision 35377)
+++ /applications/editors/josm/plugins/OpeningHoursEditor/build.xml	(revision 35378)
@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
-<project name="OpeningHoursEditor" default="dist" basedir=".">
+<project name="OpeningHoursEditor" default="dist" basedir="." xmlns:ivy="antlib:org.apache.ivy.ant">
     <!-- enter the SVN commit message -->
     <property name="commit.message" value="fixed main version"/>
@@ -16,12 +16,10 @@
     <import file="../build-common.xml"/>
 	
-    <property name="javacc.home" location="../00_core_tools"/>
 	<property name="parser.dir" location="${plugin.src.dir}/org/openstreetmap/josm/plugins/ohe/parser"/>
 	
     <target name="javacc" depends="init" unless="javacc.notRequired">
-        <exec append="false" executable="java" failifexecutionfails="true">
-            <arg value="-cp"/>
-            <arg value="${javacc.home}/javacc.jar"/>
-            <arg value="javacc"/>
+        <ivy:cachepath file="${core.tools.ivy}" pathid="javacc.classpath" conf="javacc"/>
+        <java classname="javacc" fork="true" failonerror="true">
+            <classpath refid="javacc.classpath"/>
             <arg value="-JDK_VERSION=1.8"/>
             <arg value="-GRAMMAR_ENCODING=UTF-8"/>
@@ -29,5 +27,5 @@
             <arg value="-OUTPUT_DIRECTORY=${parser.dir}"/>
             <arg value="${parser.dir}/OpeningTimeCompiler.jj"/>
-        </exec>
+        </java>
     </target>
 
Index: /applications/editors/josm/plugins/build-common.xml
===================================================================
--- /applications/editors/josm/plugins/build-common.xml	(revision 35377)
+++ /applications/editors/josm/plugins/build-common.xml	(revision 35378)
@@ -27,4 +27,5 @@
     <property name="jformatstring.jar"      location="../00_core_tools/spotbugs/jFormatString-3.0.0.jar"/>
     <property name="annotations.jar"        location="../00_core_tools/spotbugs/spotbugs-annotations.jar"/>
+    <property name="core.tools.ivy"         location="../00_core_tools/ivy.xml"/>
     <property name="plugin.tools.dir"       location="../00_tools"/>
     <property name="plugin.build.dir"       location="build"/>
@@ -663,5 +664,5 @@
 
     <target name="spotbugs" depends="compile">
-        <ivy:cachepath file="../00_core_tools/ivy.xml" pathid="spotbugs.classpath" conf="spotbugs"/>
+        <ivy:cachepath file="${core.tools.ivy}" pathid="spotbugs.classpath" conf="spotbugs"/>
         <taskdef name="spotbugs" classname="edu.umd.cs.findbugs.anttask.FindBugsTask" classpath="${toString:spotbugs.classpath}"/>
         <spotbugs output="xml"
Index: /applications/editors/josm/plugins/comfort0/build.xml
===================================================================
--- /applications/editors/josm/plugins/comfort0/build.xml	(revision 35377)
+++ /applications/editors/josm/plugins/comfort0/build.xml	(revision 35378)
@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
-<project name="comfort0" default="dist" basedir=".">
+<project name="comfort0" default="dist" basedir="." xmlns:ivy="antlib:org.apache.ivy.ant">
 
     <!-- enter the *lowest* JOSM version this plugin is currently compatible with -->
@@ -15,13 +15,11 @@
     <import file="../build-common.xml"/>
 
-    <property name="javacc.home" location="../00_core_tools"/>
     <property name="parser.dir" location="src/net/simon04/comfort0/level0l"/>
     <target name="pre-compile" depends="javacc"/>
     <target name="javacc" depends="init" unless="javacc.notRequired">
+        <ivy:cachepath file="${core.tools.ivy}" pathid="javacc.classpath" conf="javacc"/>
         <mkdir dir="${parser.dir}/parsergen"/>
-        <exec append="false" executable="java" failifexecutionfails="true">
-            <arg value="-cp"/>
-            <arg value="${javacc.home}/javacc.jar"/>
-            <arg value="javacc"/>
+        <java classname="javacc" fork="true" failonerror="true">
+            <classpath refid="javacc.classpath"/>
             <arg value="-DEBUG_PARSER=false"/>
             <arg value="-DEBUG_TOKEN_MANAGER=false"/>
@@ -30,5 +28,5 @@
             <arg value="-OUTPUT_DIRECTORY=${parser.dir}/parsergen"/>
             <arg value="${parser.dir}/Level0LParser.jj"/>
-        </exec>
+        </java>
     </target>