/*
* Copyright 2002-2008 the original author or authors.
*
* 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.springframework.web.portlet;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Set;
import javax.portlet.GenericPortlet;
import javax.portlet.PortletConfig;
import javax.portlet.PortletContext;
import javax.portlet.PortletException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeanWrapper;
import org.springframework.beans.BeansException;
import org.springframework.beans.MutablePropertyValues;
import org.springframework.beans.PropertyAccessorFactory;
import org.springframework.beans.PropertyValue;
import org.springframework.beans.PropertyValues;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceEditor;
import org.springframework.core.io.ResourceLoader;
import org.springframework.util.StringUtils;
import org.springframework.web.portlet.context.PortletContextResourceLoader;
/**
* Simple extension of <code>javax.portlet.GenericPortlet</code> that treats
* its config parameters as bean properties.
*
* <p>A very handy superclass for any type of portlet. Type conversion is automatic.
* It is also possible for subclasses to specify required properties.
*
* <p>This portlet leaves request handling to subclasses, inheriting the default
* behaviour of GenericPortlet (<code>doDispatch</code>, <code>processAction</code>, etc).
*
* <p>This portlet superclass has no dependency on a Spring application context,
* in contrast to the FrameworkPortlet class which loads its own context.
*
* @author William G. Thompson, Jr.
* @author John A. Lewis
* @author Juergen Hoeller
* @since 2.0
* @see #addRequiredProperty
* @see #initPortletBean
* @see #doDispatch
* @see #processAction
* @see FrameworkPortlet
*/
public abstract class GenericPortletBean extends GenericPortlet {
/** Logger available to subclasses */
protected final Log logger = LogFactory.getLog(getClass());
/**
* Set of required properties (Strings) that must be supplied as
* config parameters to this portlet.
*/
private final Set<String> requiredProperties = new HashSet<String>();
/**
* Subclasses can invoke this method to specify that this property
* (which must match a JavaBean property they expose) is mandatory,
* and must be supplied as a config parameter. This method would
* normally be called from a subclass constructor.
* @param property name of the required property
*/
protected final void addRequiredProperty(String property) {
this.requiredProperties.add(property);
}
/**
* Map config parameters onto bean properties of this portlet, and
* invoke subclass initialization.
* @throws PortletException if bean properties are invalid (or required
* properties are missing), or if subclass initialization fails.
*/
@Override
public final void init() throws PortletException {
if (logger.isInfoEnabled()) {
logger.info("Initializing portlet '" + getPortletName() + "'");
}
// Set bean properties from init parameters.
try {
PropertyValues pvs = new PortletConfigPropertyValues(getPortletConfig(), this.requiredProperties);
BeanWrapper bw = PropertyAccessorFactory.forBeanPropertyAccess(this);
ResourceLoader resourceLoader = new PortletContextResourceLoader(getPortletContext());
bw.registerCustomEditor(Resource.class, new ResourceEditor(resourceLoader));
initBeanWrapper(bw);
bw.setPropertyValues(pvs, true);
}
catch (BeansException ex) {
logger.error("Failed to set bean properties on portlet '" + getPortletName() + "'", ex);
throw ex;
}
// let subclasses do whatever initialization they like
initPortletBean();
if (logger.isInfoEnabled()) {
logger.info("Portlet '" + getPortletName() + "' configured successfully");
}
}
/**
* Initialize the BeanWrapper for this GenericPortletBean,
* possibly with custom editors.
* @param bw the BeanWrapper to initialize
* @throws BeansException if thrown by BeanWrapper methods
* @see org.springframework.beans.BeanWrapper#registerCustomEditor
*/
protected void initBeanWrapper(BeanWrapper bw) throws BeansException {
}
/**
* Overridden method that simply returns <code>null</code> when no
* PortletConfig set yet.
* @see #getPortletConfig()
*/
@Override
public final String getPortletName() {
return (getPortletConfig() != null ? getPortletConfig().getPortletName() : null);
}
/**
* Overridden method that simply returns <code>null</code> when no
* PortletConfig set yet.
* @see #getPortletConfig()
*/
@Override
public final PortletContext getPortletContext() {
return (getPortletConfig() != null ? getPortletConfig().getPortletContext() : null);
}
/**
* Subclasses may override this to perform custom initialization.
* All bean properties of this portlet will have been set before this
* method is invoked. This default implementation does nothing.
* @throws PortletException if subclass initialization fails
*/
protected void initPortletBean() throws PortletException {
}
/**
* PropertyValues implementation created from PortletConfig init parameters.
*/
private static class PortletConfigPropertyValues extends MutablePropertyValues {
/**
* Create new PortletConfigPropertyValues.
* @param config PortletConfig we'll use to take PropertyValues from
* @param requiredProperties set of property names we need, where
* we can't accept default values
* @throws PortletException if any required properties are missing
*/
private PortletConfigPropertyValues(PortletConfig config, Set<String> requiredProperties)
throws PortletException {
Set<String> missingProps = (requiredProperties != null && !requiredProperties.isEmpty()) ?
new HashSet<String>(requiredProperties) : null;
Enumeration en = config.getInitParameterNames();
while (en.hasMoreElements()) {
String property = (String) en.nextElement();
Object value = config.getInitParameter(property);
addPropertyValue(new PropertyValue(property, value));
if (missingProps != null) {
missingProps.remove(property);
}
}
// fail if we are still missing properties
if (missingProps != null && missingProps.size() > 0) {
throw new PortletException(
"Initialization from PortletConfig for portlet '" + config.getPortletName() +
"' failed; the following required properties were missing: " +
StringUtils.collectionToDelimitedString(missingProps, ", "));
}
}
}
}
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