2 Replies Latest reply on Apr 10, 2007 3:31 PM by gmoraes

    Hot deploy error

    luizruiz

      Hi,

      Trying to use hot deploy to reload MyClass.components.xml I had an ClassNotFoundException. The installComponentFromXmlElement method of Initialization try to load the class with Reflections.classForName(className), wich use the current thread classloader, the WebAppClassloader, not hotDeployClassloader. Fix with the code above:

       Class<?> clazz = null;
       try
       {
       if (hotDeployClassLoader != null) {
       clazz = hotDeployClassLoader.loadClass(className)
       }
       clazz = Reflections.classForName(className);
       }
      
      


      Is this the right way?

        • 1. Re: Hot deploy error
          luizruiz

          BTW,

          JBoss Seam 1.2.1
          Tomcat 5.5.20
          Java 1.6

          • 2. Re: Hot deploy error
            gmoraes

            I was trying to use hotdeploy in tomcat 5.5 with components registered in /WEB-INF/dev/META-INF/components.xml and got some problems so I made some little corrections in Initialization.java.
            Please verify the changes e test if I created some type of problem.

            /*
             * JBoss, Home of Professional Open Source
             *
             * Distributable under LGPL license. See terms of license at gnu.org.
             */
            package org.jboss.seam.init;
            
            import java.io.File;
            import java.io.IOException;
            import java.io.InputStream;
            import java.net.MalformedURLException;
            import java.net.URL;
            import java.net.URLClassLoader;
            import java.util.ArrayList;
            import java.util.Enumeration;
            import java.util.HashMap;
            import java.util.HashSet;
            import java.util.List;
            import java.util.Map;
            import java.util.Properties;
            import java.util.Set;
            import java.util.StringTokenizer;
            import java.util.TreeSet;
            
            import javax.servlet.ServletContext;
            import javax.servlet.http.HttpSession;
            
            import org.dom4j.Attribute;
            import org.dom4j.DocumentException;
            import org.dom4j.Element;
            import org.jboss.seam.Component;
            import org.jboss.seam.ScopeType;
            import org.jboss.seam.Seam;
            import org.jboss.seam.annotations.Install;
            import org.jboss.seam.annotations.Name;
            import org.jboss.seam.annotations.Namespace;
            import org.jboss.seam.annotations.Role;
            import org.jboss.seam.annotations.Roles;
            import org.jboss.seam.contexts.Context;
            import org.jboss.seam.contexts.Contexts;
            import org.jboss.seam.contexts.Lifecycle;
            import org.jboss.seam.core.Expressions;
            import org.jboss.seam.core.Init;
            import org.jboss.seam.core.Jbpm;
            import org.jboss.seam.core.PojoCache;
            import org.jboss.seam.deployment.ComponentScanner;
            import org.jboss.seam.deployment.NamespaceScanner;
            import org.jboss.seam.log.LogProvider;
            import org.jboss.seam.log.Logging;
            import org.jboss.seam.util.Conversions;
            import org.jboss.seam.util.Naming;
            import org.jboss.seam.util.Reflections;
            import org.jboss.seam.util.Resources;
            import org.jboss.seam.util.Strings;
            import org.jboss.seam.util.XML;
            
            /**
             * @author Gavin King
             * @author <a href="mailto:theute@jboss.org">Thomas Heute</a>
             * @version $Revision: 1.166 $
             */
            public class Initialization
            {
             public static final String COMPONENT_SUFFIX = ".component";
             private static final LogProvider log = Logging.getLogProvider(Initialization.class);
            
             private ServletContext servletContext;
             private Map<String, Conversions.PropertyValue> properties = new HashMap<String, Conversions.PropertyValue>();
             private Map<String, Set<ComponentDescriptor>> componentDescriptors = new HashMap<String, Set<ComponentDescriptor>>();
             private List<FactoryDescriptor> factoryDescriptors = new ArrayList<FactoryDescriptor>();
             private Set<Class> installedComponentClasses = new HashSet<Class>();
             private Set<String> importedPackages = new HashSet<String>();
             private Map<String, NamespaceDescriptor> namespaceMap = new HashMap<String, NamespaceDescriptor>();
             private final Map<String, EventListenerDescriptor> eventListenerDescriptors = new HashMap<String, EventListenerDescriptor>();
            
             private File[] hotDeployPaths;
             private ClassLoader hotDeployClassLoader;
            
