org.springframework.data.mapping.model.SimpleTypeHolder.java Source code

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Here is the source code for org.springframework.data.mapping.model.SimpleTypeHolder.java

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/*
 * Copyright 2011-2019 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.data.mapping.model;

import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.HashSet;
import java.util.Locale;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.WeakHashMap;

import org.springframework.util.Assert;

/**
 * Simple container to hold a set of types to be considered simple types.
 *
 * @author Oliver Gierke
 * @author Christoph Strobl
 * @author Mark Paluch
 */
public class SimpleTypeHolder {

    private static final Set<Class<?>> DEFAULTS = new HashSet<Class<?>>() {

        private static final long serialVersionUID = -1738594126505221500L;

        {
            add(boolean.class);
            add(boolean[].class);
            add(long.class);
            add(long[].class);
            add(short.class);
            add(short[].class);
            add(int.class);
            add(int[].class);
            add(byte.class);
            add(byte[].class);
            add(float.class);
            add(float[].class);
            add(double.class);
            add(double[].class);
            add(char.class);
            add(char[].class);
            add(Boolean.class);
            add(Long.class);
            add(Short.class);
            add(Integer.class);
            add(Byte.class);
            add(Float.class);
            add(Double.class);
            add(Character.class);
            add(String.class);
            add(Date.class);
            add(Locale.class);
            add(Class.class);
            add(Enum.class);
        }
    };
    public static final SimpleTypeHolder DEFAULT = new SimpleTypeHolder();

    private volatile Map<Class<?>, Boolean> simpleTypes;

    /**
     * Creates a new {@link SimpleTypeHolder} containing the default types.
     *
     * @see #SimpleTypeHolder(Set, boolean)
     */
    protected SimpleTypeHolder() {
        this(Collections.emptySet(), true);
    }

    /**
     * Creates a new {@link SimpleTypeHolder} to carry the given custom simple types. Registration of default simple types
     * can be deactivated by passing {@literal false} for {@code registerDefaults}.
     *
     * @param customSimpleTypes
     * @param registerDefaults
     */
    public SimpleTypeHolder(Set<? extends Class<?>> customSimpleTypes, boolean registerDefaults) {

        Assert.notNull(customSimpleTypes, "CustomSimpleTypes must not be null!");

        this.simpleTypes = new WeakHashMap<>(customSimpleTypes.size() + DEFAULTS.size());

        register(customSimpleTypes);

        if (registerDefaults) {
            register(DEFAULTS);
        }
    }

    /**
     * Copy constructor to create a new {@link SimpleTypeHolder} that carries the given additional custom simple types.
     *
     * @param customSimpleTypes must not be {@literal null}
     * @param source must not be {@literal null}
     */
    public SimpleTypeHolder(Set<? extends Class<?>> customSimpleTypes, SimpleTypeHolder source) {

        Assert.notNull(customSimpleTypes, "CustomSimpleTypes must not be null!");
        Assert.notNull(source, "SourceTypeHolder must not be null!");

        this.simpleTypes = new WeakHashMap<>(customSimpleTypes.size() + source.simpleTypes.size());

        register(customSimpleTypes);
        registerCachePositives(source.simpleTypes);
    }

    private void registerCachePositives(Map<Class<?>, Boolean> source) {

        for (Entry<Class<?>, Boolean> entry : source.entrySet()) {

            if (!entry.getValue()) {
                continue;
            }

            this.simpleTypes.put(entry.getKey(), true);
        }
    }

    /**
     * Returns whether the given type is considered a simple one.
     *
     * @param type must not be {@literal null}.
     * @return
     */
    public boolean isSimpleType(Class<?> type) {

        Assert.notNull(type, "Type must not be null!");

        Map<Class<?>, Boolean> localSimpleTypes = this.simpleTypes;
        Boolean isSimpleType = localSimpleTypes.get(type);

        if (Object.class.equals(type) || Enum.class.isAssignableFrom(type)) {
            return true;
        }

        if (isSimpleType != null) {
            return isSimpleType;
        }

        String typeName = type.getName();

        if (typeName.startsWith("java.lang") || type.getName().startsWith("java.time")) {
            return true;
        }

        for (Class<?> simpleType : localSimpleTypes.keySet()) {

            if (simpleType.isAssignableFrom(type)) {

                isSimpleType = localSimpleTypes.get(simpleType);
                this.simpleTypes = put(localSimpleTypes, type, isSimpleType);
                return isSimpleType;
            }
        }

        this.simpleTypes = put(localSimpleTypes, type, false);

        return false;
    }

    private void register(Collection<? extends Class<?>> types) {
        types.forEach(customSimpleType -> this.simpleTypes.put(customSimpleType, true));
    }

    private static Map<Class<?>, Boolean> put(Map<Class<?>, Boolean> simpleTypes, Class<?> type,
            boolean isSimpleType) {

        Map<Class<?>, Boolean> copy = new WeakHashMap<>(simpleTypes);
        copy.put(type, isSimpleType);

        return copy;
    }
}