| // Copyright 2004 The Apache Software Foundation |
| // |
| // Licensed 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.tapestry.bean; |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.tapestry.ApplicationRuntimeException; |
| import org.apache.tapestry.IBeanProvider; |
| import org.apache.tapestry.IComponent; |
| import org.apache.tapestry.IEngine; |
| import org.apache.tapestry.IResourceResolver; |
| import org.apache.tapestry.Tapestry; |
| import org.apache.tapestry.event.PageDetachListener; |
| import org.apache.tapestry.event.PageEvent; |
| import org.apache.tapestry.event.PageRenderListener; |
| import org.apache.tapestry.spec.BeanLifecycle; |
| import org.apache.tapestry.spec.IBeanSpecification; |
| import org.apache.tapestry.spec.IComponentSpecification; |
| |
| /** |
| * Basic implementation of the {@link IBeanProvider} interface. |
| * |
| * @author Howard Lewis Ship |
| * @version $Id$ |
| * @since 1.0.4 |
| **/ |
| |
| public class BeanProvider implements IBeanProvider, PageDetachListener, PageRenderListener |
| { |
| private static final Log LOG = LogFactory.getLog(BeanProvider.class); |
| |
| /** |
| * Indicates whether this instance has been registered with its |
| * page as a PageDetachListener. Registration only occurs |
| * the first time a bean with lifecycle REQUEST is instantiated. |
| * |
| **/ |
| |
| private boolean _registeredForDetach = false; |
| |
| /** |
| * Indicates whether this instance has been registered as a render |
| * listener with the page. |
| * |
| **/ |
| |
| private boolean _registeredForRender = false; |
| |
| /** |
| * The component for which beans are being created and tracked. |
| * |
| **/ |
| |
| private IComponent _component; |
| |
| /** |
| * Used for instantiating classes. |
| * |
| **/ |
| |
| private IResourceResolver _resolver; |
| |
| /** |
| * Map of beans, keyed on name. |
| * |
| **/ |
| |
| private Map _beans; |
| |
| /** |
| * Set of bean names provided by this provider. |
| * |
| * @since 2.2 |
| * |
| **/ |
| |
| private Set _beanNames; |
| |
| public BeanProvider(IComponent component) |
| { |
| this._component = component; |
| IEngine engine = component.getPage().getEngine(); |
| _resolver = engine.getResourceResolver(); |
| |
| if (LOG.isDebugEnabled()) |
| LOG.debug("Created BeanProvider for " + component); |
| |
| } |
| |
| /** @since 1.0.6 **/ |
| |
| public Collection getBeanNames() |
| { |
| if (_beanNames == null) |
| { |
| Collection c = _component.getSpecification().getBeanNames(); |
| |
| if (c == null || c.isEmpty()) |
| _beanNames = Collections.EMPTY_SET; |
| else |
| _beanNames = Collections.unmodifiableSet(new HashSet(c)); |
| } |
| |
| return _beanNames; |
| } |
| |
| /** |
| * @since 1.0.5 |
| * |
| **/ |
| |
| public IComponent getComponent() |
| { |
| return _component; |
| } |
| |
| public Object getBean(String name) |
| { |
| Object bean = null; |
| |
| if (_beans != null) |
| bean = _beans.get(name); |
| |
| if (bean != null) |
| return bean; |
| |
| IBeanSpecification spec = _component.getSpecification().getBeanSpecification(name); |
| |
| if (spec == null) |
| throw new ApplicationRuntimeException( |
| Tapestry.format( |
| "BeanProvider.bean-not-defined", |
| _component.getExtendedId(), |
| name)); |
| |
| bean = instantiateBean(name, spec); |
| |
| BeanLifecycle lifecycle = spec.getLifecycle(); |
| |
| if (lifecycle == BeanLifecycle.NONE) |
| return bean; |
