org.eclipse.nebula.widgets.nattable.data.ReflectiveColumnPropertyAccessor.java Source code

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Here is the source code for org.eclipse.nebula.widgets.nattable.data.ReflectiveColumnPropertyAccessor.java

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/*******************************************************************************
 * Copyright (c) 2012, 2013 Original authors and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Original authors and others - initial API and implementation
 ******************************************************************************/
package org.eclipse.nebula.widgets.nattable.data;

import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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

/**
 * Convenience class which uses java reflection to get/set property names
 *  from the row bean. It looks for getter methods for reading and setter
 *  methods for writing according to the Java conventions.
 *
 * @param <R> type of the row object/bean
 */
public class ReflectiveColumnPropertyAccessor<R> implements IColumnPropertyAccessor<R> {

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

    private final List<String> propertyNames;

    private Map<String, PropertyDescriptor> propertyDescriptorMap;

    /**
     * @param propertyNames of the members of the row bean
     */
    public ReflectiveColumnPropertyAccessor(String[] propertyNames) {
        this.propertyNames = Arrays.asList(propertyNames);
    }

    public int getColumnCount() {
        return propertyNames.size();
    }

    public Object getDataValue(R rowObj, int columnIndex) {
        try {
            PropertyDescriptor propertyDesc = getPropertyDescriptor(rowObj, columnIndex);
            Method readMethod = propertyDesc.getReadMethod();
            return readMethod.invoke(rowObj);
        } catch (Exception e) {
            log.warn(e);
            throw new RuntimeException(e);
        }
    }

    public void setDataValue(R rowObj, int columnIndex, Object newValue) {
        try {
            PropertyDescriptor propertyDesc = getPropertyDescriptor(rowObj, columnIndex);
            Method writeMethod = propertyDesc.getWriteMethod();
            if (writeMethod == null) {
                throw new RuntimeException(
                        "Setter method not found in backing bean for value at column index: " + columnIndex); //$NON-NLS-1$
            }
            writeMethod.invoke(rowObj, newValue);
        } catch (IllegalArgumentException ex) {
            log.error("Data type being set does not match the data type of the setter method in the backing bean", //$NON-NLS-1$
                    ex);
        } catch (Exception e) {
            log.error(e);
            throw new RuntimeException("Error while setting data value"); //$NON-NLS-1$
        }
    };

    public String getColumnProperty(int columnIndex) {
        return propertyNames.get(columnIndex);
    }

    public int getColumnIndex(String propertyName) {
        return propertyNames.indexOf(propertyName);
    }

    private PropertyDescriptor getPropertyDescriptor(R rowObj, int columnIndex) throws IntrospectionException {
        if (propertyDescriptorMap == null) {
            propertyDescriptorMap = new HashMap<String, PropertyDescriptor>();
            PropertyDescriptor[] propertyDescriptors = Introspector.getBeanInfo(rowObj.getClass())
                    .getPropertyDescriptors();
            for (PropertyDescriptor propertyDescriptor : propertyDescriptors) {
                propertyDescriptorMap.put(propertyDescriptor.getName(), propertyDescriptor);
            }
        }

        final String propertyName = propertyNames.get(columnIndex);
        return propertyDescriptorMap.get(propertyName);
    }

}