org.chaston.oakfunds.storage.EnumIdentifiableSource.java Source code

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Here is the source code for org.chaston.oakfunds.storage.EnumIdentifiableSource.java

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/*
 * Copyright 2014 Miles Chaston
 *
 * 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.chaston.oakfunds.storage;

import com.google.common.collect.ImmutableMap;

import java.util.EnumSet;

/**
 * TODO(mchaston): write JavaDocs
 */
public class EnumIdentifiableSource<E extends Enum & Identifiable> implements IdentifiableSource<E> {

    private final Class<E> enumClass;
    private final ImmutableMap<Byte, E> valuesByIdentifier;
    private final ImmutableMap<String, E> valuesByJson;

    public EnumIdentifiableSource(Class<E> enumClass) {
        this.enumClass = enumClass;
        ImmutableMap.Builder<Byte, E> valuesByIdentifierBuilder = ImmutableMap.builder();
        ImmutableMap.Builder<String, E> valuesByJsonBuilder = ImmutableMap.builder();
        EnumSet<? extends E> enumSet = EnumSet.allOf(enumClass);
        for (E enumValue : enumSet) {
            valuesByIdentifierBuilder.put(enumValue.identifier(), enumValue);
            valuesByJsonBuilder.put(enumValue.toJson(), enumValue);
        }
        valuesByIdentifier = valuesByIdentifierBuilder.build();
        valuesByJson = valuesByJsonBuilder.build();
    }

    @Override
    public E lookup(byte identifier) {
        E identifiable = valuesByIdentifier.get(identifier);
        if (identifiable != null) {
            return identifiable;
        }
        throw new IllegalArgumentException("No such " + enumClass.getSimpleName() + " identifier: " + identifier);
    }

    @Override
    public E fromJson(String json) {
        E identifiable = valuesByJson.get(json);
        if (identifiable != null) {
            return identifiable;
        }
        throw new IllegalArgumentException("No such " + enumClass.getSimpleName() + " json value: " + json);
    }

    @Override
    public String getTypeName() {
        return enumClass.getSimpleName();
    }
}