New Launch facility. Separate jar now can be used to launch Ant which

takes over some of the functionality traditionally found in the Ant launch
scripts.


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@274724 13f79535-47bb-0310-9956-ffa450edef68

build.xml

@@ -18,12 +18,31 @@
   <property environment="env"/>
 
 
+  <!--
+       ===================================================================
+         Set the properties that control names and versions
+       ===================================================================
+  -->
   <property name="Name" value="Apache Ant"/>
   <property name="name" value="ant"/>
   <property name="version" value="1.6alpha"/>
-  <property name="manifest-version" value="1.5.9"/>
+  <property name="manifest-version" value="1.6"/>
   <property name="bootstrap.jar" value="ant-bootstrap.jar"/>
+  
+  <property name="ant.package" value="org/apache/tools/ant"/>
+  <property name="optional.package" value="${ant.package}/taskdefs/optional"/>
+  <property name="optional.type.package" value="${ant.package}/types/optional"/>
+  <property name="apache.resolver.type.package" value="${ant.package}/types/resolver"/>
+  <property name="util.package" value="${ant.package}/util"/>
+  <property name="regexp.package" value="${util.package}/regexp"/>
+  
+  <property name="optional.jars.prefix" value="ant"/>
 
+  <!--
+       ===================================================================
+         Set the properties that control various build options
+       ===================================================================
+  -->
   <property name="debug" value="true"/>
   <property name="chmod.fail" value="true"/>
   <property name="chmod.maxparallel" value="250"/>
@@ -33,6 +52,8 @@
   <property name="junit.fork" value="false"/>
   <property name="junit.filtertrace" value="off"/>
   <property name="junit.summary" value="no"/>
+  <property name="test.haltonfailure" value="yes" />
+  <property name="unfiltered.files" value="**/*.gif,**/*.jpg,**/*.ico,**/*.pdf"/>
 
   <!--
        ===================================================================
@@ -47,20 +68,8 @@
   <property name="etc.dir" value="src/etc"/>
   <property name="tests.dir" value="src/testcases"/>
   <property name="tests.etc.dir" value="src/etc/testcases"/>
-  <property name="test.haltonfailure" value="yes" />
-
-  <property name="ant.package" value="org/apache/tools/ant"/>
-  <property name="optional.package" value="${ant.package}/taskdefs/optional"/>
-  <property name="optional.type.package" value="${ant.package}/types/optional"/>
-  <property name="apache.resolver.type.package" value="${ant.package}/types/resolver"/>
-  <property name="util.package" value="${ant.package}/util"/>
-  <property name="regexp.package" value="${util.package}/regexp"/>
-
   <property name="manifest" value="src/etc/manifest"/>
 
-  <property name="unfiltered.files" value="**/*.gif,**/*.jpg,**/*.ico,**/*.pdf"/>
-
-
   <!--
        ===================================================================
          Set the properties for the build area
@@ -74,8 +83,12 @@
   <property name="build.tests" value="${build.dir}/testcases"/>
   <property name="build.tests.javadocs" value="${build.dir}/javadocs.test/"/>
   <property name="manifest.tmp" value="${build.dir}/optional.manifest"/>
-  <property name="optional.jars.prefix" value="ant"/>
 
+  <!--
+       ===================================================================
+         Set the paths used in the build
+       ===================================================================
+  -->
   <path id="classpath">
   </path>
 
@@ -90,7 +103,8 @@
     <pathelement location="${tests.etc.dir}"/>
     <path refid="classpath"/>
   </path>
-<!--   turn this path into a string which is passed to the tests -->
+  
+  <!-- turn this path into a string which is passed to the tests -->
   <property name="tests-classpath.value"
             refid="tests-classpath"/>
 
@@ -113,8 +127,6 @@
   <property name="src.dist.docs" value="${src.dist.dir}/docs"/>
   <property name="src.dist.lib" value="${src.dist.dir}/lib"/>
 
