org.prebake.util.ObjUtil.java Source code

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Here is the source code for org.prebake.util.ObjUtil.java

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// Copyright 2010, Mike Samuel
//
// 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.prebake.util;

import com.google.common.collect.ImmutableCollection;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;

import java.lang.reflect.Array;
import java.util.Map;
import java.util.Set;

import javax.annotation.Nullable;
import javax.annotation.ParametersAreNonnullByDefault;

/**
 * Utilities for dealing with object graphs.
 *
 * @author Mike Samuel <mikesamuel@gmail.com>
 */
@ParametersAreNonnullByDefault
public final class ObjUtil {
    private static final Set<Class<?>> IMMUTABLE_CLASSES = ImmutableSet.<Class<?>>builder().add(String.class)
            .add(Integer.class).add(Void.class).add(Byte.class).add(Short.class).add(Long.class).add(Float.class)
            .add(Boolean.class).add(Character.class).add(Double.class).build();

    public static boolean isDeeplyImmutable(@Nullable Object o) {
        if (o == null) {
            return true;
        }
        if (IMMUTABLE_CLASSES.contains(o.getClass())) {
            return true;
        }
        if (o instanceof ImmutableCollection<?>) {
            return isDeeplyImmutable((ImmutableCollection<?>) o);
        }
        if (o instanceof ImmutableMap<?, ?>) {
            return isDeeplyImmutable((ImmutableMap<?, ?>) o);
        }
        if (o.getClass().isArray() && Array.getLength(o) == 0) {
            return true;
        }
        return false;
    }

    public static boolean isDeeplyImmutable(ImmutableMap<?, ?> m) {
        for (Map.Entry<?, ?> e : m.entrySet()) {
            if (!(isDeeplyImmutable(e.getKey()) && isDeeplyImmutable(e.getValue()))) {
                return false;
            }
        }
        return true;
    }

    public static boolean isDeeplyImmutable(ImmutableCollection<?> c) {
        for (Object o : c) {
            if (!isDeeplyImmutable(o)) {
                return false;
            }
        }
        return true;
    }

    private ObjUtil() {
        /* not instantiable */ }
}