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diff --git a/sca-java-1.x/tags/1.6.1-TUSCANY-3909/host-embedded/src/main/java/org/apache/tuscany/sca/host/embedded/impl/HotUpdatableSCADomain.java b/sca-java-1.x/tags/1.6.1-TUSCANY-3909/host-embedded/src/main/java/org/apache/tuscany/sca/host/embedded/impl/HotUpdatableSCADomain.java
new file mode 100644
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+++ b/sca-java-1.x/tags/1.6.1-TUSCANY-3909/host-embedded/src/main/java/org/apache/tuscany/sca/host/embedded/impl/HotUpdatableSCADomain.java
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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.host.embedded.impl;
+
+import java.io.File;
+import java.io.FilenameFilter;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.MalformedURLException;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.logging.Logger;
+
+import org.apache.tuscany.sca.assembly.Composite;
+import org.apache.tuscany.sca.assembly.builder.CompositeBuilderException;
+import org.apache.tuscany.sca.contribution.Contribution;
+import org.apache.tuscany.sca.contribution.service.ContributionService;
+import org.apache.tuscany.sca.contribution.service.util.FileHelper;
+import org.apache.tuscany.sca.core.assembly.ActivationException;
+import org.apache.tuscany.sca.host.embedded.SCADomain;
+import org.apache.tuscany.sca.host.embedded.management.ComponentManager;
+import org.osoa.sca.CallableReference;
+import org.osoa.sca.ServiceReference;
+import org.osoa.sca.ServiceRuntimeException;
+
+/**
+ * An SCADomain that starts a Tuscany runtime supporting multiple
+ * SCA contribution jars. All contribution jars found in a repository
+ * directory will be contributed to the SCA domain. Any changes to the
+ * contributions in that repository will be automatically detected and
+ * the SCADomain updated accordingly.
+ * 
+ *  TODO: find how to properly add/remove contributions and start/activate the SCADomain
+ *  TODO: support contributions that are folders as well as jar's
+ *  TODO: needs to restart the entire SCADomain when a contribution changes
+ *        as the domain classpath includes all the contribution jar's, would
+ *        be nice to find a way to avoid this
+ *  TODO: hot update requires copying contribution jars to a temp location
+ *        to avoid the classpath lock preventing updating the contribution
+ *        jars, would be nice to find a way to avoid that
+ *
+ * @version $Rev$ $Date$
+ */
+public class HotUpdatableSCADomain extends SCADomain {
+    private static final Logger logger = Logger.getLogger(HotUpdatableSCADomain.class.getName());
+    protected String domainURI;
+    protected File contributionRepository;
+    
+    protected EmbeddedSCADomain scaDomain;
+
+    protected boolean hotUpdateActive;
+    protected Thread hotUpdateThread;
+    protected int hotUpdateInterval; //  milliseconds, 0 = hotupdate disabled
+
+    protected HashMap<URL, Long> existingContributions; // value is last modified time
+    protected ClassLoader originalCCL;
+
+    protected static final String REPOSITORY_FOLDER = "sca-contributions";
+    
+    public HotUpdatableSCADomain(String domainURI, File contributionRepository, int hotupdateInterval) {
+        this.domainURI = domainURI;
+        this.contributionRepository = contributionRepository;
+        this.hotUpdateInterval = hotupdateInterval;
+        this.originalCCL = Thread.currentThread().getContextClassLoader();
+        start();
+    }
+    
+    protected void start() {
+        try {
+            initEmbeddedSCADomain();
+            activateHotUpdate();
+            for (URL url : existingContributions.keySet()) {
+                File f = new File(url.toURI());
+                logger.info("added contribution: " + f.getName());
+            }
+        } catch (ActivationException e) {
+            throw new ServiceRuntimeException(e);
+        } catch (URISyntaxException e) {
+            throw new ServiceRuntimeException(e);
+        }
+    }
+    
+    @Override
+    public void close() {
+        try {
+            hotUpdateActive = false;
+            scaDomain.stop();
+        } catch (ActivationException e) {
+            throw new ServiceRuntimeException(e);
+        }
+        Thread.currentThread().setContextClassLoader(originalCCL);
+        super.close();
+    }
+
+
+    protected SCADomain initEmbeddedSCADomain() throws ActivationException {
+
+        URL[] contributionJars = getContributionJarURLs(contributionRepository);
+
+        this.existingContributions = getLastModified(contributionJars);
+
+        if (hotUpdateInterval > 0) {
+            contributionJars = copyContributionsToTemp(contributionJars);
+        }
+
+        // Using the CCL as the parent exposes Tuscany to the contributions, want to do this? 
