org.apache.wicket.model.Model.java Source code

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Here is the source code for org.apache.wicket.model.Model.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.wicket.model;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.wicket.model.util.CollectionModel;
import org.apache.wicket.model.util.ListModel;
import org.apache.wicket.model.util.MapModel;
import org.apache.wicket.model.util.SetModel;
import org.apache.wicket.util.lang.Objects;

/**
 * <code>Model</code> is the basic implementation of an <code>IModel</code>. It just wraps a simple
 * model object. The model object must be serializable, as it is stored in the session. If you have
 * large objects to store, consider using {@link org.apache.wicket.model.LoadableDetachableModel}
 * instead of this class.
 * 
 * @author Chris Turner
 * @author Eelco Hillenius
 * 
 * @param <T>
 *            The type of the Model Object
 */
public class Model<T extends Serializable> implements IObjectClassAwareModel<T> {
    private static final long serialVersionUID = 1L;

    /** Backing object. */
    private T object;

    /**
     * Construct the model without providing an object.
     */
    public Model() {
    }

    /**
     * Construct the model, setting the given object as the wrapped object.
     * 
     * @param object
     *            The model object proper
     */
    public Model(final T object) {
        setObject(object);
    }

    /**
     * Factory method for models that contain lists. This factory method will automatically rebuild
     * a non-serializable <code>list</code> into a serializable one.
     * 
     * @param <C>
     *            model type
     * @param list
     *            The List, which may or may not be Serializable
     * @return A Model object wrapping the List
     */
    public static <C> IModel<List<C>> ofList(final List<C> list) {
        return new ListModel<>(list);
    }

    /**
     * Factory method for models that contain maps. This factory method will automatically rebuild a
     * non-serializable <code>map</code> into a serializable one.
     * 
     * @param <K>
     *            key type in map
     * @param <V>
     *            value type in map
     * @param map
     *            The Map, which may or may not be Serializable
     * @return A Model object wrapping the Map
     */
    public static <K, V> IModel<Map<K, V>> ofMap(final Map<K, V> map) {
        return new MapModel<>(map);
    }

    /**
     * Factory method for models that contain sets. This factory method will automatically rebuild a
     * non-serializable <code>set</code> into a serializable one.
     * 
     * @param <C>
     *            model type
     * @param set
     *            The Set, which may or may not be Serializable
     * @return A Model object wrapping the Set
     */
    public static <C> IModel<Set<C>> ofSet(final Set<C> set) {
        return new SetModel<>(set);
    }

    /**
     * Factory method for models that contain collections. This factory method will automatically
     * rebuild a non-serializable <code>collection</code> into a serializable {@link ArrayList}.
     * 
     * @param <C>
     *            model type
     * @param collection
     *            The Collection, which may or may not be Serializable
     * @return A Model object wrapping the Set
     */
    public static <C> IModel<Collection<C>> of(final Collection<C> collection) {
        return new CollectionModel<>(collection);
    }

    /**
     * Factory methods for Model which uses type inference to make code shorter. Equivalent to
     * <code>new Model<TypeOfObject>(object)</code>.
     * 
     * @param <T>
     * @param object
     * @return Model that contains <code>object</code>
     */
    public static <T extends Serializable> Model<T> of(T object) {
        return new Model<>(object);
    }

    /**
     * Factory methods for Model which uses type inference to make code shorter. Equivalent to
     * <code>new Model<TypeOfObject>()</code>.
     * 
     * @param <T>
     * @return Model that contains <code>object</code>
     */
    public static <T extends Serializable> Model<T> of() {
        return new Model<>();
    }

    @Override
    public T getObject() {
        return object;
    }

    /**
     * Set the model object; calls setObject(java.io.Serializable). The model object must be
     * serializable, as it is stored in the session
     * 
     * @param object
     *            the model object
     * @see org.apache.wicket.model.IModel#setObject(Object)
     */
    @Override
    public void setObject(final T object) {
        this.object = object;
    }

    @Override
    public void detach() {
        if (object instanceof IDetachable) {
            ((IDetachable) object).detach();
        }
    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder("Model:classname=[");
        sb.append(getClass().getName()).append(']');
        sb.append(":object=[").append(object).append(']');
        return sb.toString();
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(object);
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (!(obj instanceof Model<?>)) {
            return false;
        }
        Model<?> that = (Model<?>) obj;
        return Objects.equal(object, that.object);
    }

    @SuppressWarnings("unchecked")
    @Override
    public Class<T> getObjectClass() {
        return object != null ? (Class<T>) object.getClass() : null;
    }
}