             public Initialization(ServletContext servletContext)
             {
             this.servletContext = servletContext;
             }
            
             public Initialization create()
             {
             addNamespaces();
             initComponentsFromXmlDocument("/WEB-INF/components.xml");
             initComponentsFromXmlDocument("/WEB-INF/events.xml"); //deprecated
             initComponentsFromXmlDocuments();
             initPropertiesFromServletContext();
             initPropertiesFromResource();
             initJndiProperties();
             return this;
             }
            
             private void initComponentsFromXmlDocuments()
             {
             ClassLoader cl = Thread.currentThread().getContextClassLoader();
             if (hotDeployClassLoader != null) {
             // Must create a new ClassLoader without parent resources to prevent
             // error of duplicate component registration
             URL[] urls = ((URLClassLoader)hotDeployClassLoader).getURLs();
             cl = new URLClassLoader(urls);
             }
             Enumeration<URL> resources;
             try
             {
             resources = cl.getResources("META-INF/components.xml");
             }
             catch (IOException ioe)
             {
             throw new RuntimeException("error scanning META-INF/components.xml files", ioe);
             }
            
             Properties replacements = getReplacements();
             while (resources.hasMoreElements())
             {
             URL url = resources.nextElement();
             try
             {
             log.info("reading " + url);
             installComponentsFromXmlElements( XML.getRootElement( url.openStream() ), replacements );
             }
             catch (Exception e)
             {
             throw new RuntimeException("error while reading " + url, e);
             }
             }
            
             }
            
             private void initComponentsFromXmlDocument(String resource)
             {
             InputStream stream = Resources.getResourceAsStream(resource, servletContext);
             if (stream != null)
             {
             log.info("reading " + resource);
             try
             {
             installComponentsFromXmlElements( XML.getRootElement(stream), getReplacements() );
             }
             catch (Exception e)
             {
             throw new RuntimeException("error while reading /WEB-INF/components.xml", e);
             }
             }
             }
            
             private Properties getReplacements()
             {
             try
             {
             Properties replacements = new Properties();
             InputStream replaceStream = Resources.getResourceAsStream("components.properties");
             if (replaceStream != null) replacements.load(replaceStream);
             return replacements;
             }
             catch (IOException ioe)
             {
             throw new RuntimeException("error reading components.properties", ioe);
             }
             }
            
             @SuppressWarnings("unchecked")
             private void installComponentsFromXmlElements(Element rootElement, Properties replacements)
             throws DocumentException, ClassNotFoundException
             {
             List<Element> importElements = rootElement.elements("import-java-package");
             for (Element importElement : importElements)
             {
             String pkgName = importElement.getTextTrim();
             importedPackages.add(pkgName);
             addNamespace(Package.getPackage(pkgName));
             }
            
             List<Element> componentElements = rootElement.elements("component");
             for (Element component : componentElements)
             {
             installComponentFromXmlElement(component, component.attributeValue("name"), component
             .attributeValue("class"), replacements);
             }
            
             List<Element> factoryElements = rootElement.elements("factory");
             for (Element factory : factoryElements)
             {
             installFactoryFromXmlElement(factory);
             }
            
             List<Element> elements = rootElement.elements("event");
             for (Element event: elements)
             {
             installEventListenerFromXmlElement(event);
             }
            
             for (Element elem : (List<Element>) rootElement.elements())
             {
             String ns = elem.getNamespace().getURI();
             NamespaceDescriptor nsInfo = namespaceMap.get(ns);
             if (nsInfo != null)
             {
             String name = elem.attributeValue("name");
             String elemName = toCamelCase( elem.getName(), true );
            
             String className = nsInfo.getPackage().getName() + '.' + elemName;
             try
             {
             //get the class implied by the namespaced XML element name
             Class<Object> clazz = Reflections.classForName(className);
             Name nameAnnotation = clazz.getAnnotation(Name.class);
            
             //if the name attribute is not explicitly specified in the XML,
             //imply the name from the @Name annotation on the class implied
             //by the XML element name
             if (name == null && nameAnnotation!=null)
             {
             name = nameAnnotation.value();
             }
            