+        URLClassLoader cl = new URLClassLoader(contributionJars, originalCCL);
+        Thread.currentThread().setContextClassLoader(cl);
+
+        scaDomain = new EmbeddedSCADomain(cl, domainURI);
+
+        scaDomain.start();
+
+        initContributions(scaDomain, cl, contributionJars);
+        
+        return scaDomain;
+    }
+
+    protected URL[] getContributionJarURLs(File repositoryDir) {
+
+        String[] jars = repositoryDir.list(new FilenameFilter() {
+            public boolean accept(File dir, String name) {
+                return name.endsWith(".jar");
+            }});
+
+        List<URL> contributionJars = new ArrayList<URL>();
+        if (jars != null) {
+            for (String jar : jars) {
+                try {
+                    contributionJars.add(new File(repositoryDir, jar).toURL());
+                } catch (MalformedURLException e) {
+                    throw new RuntimeException(e);
+                }
+            }
+        }
+
+        return contributionJars.toArray(new URL[contributionJars.size()]);
+    }
+
+    /**
+     * TODO: No idea what the 'correct' way to add/contribute and activate/start things to an scaDomain is
+     *       but this seems to work. Doesn't seem to start <service>s or <reference>s which are outside of
+     *       a <component> so something is missing/wrong. Also this doesn't seem to be picking up composites
+     *       located in META-INF/deployables or specified in the sca-deployables.xml. Maybe the EmbeddedSCADomain
+     *       and ContributionService APIs should make all this easier?
+     */
+    protected void initContributions(EmbeddedSCADomain scaDomain,  ClassLoader cl, URL[] contributionJars) {
+    	Contribution contribution = null;
+        ContributionService contributionService = scaDomain.getContributionService();
+        for (URL jar : contributionJars) {
+            InputStream is = null;
+            try {
+                is = jar.openStream();
+                contribution = contributionService.contribute(jar.toString(), jar, is);
+            } catch (Exception e) {
+                System.err.println("exception adding contribution: " + jar);
+                e.printStackTrace();
+            }
+            if (is != null) {
+                try {
+                    is.close();
+                } catch (IOException e) {
+                    // ignore
+                }
+            }
+        }
+        
+        if (contribution != null ) {
+            try {
+
+                for (Composite composite : contribution.getDeployables()) {
+                    scaDomain.getDomainComposite().getIncludes().add(composite);
+                    scaDomain.getCompositeBuilder().build(composite);
+                    scaDomain.getCompositeActivator().activate(composite);
+                }
+
+                for (Composite composite : contribution.getDeployables()) {
+                     scaDomain.getCompositeActivator().start(composite);
+                }
+
+            } catch (ActivationException e) {
+                throw new RuntimeException(e);
+            } catch (CompositeBuilderException e) {
+                throw new RuntimeException(e);
+            }        	
+        }
+        
+    }
+
+    /**
+     * Copies Files to a temp location returning the URLs of the new temp files.
+     * For hot update to work need to be able to delete/update the contribution jar's
+     * but as they're in the classpath the URLClassLoader has an open lock on the jar's
+     * so you can't update them. This solution copies each contribution to a temp
+     * location for use on the classpath, nicer would be a ClassLoder impl that doesn't
+     * lock the jar's.
