use serviceloader to create/start server

define 'contract' between bootstrap and server (AditoServerFactory) to create/start server.
Because switch of classloader needed, reflection can not be replace completly. But do not use/load classes
from different module.

fixes adito/#15

Author: toepi

adito-boot/src/main/java/com/adito/boot/AditoServerFactory.java

@@ -0,0 +1,10 @@
+package com.adito.boot;
+
+/**
+ *
+ * @author toepi <toepi@users.noreply.github.com>
+ */
+public interface AditoServerFactory {
+
+    void createServer(ClassLoader bootLoader, String[] args);
+}

adito-boot/src/main/java/com/adito/boot/Bootstrap.java

@@ -1,5 +1,4 @@
-
-				/*
+/*
  *  Adito
  *
  *  Copyright (C) 2003-2006 3SP LTD. All Rights Reserved
@@ -17,7 +16,6 @@
  *  License along with this program; if not, write to the Free Software
  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
-			
 package com.adito.boot;
 
 import java.io.File;
@@ -38,8 +36,8 @@
 
 /**
  * ALL CHANGED - REWRITE
- * 
- * 
+ *
+ *
  * Bootstrap an Adito server implementation. The first argument passed to
  * {@link #main(String[])} should be the class name of the server
  * implementation.
@@ -48,33 +46,56 @@
  * <code>setBootLoader(ClassLoader bootLoader)</code> and
  * <code>main(String[] args)</code>.
  * <p>
- * A classpath.properties file in the 
+ * A classpath.properties file in the
  * <p>
  * The server will be loaded using a new class loader that scans the
  * <b>serverlib</b> directory for any jars specific to this implementation. The
  * parent of this classloader is the <i>Boot Loader</i>
- * 
- * The <i>Boot Loader</i> is the class loader that loads all of the boot
- * classes and anything in lib.
+ *
+ * The <i>Boot Loader</i> is the class loader that loads all of the boot classes
+ * and anything in lib.
  * <p>
- * The server implementation should use the <i>Boot Loader</i> as the parent
- * for the Adito web application. This hides the server implementation
- * from the Adito core and any of its extensions.
- * 
+ * The server implementation should use the <i>Boot Loader</i> as the parent for
+ * the Adito web application. This hides the server implementation from the
+ * Adito core and any of its extensions.
+ *
  */
 public class Bootstrap {
 
-    // Private instance variables
+    /**
+     * Entry point. First argument should be the server implementation class
+     * name. Remaining arguments are passed to create server.
+     *
+     * @param args arguments
+     * @throws Exception
+     */
+    public static void main(final String[] args) throws Exception {
+        final List<String> argList = new ArrayList<String>(Arrays.asList(args));
+        if (argList.size() > 1 && argList.get(0).equals("--serverImpl")) {
+            argList.remove(0);
+            argList.remove(0);
+        }
+
+        // Look for --conf argument and add that to that classpath
+        File conf = new File("conf");
+        for (String arg : argList) {
+            if (arg.startsWith("--conf=")) {
+                conf = new File(arg.substring(7));
+            }
+        }
 
+        // Create the bootstrap, configure it and start the server
+        new Bootstrap().withClassLoaders(conf)
+                .start(argList.toArray(new String[argList.size()]));
+    }
     private ClassLoader serverLoader;
-    private ClassLoader bootLoader;   
+    private ClassLoader bootLoader;
     private File conf;
     private Properties classpath;
 
     /**
      * Start the server implementation.
-     * 
-     * @param serverImplClassName server implementation
+     *
      * @param args arguments
      * @throws ClassNotFoundException
      * @throws SecurityException
@@ -83,21 +104,29 @@ public class Bootstrap {
      * @throws IllegalAccessException
      * @throws InvocationTargetException
      */
-    public void start(String serverImplClassName, String[] args) throws ClassNotFoundException, SecurityException,
-                    NoSuchMethodException, IllegalArgumentException, IllegalAccessException, InvocationTargetException {
-        Class<?> serverClass = Class.forName(serverImplClassName, true, serverLoader);
-        Method setBootLoaderMethod = serverClass.getMethod("setBootLoader", new Class[] { ClassLoader.class });
-        setBootLoaderMethod.invoke(null, new Object[] { bootLoader });
-        Method mainMethod = serverClass.getMethod("main", new Class[] { String[].class });
-        mainMethod.invoke(null, new Object[] { args });
+    public void start(final String[] args) throws ClassNotFoundException, NoSuchMethodException, IllegalArgumentException,
+            InvocationTargetException, IllegalAccessException {
+        
+        if (serverLoader == null || bootLoader == null) {
+            throw new IllegalStateException("Needed classloaders not configured!");
+        }
+        
+        Thread.currentThread().setContextClassLoader(serverLoader);
+        Class.forName(ServerStarter.class.getName(), true, serverLoader)
+                .getMethod("start", ClassLoader.class, String[].class).invoke(null, bootLoader, args);
+    }
+    
+    public Bootstrap withClassLoaders(final File conf) throws IOException, URISyntaxException {
+        configureClassLoaders(conf);
+        return this;
     }
 