-
-
   <!--
        ===================================================================
          Set up selectors to be used by javac, junit and jar to exclude
@@ -128,6 +140,7 @@
       <filename name="${optional.package}/extension/**"/>
     </or>
   </selector>
+  
   <selector id="needs.jdk1.4+">
     <or>
       <filename name="${regexp.package}/Jdk14Regexp*"/>
@@ -142,9 +155,11 @@
       <filename name="${optional.package}/Javah*"/>
     </or>
   </selector>
+  
   <selector id="needs.sun.uue">
     <filename name="${ant.package}/taskdefs/email/UUMailer*"/>
   </selector>
+  
   <selector id="needs.sun.b64">
     <or>
       <filename name="${optional.package}/splash/SplashTask*"/>
@@ -161,27 +176,34 @@
       <filename name="${ant.package}/types/XMLCatalogBuildFileTest*"/>
     </or>
   </selector>
+  
   <selector id="needs.xalan1">
     <or>
       <filename name="${optional.package}/XalanLiaison*"/>
       <filename name="${optional.package}/junit/Xalan1Executor*"/>
     </or>
   </selector>
+  
   <selector id="needs.xalan2">
     <filename name="${optional.package}/junit/Xalan2Executor*"/>
   </selector>
+  
   <selector id="needs.xslp">
     <filename name="${optional.package}/XslpLiaison*"/>
   </selector>
+  
   <selector id="needs.apache.resolver">
     <filename name="${apache.resolver.type.package}/**"/>
   </selector>
+  
   <selector id="needs.junit">
     <filename name="${optional.package}/junit/**"/>
   </selector>
+  
   <selector id="needs.jakarta.regexp">
     <filename name="${regexp.package}/JakartaRegexp*"/>
   </selector>
+  
   <selector id="needs.jakarta.oro">
     <or>
       <filename name="${regexp.package}/JakartaOro*"/>
@@ -189,6 +211,7 @@
       <filename name="${optional.package}/metamata/MAudit*"/>
     </or>
   </selector>
+  
   <selector id="needs.jakarta.bcel">
     <or>
       <filename name="${ant.package}/filters/util/JavaClassHelper*"/>
@@ -196,12 +219,15 @@
       <filename name="${optional.type.package}/depend/ClassFileSetTest*"/>
     </or>
   </selector>
+  
   <selector id="needs.jakarta.log4j">
     <filename name="${ant.package}/listener/Log4jListener*"/>
   </selector>
+  
   <selector id="needs.commons.logging">
     <filename name="${ant.package}/listener/CommonsLoggingListener*"/>
   </selector>
+  
   <selector id="needs.bsf">
     <or>
       <filename name="${optional.package}/Script*"/>
@@ -209,32 +235,40 @@
       <filename name="${optional.type.package}/Script*"/>
     </or>
   </selector>
+  
   <selector id="needs.stylebook">
     <filename name="${optional.package}/StyleBook*"/>
   </selector>
+  
   <selector id="needs.javamail">
     <or>
       <filename name="${ant.package}/taskdefs/email/MimeMailer*"/>
     </or>
   </selector>
+  
   <selector id="needs.icontract">
     <filename name="${optional.package}/IContract*"/>
   </selector>
+  
   <selector id="needs.netrexx">
     <filename name="${optional.package}/NetRexxC*"/>
   </selector>
+  
   <selector id="needs.weblogic.ejbc">
     <filename name="${optional.package}/ejb/Ejbc*"/>
   </selector>
+  
   <selector id="needs.weblogic.ddcreator">
     <filename name="${optional.package}/ejb/DDCreator*"/>
   </selector>
+  
   <selector id="needs.weblogic.server">
     <or>
       <filename name="${optional.package}/ejb/WLRun*"/>
       <filename name="${optional.package}/ejb/WLStop*"/>
     </or>
   </selector>
+  
   <selector id="needs.commons.net">
     <or>
       <filename name="${optional.package}/net/FTP*"/>
@@ -242,40 +276,54 @@
       <filename name="${optional.package}/net/TelnetTask*"/>
     </or>
   </selector>
+  
   <selector id="needs.starteam">
     <or>
       <filename name="${optional.package}/scm/AntStarTeam*"/>
       <filename name="${optional.package}/starteam/*"/>
     </or>
   </selector>
+  
   <selector id="needs.vaj">
     <filename name="${optional.package}/ide/VAJ*"/>
   </selector>
+  
   <selector id="needs.antlr">
     <filename name="${optional.package}/ANTLR*"/>
   </selector>
+  
   <selector id="needs.jmf">
     <filename name="${optional.package}/sound/*"/>
   </selector>
+  
   <selector id="needs.jai">
     <or>
       <filename name="${optional.package}/image/*"/>
       <filename name="${ant.package}/types/optional/image/*"/>
     </or>
   </selector>
+  
   <selector id="needs.jdepend">
     <filename name="${optional.package}/jdepend/*"/>
   </selector>
+  
   <selector id="needs.swing">
     <filename name="${optional.package}/splash/*"/>
   </selector>
+  
   <selector id="needs.jsch">
     <filename name="${optional.package}/ssh/*"/>
   </selector>
+
+  <selector id="ant.launcher">
+    <filename name="${ant.package}/launch/**/*"/>
+  </selector>
+  
   <patternset id="onlinetests">
     <exclude name="**/GetTest.java" if="offline"/>
     <exclude name="**/SignJarTest.java" if="offline"/>
   </patternset>
+  
   <patternset id="teststhatfail">
     <exclude name="${optional.package}/BeanShellScriptTest.java"/>
     <exclude name="${ant.package}/taskdefs/ImportTest.java"/>
@@ -617,12 +665,11 @@
          <include name="junit-noframes.xsl"/>
        </fileset>
     </copy>
-
   </target>
 