| |
| if (_beans == null) |
| _beans = new HashMap(); |
| |
| _beans.put(name, bean); |
| |
| // The first time in a request that a REQUEST lifecycle bean is created, |
| // register with the page to be notified at the end of the |
| // request cycle. |
| |
| if (lifecycle == BeanLifecycle.REQUEST && !_registeredForDetach) |
| { |
| _component.getPage().addPageDetachListener(this); |
| _registeredForDetach = true; |
| } |
| |
| if (lifecycle == BeanLifecycle.RENDER && !_registeredForRender) |
| { |
| _component.getPage().addPageRenderListener(this); |
| _registeredForRender = true; |
| } |
| |
| // No need to register if a PAGE lifecycle bean; those can stick around |
| // forever. |
| |
| return bean; |
| } |
| |
| private Object instantiateBean(String beanName, IBeanSpecification spec) |
| { |
| String className = spec.getClassName(); |
| Object bean = null; |
| |
| if (LOG.isDebugEnabled()) |
| LOG.debug("Instantiating instance of " + className); |
| |
| // Do it the hard way! |
| |
| try |
| { |
| Class beanClass = _resolver.findClass(className); |
| |
| bean = beanClass.newInstance(); |
| } |
| catch (Exception ex) |
| { |
| |
| throw new ApplicationRuntimeException( |
| Tapestry.format( |
| "BeanProvider.instantiation-error", |
| new Object[] { |
| beanName, |
| _component.getExtendedId(), |
| className, |
| ex.getMessage()}), |
| spec.getLocation(), |
| ex); |
| } |
| |
| // OK, have the bean, have to initialize it. |
| |
| List initializers = spec.getInitializers(); |
| |
| if (initializers == null) |
| return bean; |
| |
| Iterator i = initializers.iterator(); |
| while (i.hasNext()) |
| { |
| IBeanInitializer iz = (IBeanInitializer) i.next(); |
| |
| if (LOG.isDebugEnabled()) |
| LOG.debug("Initializing property " + iz.getPropertyName()); |
| |
| iz.setBeanProperty(this, bean); |
| } |
| |
| return bean; |
| } |
| |
| /** |
| * Removes all beans with the REQUEST lifecycle. Beans with |
| * the PAGE lifecycle stick around, and beans with no lifecycle |
| * were never stored in the first place. |
| * |
| **/ |
| |
| public void pageDetached(PageEvent event) |
| { |
| removeBeans(BeanLifecycle.REQUEST); |
| } |
| |
| /** |
| * Removes any beans with the specified lifecycle. |
| * |
| * @since 2.2 |
| * |
| **/ |
| |
| private void removeBeans(BeanLifecycle lifecycle) |
| { |
| if (_beans == null) |
| return; |
| |
| IComponentSpecification spec = null; |
| |
| Iterator i = _beans.entrySet().iterator(); |
| while (i.hasNext()) |
| { |
| Map.Entry e = (Map.Entry) i.next(); |
| String name = (String) e.getKey(); |
| |
| if (spec == null) |
| spec = _component.getSpecification(); |
| |
| IBeanSpecification s = spec.getBeanSpecification(name); |
| |
| if (s.getLifecycle() == lifecycle) |
| { |
| Object bean = e.getValue(); |
| |
| if (LOG.isDebugEnabled()) |
| LOG.debug("Removing " + lifecycle.getName() + " bean " + name + ": " + bean); |
| |
| i.remove(); |
| } |
| } |
| } |
| |
| /** @since 1.0.8 **/ |
| |
| public IResourceResolver getResourceResolver() |
| { |
| return _resolver; |
| } |
| |
| /** @since 2.2 **/ |
| |
| public void pageBeginRender(PageEvent event) |
| { |
| } |
| |
| /** @since 2.2 **/ |
| |
| public void pageEndRender(PageEvent event) |
| { |
| removeBeans(BeanLifecycle.RENDER); |
| } |
| |
| /** @since 2.2 **/ |
| |
| public boolean canProvideBean(String name) |
| { |
| return getBeanNames().contains(name); |
| } |
| |
| } |