             //if this class already has the @Name annotation, the XML element
             //is just adding configuration to the existing component, don't
             //add another ComponentDescriptor (this is super-important to
             //allow overriding!)
             if ( nameAnnotation!=null && nameAnnotation.value().equals(name) )
             {
             Install install = clazz.getAnnotation(Install.class);
             if ( install == null || install.value() )
             {
             className = null;
             }
             }
             }
             catch (ClassNotFoundException cnfe)
             {
             //there is no class implied by the XML element name so the
             //component must be defined some other way, assume that we are
             //just adding configuration, don't add a ComponentDescriptor
             className = null;
             }
            
             //finally, if we could not get the name from the XML name attribute,
             //or from an @Name annotation on the class, imply it
             if (name == null)
             {
             String prefix = nsInfo.getNamespace().prefix();
             name = Strings.isEmpty(prefix) ?
             elemName : prefix + '.' + elemName;
             }
            
             installComponentFromXmlElement(elem, name, className, replacements);
             }
             }
             }
            
             @SuppressWarnings("unchecked")
             private void installEventListenerFromXmlElement(Element event)
             {
             String type = event.attributeValue("type");
             if (type==null)
             {
             throw new IllegalArgumentException("must specify type for <event/> declaration");
             }
             EventListenerDescriptor eventListener = eventListenerDescriptors.get(type);
             if (eventListener==null)
             {
             eventListener = new EventListenerDescriptor(type);
             eventListenerDescriptors.put(type, eventListener);
             }
            
             List<Element> actions = event.elements("action");
             for (Element action: actions)
             {
             String actionExpression = action.attributeValue("expression");
             if (actionExpression==null)
             {
             throw new IllegalArgumentException("must specify expression for <action/> declaration");
             }
             eventListener.getListenerMethodBindings().add(actionExpression);
             }
             }
            
             private void installFactoryFromXmlElement(Element factory)
             {
             String scopeName = factory.attributeValue("scope");
             String name = factory.attributeValue("name");
             if (name == null)
             {
             throw new IllegalArgumentException("must specify name in <factory/> declaration");
             }
             String method = factory.attributeValue("method");
             String value = factory.attributeValue("value");
             if (method == null && value == null)
             {
             throw new IllegalArgumentException(
             "must specify either method or value in <factory/> declaration for variable: "
             + name);
             }
             ScopeType scope = scopeName == null ? ScopeType.UNSPECIFIED : ScopeType.valueOf(scopeName
             .toUpperCase());
             boolean autoCreate = "true".equals(factory.attributeValue("auto-create"));
             factoryDescriptors.add(new FactoryDescriptor(name, scope, method, value, autoCreate));
             }
            
             private String replace(String value, Properties replacements)
             {
             if (value.startsWith("@"))
             {
             value = replacements.getProperty(value.substring(1, value.length() - 1));
             }
             return value;
             }
            
             @SuppressWarnings("unchecked")
             private void installComponentFromXmlElement(Element component, String name, String className,
             Properties replacements) throws ClassNotFoundException
             {
             String installText = component.attributeValue("installed");
             boolean installed = false;
             if (installText == null || "true".equals(replace(installText, replacements)))
             {
             installed = true;
             }
            
             String scopeName = component.attributeValue("scope");
             String jndiName = component.attributeValue("jndi-name");
             String precedenceString = component.attributeValue("precedence");
             int precedence = precedenceString==null ? Install.APPLICATION : Integer.valueOf(precedenceString);
             ScopeType scope = scopeName == null ? null : ScopeType.valueOf(scopeName.toUpperCase());
             boolean autoCreate = "true".equals(component.attributeValue("auto-create"));
             if (className != null)
             {
             Class<?> clazz = null;
             try
             {
             if (hotDeployClassLoader != null) {
             clazz = hotDeployClassLoader.loadClass(className);
             } else {
             clazz = Reflections.classForName(className);
             }
             }
             catch (ClassNotFoundException cnfe)
             {
             for (String pkg : importedPackages)
             {
             try
             {
             if (hotDeployClassLoader != null) {
             clazz = hotDeployClassLoader.loadClass(pkg + '.' + className);
             } else {
             clazz = Reflections.classForName(pkg + '.' + className);
             }
             break;
             }
             catch (Exception e)
             {
             }
             }
             if (clazz == null) throw cnfe;
             }
            
             if (name == null)
             {
             if ( !clazz.isAnnotationPresent(Name.class) )
             {
             throw new IllegalArgumentException(
             "Component class must have @Name annotation or name must be specified in components.xml: " +
             clazz.getName());
             }
            