   <!--
        ===================================================================
-         Create the Apache Ant jars: ant.jar and optional.jar
+         Create the all of the Apache Ant jars
        ===================================================================
   -->
   <target name="jars"
@@ -659,6 +706,15 @@
       </section>
     </manifest>
 
+    <jar destfile="${build.lib}/${name}-launcher.jar"
+         basedir="${build.classes}">
+      <selector refid="ant.launcher"/>
+      <manifest>
+        <attribute name="Main-Class" value="org.apache.tools.ant.launch.Launcher"/>
+        <attribute name="Class-Path" value="xercesImpl.jar xml-apis.jar"/>
+      </manifest>
+    </jar>
+    
     <jar destfile="${build.lib}/${name}.jar"
          basedir="${build.classes}"
          manifest="${manifest}">
@@ -675,6 +731,7 @@
             <selector refid="needs.jakarta.oro"/>
             <selector refid="needs.jdk1.4+"/>
             <selector refid="needs.javamail"/>
+            <selector refid="ant.launcher"/>
           </or>
         </selector>
       </not>

src/main/org/apache/tools/ant/Main.java

@@ -66,6 +66,8 @@ import java.util.Vector;
 import org.apache.tools.ant.input.DefaultInputHandler;
 import org.apache.tools.ant.input.InputHandler;
 import org.apache.tools.ant.util.JavaEnvUtils;
+import org.apache.tools.ant.launch.AntMain;
+
 
 /**
  * Command line entry point into Ant. This class is entered via the
@@ -79,7 +81,7 @@ import org.apache.tools.ant.util.JavaEnvUtils;
  *
  * @author duncan@x180.com
  */
-public class Main {
+public class Main implements AntMain {
 
     /** The default build file name. */
     public static final String DEFAULT_BUILD_FILENAME = "build.xml";
@@ -175,11 +177,25 @@ public class Main {
      */
     public static void start(String[] args, Properties additionalUserProperties,
                              ClassLoader coreLoader) {
-        Main m = null;
+        Main m = new Main();
+        m.startAnt(args, additionalUserProperties, coreLoader);
+    }
+    
+    /**
+     * Start Ant
+     * @param args command line args
+     * @param additionalUserProperties properties to set beyond those that
+     *        may be specified on the args list
+     * @param coreLoader - not used
+     *
+     * @since Ant 1.6
+     */     
+    public void startAnt(String[] args, Properties additionalUserProperties,
+                         ClassLoader coreLoader) {
 
         try {
             Diagnostics.validateVersion();
-            m = new Main(args);
+            processArgs(args);
         } catch (Throwable exc) {
             handleLogfile();
             printMessage(exc);
@@ -191,17 +207,17 @@ public class Main {
                     e.hasMoreElements();) {
                 String key = (String) e.nextElement();
                 String property = additionalUserProperties.getProperty(key);
-                m.definedProps.put(key, property);
+                definedProps.put(key, property);
             }
         }
 
         // expect the worst
         int exitCode = 1;
         try {
-            m.runBuild(coreLoader);
+            runBuild(coreLoader);
             exitCode = 0;
         } catch (BuildException be) {
-            if (m.err != System.err) {
+            if (err != System.err) {
                 printMessage(be);
             }
         } catch (Throwable exc) {
@@ -248,6 +264,13 @@ public class Main {
         start(args, null, null);
     }
 