     /**
      * Configure the class loaders.
-     * 
+     *
      * @param conf conf directory
      * @throws IOException
-     * @throws URISyntaxException 
+     * @throws URISyntaxException
      */
     public void configureClassLoaders(File conf) throws IOException, URISyntaxException {
         this.conf = conf;
@@ -114,29 +143,29 @@ public void configureClassLoaders(File conf) throws IOException, URISyntaxExcept
         serverLoader = new URLClassLoader(serverLibs.toArray(new URL[serverLibs.size()]), bootLoader);
 
     }
-    
+
     private void addJarPaths(String propertyName, List<URL> libs) throws MalformedURLException, IOException {
         String paths = classpath.getProperty(propertyName);
-        if(paths != null) {
+        if (paths != null) {
             StringTokenizer t = new StringTokenizer(paths, ",");
-            while(t.hasMoreTokens()) {
+            while (t.hasMoreTokens()) {
                 addDirLibs(new File(t.nextToken()), libs);
             }
         }
     }
-    
+
     private void addDirPaths(String propertyName, List<URL> libs) throws MalformedURLException, IOException {
         String paths = classpath.getProperty(propertyName);
-        if(paths != null) {
+        if (paths != null) {
             StringTokenizer t = new StringTokenizer(paths, ",");
-            while(t.hasMoreTokens()) {
+            while (t.hasMoreTokens()) {
                 addDir(new File(t.nextToken()), libs);
             }
         }
     }
 
     private void addDirLibs(File dir, List<URL> libs) throws MalformedURLException, IOException {
-        if(!dir.exists() || !dir.isDirectory()) {
+        if (!dir.exists() || !dir.isDirectory()) {
             return;
         }
         for (File jar : dir.listFiles(new FileFilter() {
@@ -150,59 +179,25 @@ public boolean accept(File pathname) {
 
     private URL[] debugClasspath(String string, URL[] urls) throws URISyntaxException {
         System.out.println("Classloader " + string);
-        for(int i = 0 ; i < urls.length ; i++) {
+        for (int i = 0; i < urls.length; i++) {
             System.out.println(new File(urls[i].toURI()).getAbsolutePath());
         }
         return urls;
     }
 
     private void addDir(File dir, List<URL> libs) throws MalformedURLException, IOException {
-        if(dir.exists() || !dir.isDirectory()) {
+        if (dir.exists() || !dir.isDirectory()) {
             libs.add(dir.getCanonicalFile().toURI().toURL());
-        }        
+        }
     }
-    
+
     private void loadClasspathConfiguration() throws IOException {
         FileInputStream fin = new FileInputStream(new File(conf, "classpath.properties"));
         try {
             classpath = new Properties();
             classpath.load(fin);
+        } finally {
+            fin.close();
         }
-        finally {
-            if(fin != null) {
-                fin.close();
-            }
-        }
-    }
-
-    /**
-     * Entry point. First argument should be the server implementation class
-     * name. Remaining arguments are passed to create server.
-     * 
-     * @param args arguments
-     * @throws Exception
-     */
-    public static void main(String[] args) throws Exception {
-        List<String> argList = new ArrayList<String>(Arrays.asList(args));
-        String serverImplClassName = "com.adito.server.Main";
-        if(argList.size() > 1 && argList.get(0).equals("--serverImpl")) {
-            argList.remove(0);
-            serverImplClassName = argList.get(0);
-            argList.remove(0);
-        }
-        args = argList.toArray(new String[argList.size()]);
-        
-        // Look for --conf argument and add that to that classpath
-        File conf = new File("conf");
-        for(String arg : argList) {
-            if(arg.startsWith("--conf=")) {
-                conf = new File(arg.substring(7));
-            }
-        }
-
-        // Create the bootstrap, configure it and start the server
-        Bootstrap bootstrap = new Bootstrap();
-        bootstrap.configureClassLoaders(conf);
-        bootstrap.start(serverImplClassName, args);
     }
 }

adito-boot/src/main/java/com/adito/boot/ServerStarter.java

@@ -0,0 +1,26 @@
+package com.adito.boot;
+
+import java.util.Iterator;
+import java.util.ServiceLoader;
+
+/**
+ *
+ * @author toepi <toepi@users.noreply.github.com>
+ */
+public final class ServerStarter {
+
+    public static void start(final ClassLoader bootLoader, final String[] args) {
+        if (bootLoader == null) {
+            throw new IllegalStateException("Bootloader must be not null!");
+        }
+        final Iterator<AditoServerFactory> serverFactoryIterator = ServiceLoader.load(AditoServerFactory.class).iterator();
+        if (serverFactoryIterator.hasNext()) {
+            serverFactoryIterator.next().createServer(bootLoader, args);
+        } else {
+            throw new IllegalStateException("No AditoServerFactory found! Check your classpath.");
+        }
+    }
+
+    private ServerStarter() {
+    }
+}