             name = clazz.getAnnotation(Name.class).value();
             }
            
             ComponentDescriptor descriptor = new ComponentDescriptor(name, clazz, scope, autoCreate, jndiName, installed, precedence);
             addComponentDescriptor(descriptor);
             installedComponentClasses.add(clazz);
             }
             else if (name == null)
             {
             throw new IllegalArgumentException("must specify either class or name in <component/> declaration");
             }
            
             for (Element prop : (List<Element>) component.elements())
             {
             String propName = prop.attributeValue("name");
             if (propName == null)
             {
             propName = prop.getQName().getName();
             }
             String qualifiedPropName = name + '.' + toCamelCase(propName, false);
             properties.put(qualifiedPropName, getPropertyValue(prop, qualifiedPropName, replacements));
             }
            
             for (Attribute prop: (List<Attribute>) component.attributes())
             {
             String attributeName = prop.getName();
             boolean isProperty = !"name".equals(attributeName) &&
             !"installed".equals(attributeName) &&
             !"scope".equals(attributeName) &&
             !"class".equals(attributeName) &&
             !"jndi-name".equals(attributeName) &&
             !"precedence".equals(attributeName) &&
             !"auto-create".equals(attributeName);
             if (isProperty)
             {
             String qualifiedPropName = name + '.' + toCamelCase( prop.getQName().getName(), false );
             properties.put(qualifiedPropName, getPropertyValue(prop, replacements));
             }
             }
             }
            
             private void addComponentDescriptor(ComponentDescriptor descriptor)
             {
             String name = descriptor.getName();
             Set<ComponentDescriptor> set = componentDescriptors.get(name);
             if (set==null)
             {
             set = new TreeSet<ComponentDescriptor>(new ComponentDescriptor.PrecedenceComparator());
             componentDescriptors.put(name, set);
             }
             if ( !set.isEmpty() )
             {
             log.info("two components with same name, higher precedence wins: " + name);
             }
             if ( !set.add(descriptor) )
             {
             throw new IllegalStateException("Two components with the same name and precedence: " + name);
             }
             }
            
             private Conversions.PropertyValue getPropertyValue(Attribute prop, Properties replacements)
             {
             return new Conversions.FlatPropertyValue( trimmedText(prop, replacements) );
             }
            
             @SuppressWarnings("unchecked")
             private Conversions.PropertyValue getPropertyValue(Element prop, String propName,
             Properties replacements)
             {
             List<Element> keyElements = prop.elements("key");
             List<Element> valueElements = prop.elements("value");
            
             if (valueElements.isEmpty() && keyElements.isEmpty())
             {
             return new Conversions.FlatPropertyValue(
             trimmedText(prop, propName, replacements));
             }
             else if (keyElements.isEmpty())
             {
             // a list-like structure
             int len = valueElements.size();
             String[] values = new String[len];
             for (int i = 0; i < len; i++)
             {
             values = trimmedText(valueElements.get(i), propName, replacements);
             }
             return new Conversions.MultiPropertyValue(values);
             }
             else
             {
             // a map-like structure
             if (valueElements.size() != keyElements.size())
             {
             throw new IllegalArgumentException("value elements must match key elements: "
             + propName);
             }
             Map<String, String> keyedValues = new HashMap<String, String>();
             for (int i = 0; i < keyElements.size(); i++)
             {
             String key = trimmedText(keyElements.get(i), propName, replacements);
             String value = trimmedText(valueElements.get(i), propName, replacements);
             keyedValues.put(key, value);
             }
             return new Conversions.AssociativePropertyValue(keyedValues);
             }
             }
            
             private String trimmedText(Element element, String propName, Properties replacements)
             {
             String text = element.getTextTrim();
             if (text == null)
             {
             throw new IllegalArgumentException("property value must be specified in element body: "
             + propName);
             }
             return replace(text, replacements);
             }
            
             private String trimmedText(Attribute attribute, Properties replacements)
             {
             return replace( attribute.getText(), replacements );
             }
            
             public Initialization setProperty(String name, Conversions.PropertyValue value)
             {
             properties.put(name, value);
             return this;
             }
            
             public Initialization init()
             {
             log.info("initializing Seam");
             Lifecycle.beginInitialization(servletContext);
             Contexts.getApplicationContext().set(Component.PROPERTIES, properties);
             initHotDeployClassLoader();
             initComponentsFromXmlDocuments();
             scanForHotDeployableComponents();
             scanForComponents();
            