+    /**
+     * Constructor used when creating Main for later arg processing
+     * and startup
+     */
+    public Main() {
+    }
+    
     /**
      * Sole constructor, which parses and deals with command line
      * arguments.
@@ -258,6 +281,17 @@ public class Main {
      *                           or is a directory.
      */
     protected Main(String[] args) throws BuildException {
+        processArgs(args);
+    }
+    
+    /**
+     * Process command line arguments
+     *
+     * @param args the command line arguments.
+     *
+     * @since Ant 1.6
+     */
+    private void processArgs(String[] args) {
         String searchForThis = null;
         PrintStream logTo = null;
 
@@ -656,8 +690,8 @@ public class Main {
             try {
                 BuildListener listener =
                     (BuildListener) Class.forName(className).newInstance();
-                if ( project != null ) {
-                    project.setProjectReference( listener );
+                if (project != null) {
+                    project.setProjectReference(listener);
                 }
                 project.addBuildListener(listener);
             } catch (Throwable exc) {
@@ -670,6 +704,8 @@ public class Main {
     /**
      * Creates the InputHandler and adds it to the project.
      *
+     * @param project the project instance.
+     *
      * @exception BuildException if a specified InputHandler
      *                           implementation could not be loaded.
      */
@@ -681,8 +717,8 @@ public class Main {
             try {
                 handler = (InputHandler)
                     (Class.forName(inputHandlerClassname).newInstance());
-                if ( project != null ) {
-                    project.setProjectReference( handler );
+                if (project != null) {
+                    project.setProjectReference(handler);
                 }
             } catch (ClassCastException e) {
                 String msg = "The specified input handler class "
@@ -713,7 +749,8 @@ public class Main {
         BuildLogger logger = null;
         if (loggerClassname != null) {
             try {
-                logger = (BuildLogger) (Class.forName(loggerClassname).newInstance());
+                Class loggerClass = Class.forName(loggerClassname);
+                logger = (BuildLogger) (loggerClass.newInstance());
             } catch (ClassCastException e) {
                 System.err.println("The specified logger class "
                     + loggerClassname
@@ -918,6 +955,8 @@ public class Main {
      * Writes a formatted list of target names to <code>System.out</code>
      * with an optional description.
      *
+     *
+     * @param project the project instance.
      * @param names The names to be printed.
      *              Must not be <code>null</code>.
      * @param descriptions The associated target descriptions.

src/main/org/apache/tools/ant/launch/AntMain.java

@@ -0,0 +1,79 @@
+/*
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2003 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ *    any, must include the following acknowlegement:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowlegement may appear in the software itself,
+ *    if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Ant", and "Apache Software
+ *    Foundation" must not be used to endorse or promote products derived
+ *    from this software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ *    nor may "Apache" appear in their names without prior written
+ *    permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+package org.apache.tools.ant.launch;
+
+import java.util.Properties;
+
+/**
+ * Interface used to bridge to the actual Main class without any
+ * messy reflection
+ *
+ * @author  Conor MacNeill
+ * @since Ant 1.6
+ */
+public interface AntMain {
+    /**
+     * Start Ant.
+     *
+     * @param args command line args
+     * @param additionalUserProperties properties to set beyond those that
+     *        may be specified on the args list
+     * @param coreLoader - not used
+     *
+     * @since Ant 1.6
+     */
+    void startAnt(String[] args, Properties additionalUserProperties, 
+                  ClassLoader coreLoader);
+}
+