+     */
+    protected URL[] copyContributionsToTemp(URL[] contributionJars) {
+        try {
+
+            URL[] newURLs = new URL[contributionJars.length];
+            File tempDir = new File(System.getProperty("java.io.tmpdir"));
+            for (int i=0; i<contributionJars.length; i++) {
+                File fin = new File(contributionJars[i].toURI());
+                File fout = File.createTempFile("tuscany", fin.getName(), tempDir);
+                fout.deleteOnExit();
+                FileHelper.copyFile(fin, fout);
+                fout.setLastModified(System.currentTimeMillis());
+                newURLs[i] = fout.toURL();
+            }
+            return newURLs;
+
+        } catch (IOException e) {
+            throw new RuntimeException(e);            
+        } catch (URISyntaxException e) {
+            throw new RuntimeException(e);            
+        }
+    }
+
+    /**
+     * Returns the last modified times of the files pointed to by the URLs  
+     */
+    protected HashMap<URL, Long> getLastModified(URL[] contrabutions) {
+        try {
+
+            HashMap<URL, Long> contributionLastUpdates = new HashMap<URL, Long>();
+            for (URL url: contrabutions) {
+                File f = new File(url.toURI());
+                contributionLastUpdates.put(url, new Long(f.lastModified()));
+            }
+            return contributionLastUpdates;
+
+        } catch (URISyntaxException e) {
+            throw new RuntimeException(e);
+        }
+    }
+    
+    protected void activateHotUpdate() {
+        if (hotUpdateInterval == 0) {
+            return; // hotUpdateInterval of 0 disables hotupdate
+        }
+
+        Runnable runable = new Runnable() {
+            public void run() {
+                logger.info("Tuscany contribution hotupdate running");
+                while (hotUpdateActive) {
+                    try {
+                        Thread.sleep(hotUpdateInterval);
+                    } catch (InterruptedException e) {
+                    }
+                    if (hotUpdateActive) {
+                        checkForUpdates();
+                    }
+                }
+                logger.info("Tuscany contribution hotupdate stopped");
+            }
+        };
+        hotUpdateThread = new Thread(runable, "TuscanyHotUpdate");
+        hotUpdateActive = true;
+        hotUpdateThread.start();
+    }
+
+
+    /**
+     * Checks if any of the contributions have been updated and if so restarts the SCADomain
+     * TODO: Ideally just the altered contribution would be restarted but thats not possible
+     *       as the ClassLoader used by the SCADomain includes the old contribution so need
+     *       to restart the entire domain to use a new ClassLoader. Should there be separate 
+     *       ClassLoader per contribution? But then have all the issues with sharing classes
+     *       across contributions.
+     */
+    protected void checkForUpdates() {
+        URL[] currentContributions = getContributionJarURLs(contributionRepository);
+        
+        if (areContributionsAltered(currentContributions)) {
+            try {
+                scaDomain.stop();
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+            try {
+                initEmbeddedSCADomain();
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+    protected boolean areContributionsAltered(URL[] currentContrabutions) {
+        try {
+            
+            List addedContributions = getAddedContributions(currentContrabutions);
+            List removedContributions = getRemovedContributions(currentContrabutions);
+            List updatedContributions = getUpdatedContributions(currentContrabutions);
+            
+            return (addedContributions.size() > 0 || removedContributions.size() > 0 || updatedContributions.size() > 0);
+
+        } catch (URISyntaxException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    protected List<URL> getUpdatedContributions(URL[] currentContrabutions) throws URISyntaxException {
+        List<URL> urls = new ArrayList<URL>();
+        for (URL url : currentContrabutions) {
+            if (existingContributions.containsKey(url)) {
+                File curentFile = new File(url.toURI());
+                if (curentFile.lastModified() != existingContributions.get(url)) {
+                    urls.add(url);
+                    logger.info("updated contribution: " + curentFile.getName());
+                }
+            }
+        }
+        return urls;
+    }
+
+    protected List getRemovedContributions(URL[] currentContrabutions) throws URISyntaxException {
+        List<URL> currentUrls = Arrays.asList(currentContrabutions);
+        List<URL> urls = new ArrayList<URL>();
+        for (URL url : existingContributions.keySet()) {
+            if (!currentUrls.contains(url)) {
+                urls.add(url);
+            }
+        }
+        for (URL url : urls) {
+            logger.info("removed contributions: " + new File(url.toURI()).getName());
+        }
+        return urls;
+    }
+
+    protected List getAddedContributions(URL[] currentContrabutions) throws URISyntaxException {
+        List<URL> urls = new ArrayList<URL>();
+        for (URL url : currentContrabutions) {
+            if (!existingContributions.containsKey(url)) {
+                urls.add(url);
+                logger.info("added contribution: " + new File(url.toURI()).getName());
+            }
+        }
+        return urls;
+    }
+
+    @Override
+    public <B, R extends CallableReference<B>> R cast(B target) throws IllegalArgumentException {
+        throw new UnsupportedOperationException("not implemented");
+    }
+
+    @Override
+    public <B> B getService(Class<B> businessInterface, String serviceName) {
+        return scaDomain.getService(businessInterface, serviceName);
+    }
+
+    @Override
+    public <B> ServiceReference<B> getServiceReference(Class<B> businessInterface, String referenceName) {
+        return scaDomain.getServiceReference(businessInterface, referenceName);
+    }
+
+    @Override
+    public String getURI() {
+        return domainURI;
+    }
+
+    @Override
+    public ComponentManager getComponentManager(){
+        return  scaDomain.getComponentManager();
+    }
+
+}