             addComponent( new ComponentDescriptor(Init.class), Contexts.getApplicationContext() );
             Init init = (Init) Component.getInstance(Init.class, ScopeType.APPLICATION);
             ComponentDescriptor desc = findDescriptor(Jbpm.class);
             if (desc != null && desc.isInstalled())
             {
             init.setJbpmInstalled(true);
             }
             init.setTimestamp( System.currentTimeMillis() );
             init.setHotDeployPaths(hotDeployPaths);
            
             addSpecialComponents(init);
             installComponents(init);
             Lifecycle.endInitialization();
             log.info("done initializing Seam");
             return this;
             }
            
             public Initialization redeploy(HttpSession session)
             {
             log.info("redeploying");
             Lifecycle.beginReinitialization(servletContext, session);
             Init init = Init.instance();
             for ( String name: init.getHotDeployableComponents() )
             {
             Component component = Component.forName(name);
             ScopeType scope = component.getScope();
             if ( scope!=ScopeType.STATELESS && scope.isContextActive() )
             {
             scope.getContext().remove(name);
             }
             Contexts.getApplicationContext().remove(name + ".component");
             }
             init.getHotDeployableComponents().clear();
             Contexts.getApplicationContext().set(Component.PROPERTIES, properties);
             initHotDeployClassLoader();
             initComponentsFromXmlDocuments();
             scanForHotDeployableComponents();
             init.setTimestamp( System.currentTimeMillis() );
             init.setHotDeployPaths(hotDeployPaths);
             installComponents(init);
             Lifecycle.endInitialization();
             log.info("done redeploying");
             return this;
             }
            
             private void initHotDeployClassLoader()
             {
             ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
             try
             {
             URL resource = contextClassLoader.getResource("META-INF/debug.xhtml");
             if (resource!=null)
             {
             String path = resource.toExternalForm();
             String hotDeployDirectory = path.substring( 9, path.length()-46 ) + "dev";
             File directory = new File(hotDeployDirectory);
             if ( directory.exists() )
             {
             URL url = directory.toURI().toURL();
             /*File[] jars = directory.listFiles( new FilenameFilter() {
             public boolean accept(File file, String name) { return name.endsWith(".jar"); }
             } );
             URL[] urls = new URL[jars.length];
             for (int i=0; i<jars.length; i++)
             {
             urls = jars.toURL();
             }*/
             URL[] urls = {url};
             hotDeployClassLoader = new URLClassLoader(urls, contextClassLoader);
             hotDeployPaths = new File[] {directory};
             }
             }
             }
             catch (MalformedURLException mue)
             {
             throw new RuntimeException(mue);
             }
             }
            
             private void scanForHotDeployableComponents()
             {
             if ( hotDeployClassLoader!=null )
             {
             Set<Class<Object>> scannedClasses = new HashSet<Class<Object>>();
             scannedClasses.addAll( new ComponentScanner(null, hotDeployClassLoader).getClasses() );
             Set<Package> scannedPackages = new HashSet<Package>();
             for (Class<Object> scannedClass: scannedClasses)
             {
             installScannedClass(scannedPackages, scannedClass);
             }
             }
             }
            
             private void scanForComponents()
             {
             Set<Class<Object>> scannedClasses = new HashSet<Class<Object>>();
             scannedClasses.addAll( new ComponentScanner("seam.properties").getClasses() );
             scannedClasses.addAll( new ComponentScanner("META-INF/seam.properties").getClasses() );
             scannedClasses.addAll( new ComponentScanner("META-INF/components.xml").getClasses() );
            
             Set<Package> scannedPackages = new HashSet<Package>();
             for (Class<Object> scannedClass: scannedClasses)
             {
             installScannedClass(scannedPackages, scannedClass);
             }
             }
            
             private void installScannedClass(Set<Package> scannedPackages, Class<Object> scannedClass)
             {
             installScannedComponentAndRoles(scannedClass);
             installComponentsFromDescriptor( classDescriptorFilename(scannedClass), scannedClass );
             Package pkg = scannedClass.getPackage();
             if (pkg != null && scannedPackages.add(pkg) )
             {
             installComponentsFromDescriptor( packageDescriptorFilename(pkg), scannedClass );
             }
             }
            