src/main/org/apache/tools/ant/launch/Launcher.java

@@ -0,0 +1,168 @@
+/*
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2003 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ *    any, must include the following acknowlegement:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowlegement may appear in the software itself,
+ *    if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Ant", and "Apache Software
+ *    Foundation" must not be used to endorse or promote products derived
+ *    from this software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ *    nor may "Apache" appear in their names without prior written
+ *    permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+package org.apache.tools.ant.launch;
+
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.net.MalformedURLException;
+import java.io.File;
+
+/**
+ *  This is a launcher for Ant.
+ *
+ * @author  Conor MacNeill
+ * @since Ant 1.6
+ */
+public class Launcher {
+    /** The Ant Home property */
+    public static final String ANTHOME_PROPERTY = "ant.home";
+
+    /** The location of a per-user library directory */
+    public static final String USER_LIBDIR = ".ant/lib";
+    
+    /** The startup class that is to be run */
+    public static final String MAIN_CLASS = "org.apache.tools.ant.Main";
+
+    /**
+     *  Entry point for starting command line Ant
+     *
+     * @param  args commandline arguments
+     */
+    public static void main(String[] args) {
+        try {
+            Launcher launcher = new Launcher();
+            launcher.run(args);
+        } catch (Throwable t) {
+            t.printStackTrace();
+        }
+    }
+
+
+    /**
+     * Run the launcher to launch Ant
+     *
+     * @param args the command line arguments
+     *
+     * @exception MalformedURLException if the URLs required for the classloader
+     *            cannot be created.
+     */
+    private void run(String[] args) throws MalformedURLException {
+        String antHomeProperty = System.getProperty(ANTHOME_PROPERTY);
+        File antHome = null;
+
+        URL launchJarURL = Locator.getClassLocationURL(getClass());
+        File jarDir = new File(launchJarURL.getFile()).getParentFile();
+        
+        if (antHomeProperty != null) {
+            antHome = new File(antHomeProperty);
+        }
+        
+        if (antHome == null || !antHome.exists()) {
+            URL antHomeURL = new URL(launchJarURL, "..");
+            antHome = new File(antHomeURL.getFile());
+            System.setProperty(ANTHOME_PROPERTY, antHome.getAbsolutePath());
+        }
+        
+        if (!antHome.exists()) {
+            throw new IllegalStateException("Ant home is set incorrectly or " 
+                + "ant could not be located");
+        }
+        
+        
+        // Now try and find JAVA_HOME
+        File toolsJar = Locator.getToolsJar();
+        
+        URL[] systemJars = Locator.getLocationURLs(jarDir);
+
+        File userLibDir 
+            = new File(System.getProperty("user.home"), USER_LIBDIR);
+        URL[] userJars = Locator.getLocationURLs(userLibDir);
+
+
+        int numJars = userJars.length + systemJars.length;
+        if (toolsJar != null) {
+            numJars++;
+        }
+        URL[] jars = new URL[numJars];
+        System.arraycopy(userJars, 0, jars, 0, userJars.length);
+        System.arraycopy(systemJars, 0, jars, userJars.length, 
+            systemJars.length);
+            
+        if (toolsJar != null) {
+            jars[jars.length - 1] = toolsJar.toURL();
+        }
+
+        
+        // now update the class.path property
+        StringBuffer baseClassPath 
+            = new StringBuffer(System.getProperty("java.class.path"));
+        
+        for (int i = 0; i < jars.length; ++i) {
+            baseClassPath.append(File.pathSeparatorChar);
+            baseClassPath.append(jars[i].getFile());
+        }
+        
+        System.setProperty("java.class.path", baseClassPath.toString());
+
+        URLClassLoader loader = new URLClassLoader(jars);
+        try {
+            Class mainClass = loader.loadClass(MAIN_CLASS);
+            AntMain main = (AntMain) mainClass.newInstance();
+            main.startAnt(args, null, null);
+        } catch (Throwable t) {
+            t.printStackTrace();
+        }
+    }
+}
+

