com.getperka.flatpack.codexes.NumberCodex.java Source code

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Here is the source code for com.getperka.flatpack.codexes.NumberCodex.java

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/*
 * #%L
 * FlatPack serialization code
 * %%
 * Copyright (C) 2012 Perka Inc.
 * %%
 * 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.
 * #L%
 */
package com.getperka.flatpack.codexes;

import java.io.IOException;
import java.math.BigDecimal;
import java.math.BigInteger;

import javax.inject.Inject;

import com.getperka.flatpack.ext.DeserializationContext;
import com.getperka.flatpack.ext.JsonKind;
import com.getperka.flatpack.ext.SerializationContext;
import com.getperka.flatpack.ext.Type;
import com.getperka.flatpack.ext.TypeHint;
import com.google.gson.JsonElement;
import com.google.inject.TypeLiteral;

/**
 * Primitive numberic support.
 *
 * @param <N> the boxed Number type
 */
public class NumberCodex<N extends Number> extends ValueCodex<N> {
    private Class<N> clazz;

    @Inject
    protected NumberCodex() {
    }

    @Override
    public Type describe() {
        Type.Builder builder = new Type.Builder();
        if (BigDecimal.class.equals(clazz) || BigInteger.class.equals(clazz)) {
            // Accepts strings or numbers
            builder.withJsonKind(JsonKind.ANY);
        } else if (Float.class.equals(clazz) || Double.class.equals(clazz)) {
            builder.withJsonKind(JsonKind.DOUBLE);
        } else {
            builder.withJsonKind(JsonKind.INTEGER);
        }
        return builder.withTypeHint(TypeHint.create(clazz)).build();
    }

    /**
     * Returns {@code true} for {@code null} or {@code 0} values.
     */
    @Override
    public boolean isDefaultValue(N value) {
        if (value == null) {
            return true;
        }
        if (BigDecimal.class.equals(clazz)) {
            return BigDecimal.ZERO.compareTo((BigDecimal) value) == 0;
        }
        if (BigInteger.class.equals(clazz)) {
            return BigInteger.ZERO.compareTo((BigInteger) value) == 0;
        }
        if (Float.class.equals(clazz) || Double.class.equals(clazz)) {
            return value.doubleValue() == 0.0;
        }
        return value.intValue() == 0;
    }

    @Override
    public N readNotNull(JsonElement element, DeserializationContext context) {
        Object toReturn;
        if (BigDecimal.class.equals(clazz)) {
            toReturn = element.getAsBigDecimal();
        } else if (BigInteger.class.equals(clazz)) {
            toReturn = element.getAsBigInteger();
        } else if (Byte.class.equals(clazz)) {
            toReturn = element.getAsByte();
        } else if (Double.class.equals(clazz)) {
            toReturn = element.getAsDouble();
        } else if (Float.class.equals(clazz)) {
            toReturn = element.getAsFloat();
        } else if (Integer.class.equals(clazz)) {
            toReturn = element.getAsInt();
        } else if (Long.class.equals(clazz)) {
            toReturn = element.getAsLong();
        } else if (Short.class.equals(clazz)) {
            toReturn = element.getAsShort();
        } else {
            throw new UnsupportedOperationException("Unimplemented Number type " + clazz.getName());
        }
        return clazz.cast(toReturn);
    }

    @Override
    public void writeNotNull(N object, SerializationContext context) throws IOException {
        if (BigDecimal.class.equals(clazz) || BigInteger.class.equals(clazz)) {
            context.getWriter().value(object.toString());
        } else {
            context.getWriter().value(object);
        }
    }

    @Inject
    @SuppressWarnings("unchecked")
    void inject(TypeLiteral<N> type) {
        this.clazz = (Class<N>) type.getRawType();
    }
}