             private static String classDescriptorFilename(Class<Object> scannedClass)
             {
             return scannedClass.getName().replace('.', '/') + ".component.xml";
             }
            
             private static String packageDescriptorFilename(Package pkg)
             {
             return pkg.getName().replace('.', '/') + "/components.xml";
             }
            
             private void installComponentsFromDescriptor(String fileName, Class clazz)
             {
             //note: this is correct, we do not need to scan other classloaders!
             InputStream stream = clazz.getClassLoader().getResourceAsStream(fileName);
             if (stream != null)
             {
             try
             {
             Properties replacements = getReplacements();
             Element root = XML.getRootElement(stream);
             if ( root.getName().equals("components") )
             {
             installComponentsFromXmlElements(root, replacements);
             }
             else
             {
             //TODO: namespaced components!!!
             installComponentFromXmlElement(
             root,
             root.attributeValue("name"),
             clazz.getName(), replacements
             );
             }
             }
             catch (Exception e)
             {
             throw new RuntimeException("error while reading " + fileName, e);
             }
             }
             }
            
             private void installScannedComponentAndRoles(Class<Object> scannedClass)
             {
             if (scannedClass.isAnnotationPresent(Name.class))
             {
             addComponentDescriptor(new ComponentDescriptor(scannedClass));
             }
             if (scannedClass.isAnnotationPresent(Role.class))
             {
             installRole(scannedClass, scannedClass.getAnnotation(Role.class));
             }
             if (scannedClass.isAnnotationPresent(Roles.class))
             {
             Role[] roles = scannedClass.getAnnotation(Roles.class).value();
             for (Role role : roles)
             {
             installRole(scannedClass, role);
             }
             }
             }
            
             private void installRole(Class<Object> scannedClass, Role role)
             {
             ScopeType scope = Seam.getComponentRoleScope(scannedClass, role);
             addComponentDescriptor( new ComponentDescriptor( role.name(), scannedClass, scope ) );
             }
            
             private void addNamespace(Package pkg)
             {
             if (pkg != null)
             {
             Namespace ns = pkg.getAnnotation(Namespace.class);
             if (ns != null)
             {
             log.info("Namespace: " + ns.value() + ", package: " + pkg.getName() + ", prefix: " + ns.prefix());
             namespaceMap.put(ns.value(), new NamespaceDescriptor(ns, pkg));
             }
             }
             }
            
             private void addNamespaces()
             {
             for ( Package pkg : new NamespaceScanner("META-INF/components.xml").getPackages() )
             {
             addNamespace(pkg);
             }
             for ( Package pkg : new NamespaceScanner("seam.properties").getPackages() )
             {
             addNamespace(pkg);
             }
             for ( Package pkg : new NamespaceScanner("META-INF/seam.properties").getPackages() )
             {
             addNamespace(pkg);
             }
             }
            
             private void initPropertiesFromServletContext()
             {
             Enumeration params = servletContext.getInitParameterNames();
             while (params.hasMoreElements())
             {
             String name = (String) params.nextElement();
             properties.put(name, new Conversions.FlatPropertyValue(servletContext
             .getInitParameter(name)));
             }
             }
            
             private void initPropertiesFromResource()
             {
             Properties props = loadFromResource("/seam.properties");
             for (Map.Entry me : props.entrySet())
             {
             properties.put((String) me.getKey(), new Conversions.FlatPropertyValue((String) me
             .getValue()));
             }
             }
            
             private void initJndiProperties()
             {
             Properties jndiProperties = new Properties();
             jndiProperties.putAll(loadFromResource("/jndi.properties"));
             jndiProperties.putAll(loadFromResource("/seam-jndi.properties"));
             Naming.setInitialContextProperties(jndiProperties);
             }
            
             private Properties loadFromResource(String resource)
             {
             Properties props = new Properties();
             InputStream stream = Resources.getResourceAsStream(resource, servletContext);
             if (stream != null)
             {
             log.info("reading properties from: " + resource);
             try
             {
             props.load(stream);
             }
             catch (IOException ioe)
             {
             log.error("could not read " + resource, ioe);
             }
             }
             else
             {
             log.debug("not found: " + resource);
             }
             return props;
             }
            
             protected ComponentDescriptor findDescriptor(Class<?> componentClass)
             {
             for (Set<ComponentDescriptor> components : componentDescriptors.values())
             {
             for (ComponentDescriptor component: components)
             {
             if ( component.getComponentClass().equals(componentClass) )
             {
             return component;
             }
             }
             }
             return null;
             }
            
