org.omnaest.utils.beans.replicator.InstanceAccessorForIterable.java Source code

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Here is the source code for org.omnaest.utils.beans.replicator.InstanceAccessorForIterable.java

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/*******************************************************************************
 * Copyright 2012 Danny Kunz
 * 
 * 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.omnaest.utils.beans.replicator;

import java.util.Collection;
import java.util.List;
import java.util.Map;

import org.apache.commons.collections.CollectionUtils;
import org.omnaest.utils.operation.foreach.Range;
import org.omnaest.utils.structure.collection.list.ListUtils;
import org.omnaest.utils.structure.element.converter.ElementConverter;
import org.omnaest.utils.structure.element.converter.ElementConverterNumberToString;
import org.omnaest.utils.structure.iterator.IterableUtils;
import org.omnaest.utils.structure.map.MapUtils;

/**
 * @author Omnaest
 */
class InstanceAccessorForIterable implements InstanceAccessor {
    /* ************************************************** Constants *************************************************** */
    private static final long serialVersionUID = -2295601391716506677L;
    /* ************************************** Variables / State (internal/hiding) ************************************* */
    private final Class<?> type;

    /* *************************************************** Methods **************************************************** */

    /**
     * @see InstanceAccessorForIterable
     * @param type
     */
    InstanceAccessorForIterable(Class<?> type) {
        this.type = type;
    }

    @Override
    public PropertyAccessor getPropertyAccessor(final String propertyName, Object instance) {
        final List<Object> list = determineWrappedListInstanceFrom(instance);
        final List<Object> nativeList = determineListInstanceFrom(instance);
        final Collection<Object> nativeCollection = determineCollectionInstanceFrom(instance);
        final int index = Integer.valueOf(propertyName);
        return new PropertyAccessor() {
            private static final long serialVersionUID = 704781840105684736L;

            @Override
            public void setValue(Object value) {
                if (nativeList != null) {
                    ListUtils.set(nativeList, index, value);
                } else if (nativeCollection != null) {
                    nativeCollection.add(value);
                } else {
                    throw new UnsupportedOperationException(
                            "Iterable cannot be written since it does not allow to add elements to it");
                }
            }

            @Override
            public Object getValue() {
                return ListUtils.get(list, index);
            }

            @Override
            public Class<?> getType() {
                final Object value = this.getValue();
                return value != null ? value.getClass() : null;
            }

            @Override
            public String getPropertyName() {
                return propertyName;
            }

        };
    }

    @Override
    public Iterable<String> getPropertyNameIterable(Object instance) {
        final int lastIndex = determineSizeFrom(instance) - 1;
        final Iterable<? extends Number> range = new Range(0, lastIndex);
        final ElementConverter<Number, String> elementConverter = new ElementConverterNumberToString();
        return IterableUtils.<Number, String>adapter(range, elementConverter);
    }

    @SuppressWarnings("unchecked")
    private static int determineSizeFrom(Object instance) {
        return IterableUtils.size((Iterable<Object>) instance);
    }

    @SuppressWarnings("unchecked")
    private static List<Object> determineListInstanceFrom(Object instance) {
        if (instance instanceof List) {
            return (List<Object>) instance;
        }
        return null;
    }

    @SuppressWarnings("unchecked")
    private static List<Object> determineWrappedListInstanceFrom(Object instance) {
        if (instance instanceof List) {
            return (List<Object>) instance;
        }
        return ListUtils.valueOf((Iterable<Object>) instance);
    }

    @SuppressWarnings("unchecked")
    private static Collection<Object> determineCollectionInstanceFrom(Object instance) {
        if (instance instanceof Collection) {
            return (Collection<Object>) instance;
        }
        return null;
    }

    @Override
    public Class<?> getType() {
        return this.type;
    }

    @Override
    @SuppressWarnings("unchecked")
    public Map<String, Object> determineFactoryMetaInformation(Object instance) {
        int size = 0;
        if (instance instanceof Collection) {
            size = CollectionUtils.size(instance);
        } else if (instance instanceof Iterable) {
            size = IterableUtils.size((Iterable<Object>) instance);
        }
        final Map<String, Object> retmap = MapUtils.builder().put("size", (Object) size).buildAs().hashMap();
        return retmap;
    }
}