org.romaframework.core.config.ComponentManager.java Source code

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Here is the source code for org.romaframework.core.config.ComponentManager.java

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/*
 * Copyright 2006-2009 Luca Garulli (luca.garulli--at--assetdata.it)
 *
 * 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.romaframework.core.config;

import java.util.Collection;
import java.util.HashMap;
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.springframework.util.StringUtils;

/**
 * Generic Manager of components instantiable in one shot by setComponents method (usually in configuration using Spring) and by
 * addComponent method at run-time.
 * 
 * Components will be registered with the name given from toString() call.
 * 
 * @author Luca Garulli (luca.garulli--at--assetdata.it)
 * 
 */
public class ComponentManager<C> {

    protected List<String> componentClassNames;
    protected Map<String, C> components;

    protected static Log log = LogFactory.getLog(ComponentManager.class);

    public ComponentManager() {
        components = new HashMap<String, C>();
    }

    /**
     * Setup multiple renders at startup
     * 
     * @param iComponentClassNames
     *          List of FrontEndRender instances to register.
     * @throws ClassNotFoundException
     * @throws IllegalAccessException
     * @throws InstantiationException
     */
    public void setComponents(List<String> iComponentClassNames)
            throws InstantiationException, IllegalAccessException, ClassNotFoundException {
        componentClassNames = iComponentClassNames;
    }

    protected void setupComponents() {
        String componentName;
        for (Iterator<String> it = componentClassNames.iterator(); it.hasNext();) {
            componentName = it.next();

            if (componentName == null || componentName.length() == 0)
                continue;

            componentName = componentName.replace('\t', ' ');
            componentName = componentName.replace('\n', ' ');
            componentName = componentName.trim();
            componentName = StringUtils.trimLeadingWhitespace(componentName);

            try {
                addComponent(componentName);
            } catch (Exception e) {
                log.error("[ComponentManager.setupComponents] Error" + e);
            }
        }
        componentClassNames = null;
    }

    /**
     * Register a single Manageable
     * 
     * @param iComponentClassName
     *          Manageable's class name
     */
    @SuppressWarnings("unchecked")
    public C addComponent(String iComponentClassName)
            throws InstantiationException, IllegalAccessException, ClassNotFoundException {
        return addComponent((Class<C>) Class.forName(iComponentClassName));
    }

    /**
     * Register a single Manageable
     * 
     * @param iComponentClass
     *          Manageable's class
     */
    public C addComponent(Class<? extends C> iComponentClass)
            throws InstantiationException, IllegalAccessException {
        // INSTANTIATE THE COMPONENT
        C component = (C) iComponentClass.newInstance();

        // REGISTER THE COMPONENT INSTANCE WITH ITS NAME (GIVEN FROM toString()
        // METHOD)
        components.put(component.toString(), component);
        return component;
    }

    public void setComponentInstances(Collection<C> iComponentInstances) {
        if (iComponentInstances == null)
            return;

        for (C instance : iComponentInstances)
            addComponentInstance(instance);
    }

    /**
     * Register a single Component
     * 
     * @param iComponentClassName
     *          Manageable's class name
     */
    public void addComponentInstance(C iComponentInstance) {
        // REGISTER THE COMPONENT INSTANCE WITH ITS NAME (GIVEN FROM toString()
        // METHOD)
        addComponentInstance(iComponentInstance.toString(), iComponentInstance);
    }

    /**
     * Register a single Component
     * 
     * @param iComponentClassName
     *          Manageable's class name
     */
    public void addComponentInstance(String iComponentName, C iComponentInstance) {
        // REGISTER THE COMPONENT INSTANCE WITH ITS NAME (GIVEN FROM toString()
        // METHOD)
        components.put(iComponentName, iComponentInstance);
    }

    public Set<String> getComponentNames() {
        if (componentClassNames != null) {
            synchronized (components) {
                if (componentClassNames != null)
                    setupComponents();
            }
        }
        return components.keySet();
    }

    /**
     * Get the render by the key
     * 
     * @param iKey
     *          String that identify the render (the same that FrontEndRender instance uses to register to the PluginManager
     * @return FrontEndRender if found, otherwise null
     */
    public C getComponent(String iKey) {
        if (componentClassNames != null) {
            synchronized (components) {
                if (componentClassNames != null)
                    setupComponents();
            }
        }
        return components.get(iKey);
    }
}