src/main/org/apache/tools/ant/launch/Locator.java

@@ -0,0 +1,226 @@
+/*
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2003 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ *    any, must include the following acknowlegement:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowlegement may appear in the software itself,
+ *    if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Ant", and "Apache Software
+ *    Foundation" must not be used to endorse or promote products derived
+ *    from this software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ *    nor may "Apache" appear in their names without prior written
+ *    permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+package org.apache.tools.ant.launch;
+
+import java.net.MalformedURLException;
+
+import java.net.URL;
+import java.io.File;
+import java.io.FilenameFilter;
+
+/**
+ * The Locator is a utility class which is used to find certain items
+ * in the environment
+ *
+ * @author Conor MacNeill
+ * @since Ant 1.6
+ */
+public class Locator {
+    /**
+     * Get the URL for the given class's load location.
+     *
+     * @param theClass the class whose load URL is desired.
+     * @return a URL which identifies the component from which this class
+     *      was loaded.
+     * @throws MalformedURLException if the class' URL cannot be
+     *      constructed.
+     */
+    public static URL getClassLocationURL(Class theClass)
+         throws MalformedURLException {
+        String className = theClass.getName().replace('.', '/') + ".class";
+        URL classRawURL = theClass.getClassLoader().getResource(className);
+
+        String fileComponent = classRawURL.getFile();
+        if (classRawURL.getProtocol().equals("file")) {
+            // Class comes from a directory of class files rather than
+            // from a jar.
+            int classFileIndex = fileComponent.lastIndexOf(className);
+            if (classFileIndex != -1) {
+                fileComponent = fileComponent.substring(0, classFileIndex);
+            }
+
+            return new URL("file:" + fileComponent);
+        } else if (classRawURL.getProtocol().equals("jar")) {
+            // Class is coming from a jar. The file component of the URL
+            // is actually the URL of the jar file
+            int classSeparatorIndex = fileComponent.lastIndexOf("!");
+            if (classSeparatorIndex != -1) {
+                fileComponent = fileComponent.substring(0, classSeparatorIndex);
+            }
+
+            return new URL(fileComponent);
+        } else {
+            // its running out of something besides a jar.
+            // We just return the Raw URL as a best guess
+            return classRawURL;
+        }
+    }
+
+    /**
+     * Get the URL necessary to load the Sun compiler tools. If the classes
+     * are available to this class, then no additional URL is required and
+     * null is returned. This may be because the classes are explcitly in the
+     * class path or provided by the JVM directly
+     *
+     * @return the tools jar as a File if required, null otherwise
+     */
+    public static File getToolsJar() {
+        // firstly check if the tols jar is alreayd n the classpath
+        boolean toolsJarAvailable = false;
+        
+        try {
+            // just check whether this throws an exception
+            Class.forName("com.sun.tools.javac.Main");
+            toolsJarAvailable = true;
+        } catch (Exception e) {
+            try {
+                Class.forName("sun.tools.javac.Main");
+                toolsJarAvailable = true;
+            } catch (Exception e2) {
+                // ignore
+            }
+        }
+        
+        if (toolsJarAvailable) {
+            return null;
+        }
+         
+        // couldn't find compiler - try to find tools.jar
+        // based on java.home setting
+        String javaHome = System.getProperty("java.home");
+        if (javaHome.endsWith("jre")) {
+            javaHome = javaHome.substring(0, javaHome.length() - 4);
+        }
+        File toolsJar = new File(javaHome + "/lib/tools.jar");
+        if (!toolsJar.exists()) {
+            System.out.println("Unable to locate tools.jar. "
+                 + "Expected to find it in " + toolsJar.getPath());
+            return null;
+        }
+        return toolsJar;
+    }
+    
+    /**
+     * Get an array or URLs representing all of the jar files in the
+     * given location. If the location is a file, it is returned as the only
+     * element of the array. If the location is a directory, it is scanned for
+     * jar files
+     *
+     * @param location the location to scan for Jars
+     *
+     * @return an array of URLs for all jars in the given location.
+     *
+     * @exception MalformedURLException if the URLs for the jars cannot be 
+     *            formed
+     */
+    public static URL[] getLocationURLs(File location)
+         throws MalformedURLException {
+        return getLocationURLs(location, new String[]{".jar"});
+    }
+
+    /**
+     * Get an array or URLs representing all of the files of a given set of 
+     * extensions in the given location. If the location is a file, it is 
+     * returned as the only element of the array. If the location is a 
+     * directory, it is scanned for matching files
+     *
+     * @param location the location to scan for files
+     * @param extensions an array of extension that are to match in the 
+     *        directory search
+     *
+     * @return an array of URLs of matching files
+     * @exception MalformedURLException if the URLs for the files cannot be 
+     *            formed
+     */
+    public static URL[] getLocationURLs(File location, 
+                                        final String[] extensions)
+         throws MalformedURLException {
+        URL[] urls = new URL[0];
+
+        if (!location.exists()) {
+            return urls;
+        }
+
+        if (!location.isDirectory()) {
+            urls = new URL[1];
+            String path = location.getPath();
+            for (int i = 0; i < extensions.length; ++i) {
+                if (path.endsWith(extensions[i])) {
+                    urls[0] = location.toURL();
+                    break;
+                }
+            }
+            return urls;
+        }
+
+        File[] matches = location.listFiles(
+            new FilenameFilter() {
+                public boolean accept(File dir, String name) {
+                    for (int i = 0; i < extensions.length; ++i) {
+                        if (name.endsWith(extensions[i])) {
+                            return true;
+                        }
+                    }
+                    return false;
+                }
+            });
+            
+        urls = new URL[matches.length];
+        for (int i = 0; i < matches.length; ++i) {
+            urls[i] = matches[i].toURL();
+        }
+        return urls;
+    }
+}
+