org.immutables.fixture.encoding.defs.OptionalMap.java Source code

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Here is the source code for org.immutables.fixture.encoding.defs.OptionalMap.java

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/*
   Copyright 2016 Immutables Authors and Contributors
    
   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.immutables.fixture.encoding.defs;

import java.util.Optional;
import com.google.common.collect.ImmutableMap;
import java.util.Map;
import javax.annotation.Nullable;
import org.immutables.encode.Encoding;

@Encoding
class OptionalMap<K, V> {

    // implemented as nullable map field
    @Encoding.Impl
    private final ImmutableMap<K, V> map = null;

    // Expose (and detect) the field as Optional of Map
    @Encoding.Expose
    public Optional<Map<K, V>> get() {
        return Optional.<Map<K, V>>ofNullable(map);
    }

    // alternatively it can be exposed as Optional of ImmutableMap
    @Encoding.Expose
    public Optional<ImmutableMap<K, V>> getImmutable() {
        return Optional.ofNullable(map);
    }

    // as field is nullable, so null-safe hashcode required
    @Override
    public int hashCode() {
        return java.util.Objects.hashCode(map);
    }

    @Override
    public String toString() {
        return get().toString();
    }

    boolean equals(OptionalMap<K, V> obj) {
        return java.util.Objects.equals(this.map, obj.map);
    }

    @Encoding.Of
    static @Nullable <K, V> ImmutableMap<K, V> init(Optional<? extends Map<K, V>> map) {
        return map.isPresent() ? ImmutableMap.copyOf(map.get()) : null;
    }

    @Encoding.Builder
    static class Builder<K, V> {
        private @Nullable ImmutableMap.Builder<K, V> builder = null;

        @Encoding.Naming("put*")
        @Encoding.Init
        void put(K row, V value) {
            nonnullBuilder().put(row, value);
        }

        @Encoding.Naming("putAll*")
        @Encoding.Init
        void putAll(Map<? extends K, ? extends V> entries) {
            nonnullBuilder().putAll(entries);
        }

        @Encoding.Naming("set*")
        @Encoding.Init
        @Encoding.Copy
        void set(Optional<? extends Map<K, V>> entries) {
            this.builder = null;
            if (entries.isPresent()) {
                nonnullBuilder().putAll(entries.get());
            }
        }

        private ImmutableMap.Builder<K, V> nonnullBuilder() {
            return builder == null ? builder = ImmutableMap.<K, V>builder() : builder;
        }

        @Encoding.Build
        @Nullable
        ImmutableMap<K, V> build() {
            return builder != null ? builder.build() : null;
        }
    }
}