             private void addSpecialComponents(Init init)
             {
             try
             {
             Reflections.classForName("org.jboss.cache.aop.PojoCache");
             addComponentDescriptor( new ComponentDescriptor(PojoCache.class, true) );
             }
             catch (ClassNotFoundException e) {}
             catch (NoClassDefFoundError e) {
             //temp solution due to broken JEMS installer portal profile!
             log.warn("Did not install PojoCache due to NoClassDefFoundError: " + e.getMessage());
             }
             }
            
             private void installComponents(Init init)
             {
             log.info("Installing components...");
             Context context = Contexts.getApplicationContext();
            
             DependencyManager manager = new DependencyManager(componentDescriptors);
            
             Set<ComponentDescriptor> installable = manager.installedSet();
             for (ComponentDescriptor componentDescriptor: installable) {
             String compName = componentDescriptor.getName() + COMPONENT_SUFFIX;
            
             if (!context.isSet(compName)) {
             addComponent(componentDescriptor, context);
            
             if (componentDescriptor.isAutoCreate()) {
             init.addAutocreateVariable( componentDescriptor.getName() );
             }
            
             if (componentDescriptor.isFilter()) {
             init.addInstalledFilter( componentDescriptor.getName() );
             }
            
             if (componentDescriptor.isResourceProvider()) {
             init.addResourceProvider( componentDescriptor.getName() );
             }
             }
             }
            
            
             for (FactoryDescriptor factoryDescriptor : factoryDescriptors)
             {
             if (factoryDescriptor.isValueBinding())
             {
             init.addFactoryValueBinding(factoryDescriptor.getName(), factoryDescriptor.getValue(),
             factoryDescriptor.getScope());
             }
             else
             {
             init.addFactoryMethodBinding(factoryDescriptor.getName(),
             factoryDescriptor.getMethod(), factoryDescriptor.getScope());
             }
             if (factoryDescriptor.isAutoCreate())
             {
             init.addAutocreateVariable(factoryDescriptor.getName());
             }
             }
            
             for (EventListenerDescriptor listenerDescriptor: eventListenerDescriptors.values())
             {
             for (String expression: listenerDescriptor.getListenerMethodBindings())
             {
             init.addObserverMethodBinding( listenerDescriptor.getType(), Expressions.instance().createMethodBinding(expression) );
             }
             }
             }
            
            
             /**
             * This actually creates a real Component and should only be called when
             * we want to install a component
             */
             protected void addComponent(ComponentDescriptor descriptor, Context context)
             {
             String name = descriptor.getName();
             String componentName = name + COMPONENT_SUFFIX;
             try
             {
             Component component = new Component(
             descriptor.getComponentClass(),
             name,
             descriptor.getScope(),
             descriptor.getJndiName()
             );
             context.set(componentName, component);
             if ( descriptor.getComponentClass().getClassLoader()==hotDeployClassLoader )
             {
             Init.instance().addHotDeployableComponent( component.getName() );
             }
             }
             catch (Throwable e)
             {
             throw new RuntimeException("Could not create Component: " + name, e);
             }
             }
            
             private static String toCamelCase(String hyphenated, boolean initialUpper)
             {
             StringTokenizer tokens = new StringTokenizer(hyphenated, "-");
             StringBuilder result = new StringBuilder( hyphenated.length() );
             String firstToken = tokens.nextToken();
             if (initialUpper)
             {
             result.append( Character.toUpperCase( firstToken.charAt(0) ) )
             .append( firstToken.substring(1) );
             }
             else
             {
             result.append(firstToken);
             }
             while ( tokens.hasMoreTokens() )
             {
             String token = tokens.nextToken();
             result.append( Character.toUpperCase( token.charAt(0) ) )
             .append( token.substring(1) );
             }
             return result.toString();
             }
            
            
            
             private static class EventListenerDescriptor
             {
             private String type;
             private List<String> listenerMethodBindings = new ArrayList<String>();
            
             EventListenerDescriptor(String type)
             {
             this.type = type;
             }
            
             public String getType()
             {
             return type;
             }
            
             public List<String> getListenerMethodBindings()
             {
             return listenerMethodBindings;
             }
            
             @Override
             public String toString()
             {
             return "EventListenerDescriptor(" + type + ')';
             }
             }
            
            
             }