org.romaframework.core.util.DynaBean.java Source code

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Here is the source code for org.romaframework.core.util.DynaBean.java

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/*
 * Copyright 20062-007 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.util;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Dynamic Bean. Acts in two ways: <li>Dynamic mode, you can get/set attributes without define them before. It works like an
 * HashMap.</li> <li>Static mode, you had to define the attributes before to get/set them.</li>
 * 
 * @author Luca Garulli (luca.garulli--at--assetdata.it)
 */
public class DynaBean implements Cloneable, Serializable {

    private static final long serialVersionUID = 2801912719184911296L;

    private final Map<String, Object> properties;
    private final boolean staticMode;
    private DynaBean parent;

    private static Log log = LogFactory.getLog(DynaBean.class);

    public DynaBean() {
        this(true);
    }

    public DynaBean(boolean iStaticMode) {
        staticMode = iStaticMode;
        properties = new HashMap<String, Object>();
    }

    /**
     * Define a new attribute with the default value
     * 
     * @param iName
     *          Attribute name
     * @param iDefaultValue
     *          Default attribute value
     */
    public void defineAttribute(String iName, Object iDefaultValue) {
        if (staticMode && properties.containsKey(iName))
            throw new DynaBeanException(
                    "Attribute " + iName + " is already defined for object " + getClass().getSimpleName());
        properties.put(iName, iDefaultValue);
    }

    public boolean setAttribute(String iName, Object iNewValue) {
        // GET CURRENT VALUE
        Object oldValue = getAttribute(iName);

        if (iNewValue == null && oldValue == null)
            // NO CHANGES
            return false;
        if (iNewValue != null && oldValue != null)
            if (iNewValue.equals(oldValue))
                // NO CHANGES
                return false;

        // STORE ALWAYS LOCALLY
        properties.put(iName, iNewValue);

        if (log.isDebugEnabled())
            log.debug("[DynaBean.setAttribute] " + iName + " = " + iNewValue);

        return true;
    }

    /**
     * Search the owner of the attribute and then return it. If the attribute is not found, a DynaBeanException is thrown if static
     * mode is true (by default).
     * 
     * @return attribute if found
     * @exception DynaBeanException
     *              if no attribute was found and static mode is true (by default)
     */
    public Object getAttribute(String iName) {
        return getAttributeOwner(iName, true).properties.get(iName);
    }

    public boolean existAttribute(String iName) {
        DynaBean owner = getAttributeOwner(iName, false);
        return owner != null && owner.properties.containsKey(iName);
    }

    public boolean isAttributeInherited(String iName) {
        DynaBean owner = getAttributeOwner(iName, true);
        return owner != this;
    }

    @Override
    public Object clone() throws CloneNotSupportedException {
        DynaBean cloned = new DynaBean(staticMode);
        cloned.parent = this;
        return cloned;
    }

    public Map<String, Object> getAttributes() {
        return populatetAttributes(new HashMap<String, Object>());
    }

    private Map<String, Object> populatetAttributes(Map<String, Object> iProperties) {
        if (parent != null)
            parent.populatetAttributes(iProperties);

        iProperties.putAll(properties);

        return iProperties;
    }

    @Override
    public String toString() {
        return getAttributes().toString();
    }

    private DynaBean getAttributeOwner(String iName, boolean iErrorNotFound) {
        DynaBean current = this;
        while (current != null && !current.properties.containsKey(iName))
            current = current.parent;

        if (iErrorNotFound && current == null && staticMode) {
            String msg = "Attribute " + iName + " not defined for object " + getClass().getSimpleName();
            log.error("[DynaBean.checkIfExists] Error: " + msg);
            throw new DynaBeanException(msg);
        }

        return current;
    }

    public DynaBean getParent() {
        return parent;
    }
}