org.nuclos.common.collect.collectable.AbstractCollectableBean.java Source code

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Here is the source code for org.nuclos.common.collect.collectable.AbstractCollectableBean.java

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//Copyright (C) 2010  Novabit Informationssysteme GmbH
//
//This file is part of Nuclos.
//
//Nuclos is free software: you can redistribute it and/or modify
//it under the terms of the GNU Affero General Public License as published by
//the Free Software Foundation, either version 3 of the License, or
//(at your option) any later version.
//
//Nuclos is distributed in the hope that it will be useful,
//but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//GNU Affero General Public License for more details.
//
//You should have received a copy of the GNU Affero General Public License
//along with Nuclos.  If not, see <http://www.gnu.org/licenses/>.
package org.nuclos.common.collect.collectable;

import java.lang.reflect.InvocationTargetException;

import org.apache.commons.beanutils.PropertyUtils;
import org.apache.commons.lang.NullArgumentException;
import org.apache.log4j.Logger;

import org.nuclos.common.collection.Transformer;
import org.nuclos.common2.exception.CommonFatalException;

/**
 * Abstract (basic) implementation of a <code>Collectable</code> wrapping a JavaBean.
 * The methods that return meta information are delegated to a <code>CollectableEntity</code> object.
 * <br>
 * <br>Created by Novabit Informationssysteme GmbH
 * <br>Please visit <a href="http://www.novabit.de">www.novabit.de</a>
 *
 * @author   <a href="mailto:Christoph.Radig@novabit.de">Christoph.Radig</a>
 * @version 01.00.00
 */
public abstract class AbstractCollectableBean<T> extends AbstractCollectable {

    private static final Logger log = Logger.getLogger(AbstractCollectableBean.class);

    private final T tBean;

    /**
     * @param tBean
     * @precondition tBean != null
     */
    protected AbstractCollectableBean(T tBean) {
        if (tBean == null) {
            throw new NullArgumentException("tBean");
        }
        this.tBean = tBean;
    }

    /**
     * @return the <code>CollectableEntity</code> for this <code>Collectable</code>.
     */
    protected abstract CollectableEntity getCollectableEntity();

    /**
     * @return the wrapped JavaBean.
     * @postcondition result != null
     */
    protected T getBean() {
        return this.tBean;
    }

    @Override
    public CollectableField getField(String sFieldName) {
        return new BeanPropertyCollectableField(this.getBean(), sFieldName, this.getCollectableEntity());
    }

    @Override
    public void setField(String sFieldName, CollectableField clctfValue) {
        this.setCollectableFieldUsingBeanProperty(this.getBean(), sFieldName, clctfValue);

        assert this.getField(sFieldName).equals(clctfValue) : "value of field " + sFieldName + " is "
                + this.getField(sFieldName) + " - expected: " + clctfValue;
    }

    /**
     * Helper method for setField() implementations. Ignores failure of setting the value.
     * @param oBean
     * @param sFieldName
     * @param clctfValue
     */
    protected void setCollectableFieldUsingBeanProperty(Object oBean, String sFieldName,
            CollectableField clctfValue) {
        this.setCollectableFieldUsingBeanProperty(oBean, sFieldName, clctfValue, true);
    }

    /**
     * Helper method for setField() implementations.
     * @param oBean
     * @param sFieldName
     * @param clctfValue
     * @param bIgnoreFailureOfSetValue Setting the value may not be supported by some id fields in some VOs. If true,
     *       we try to do so, but ignore NoSuchMethodException.
     */
    protected void setCollectableFieldUsingBeanProperty(Object oBean, String sFieldName,
            CollectableField clctfValue, boolean bIgnoreFailureOfSetValue) {
        try {
            setProperty(oBean, sFieldName, clctfValue.getValue());
        } catch (NoSuchMethodException ex) {
            if (bIgnoreFailureOfSetValue) {
                log.warn("CollectableField \"" + sFieldName + "\" could not be set.", ex);
                /** @todo A cleaner alternative would be to introduce the concept of "read only value" id fields. */
            } else {
                throw new CommonFatalException(ex);
            }
        }

        if (this.getCollectableEntity().getEntityField(sFieldName).isIdField()) {
            try {
                setProperty(oBean, sFieldName + "Id", clctfValue.getValueId());
            } catch (NoSuchMethodException ex) {
                throw new CommonFatalException(ex);
            }
        }
    }

    @Override
    public String toString() {
        final StringBuilder result = new StringBuilder();
        result.append(getClass().getName()).append("[");
        result.append("vo=").append(getBean());
        result.append(",id=").append(getId());
        result.append(",label=").append(getIdentifierLabel());
        result.append(",complete=").append(isComplete());
        result.append("]");
        return result.toString();
    }

    /**
     * Utility method to set a bean property.
     * @param sPropertyName
     * @param oValue
     * @todo Replace with CollectableElisaValueObject.setPropertyValue implementation and move to BeanUtils.
     */
    protected static void setProperty(Object oBean, String sPropertyName, Object oValue)
            throws NoSuchMethodException {
        try {
            PropertyUtils.setSimpleProperty(oBean, sPropertyName, oValue);
            /** @todo BeanUtils.setProperty(tBean, sPropertyName, oValue); */
        } catch (IllegalAccessException ex) {
            throw new CommonFatalException(getErrorMessage(sPropertyName, oBean, true), ex);
        } catch (InvocationTargetException ex) {
            throw new CommonFatalException(getErrorMessage(sPropertyName, oBean, true), ex.getCause());
        } catch (IllegalArgumentException ex) {
            throw new CommonFatalException(getErrorMessage(sPropertyName, oBean, true), ex);
        }
    }

    /**
     * @param sPropertyName
     * @param oBean
     * @param bSet true: "set" - false: "get"
     * @return error message
     */
    protected static String getErrorMessage(String sPropertyName, Object oBean, boolean bSet) {
        if (bSet)
            return "Failed to set property \"" + sPropertyName + "\" on bean \"" + oBean + "\".";
        else
            return "Failed to get property \"" + sPropertyName + "\" on bean \"" + oBean + "\".";
    }

    /**
     * Transformer: extracts the wrapped bean from a given Collectable.
     */
    public static class ExtractBean<T> implements Transformer<AbstractCollectableBean<T>, T> {
        @Override
        public T transform(AbstractCollectableBean<T> clctbean) {
            return clctbean.getBean();
        }
    }

} // class AbstractCollectableBean