uavstack-master/com.creditease.uav.fastjson/src/main/java/com/alibaba/fastjson/serializer/DoubleSerializer.java
/*
 * Copyright 1999-2018 Alibaba Group.
 *
 * 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 com.alibaba.fastjson.serializer;

import java.io.IOException;
import java.lang.reflect.Type;
import java.text.DecimalFormat;

/**
 * @author wenshao[szujobs@hotmail.com]
 */
public class DoubleSerializer implements ObjectSerializer {

    public final static DoubleSerializer instance      = new DoubleSerializer();

    private DecimalFormat                decimalFormat = null;

    public DoubleSerializer(){

    }

    public DoubleSerializer(DecimalFormat decimalFormat){
        this.decimalFormat = decimalFormat;
    }

    public DoubleSerializer(String decimalFormat){
        this(new DecimalFormat(decimalFormat));
    }

    public void write(JSONSerializer serializer, Object object, Object fieldName, Type fieldType, int features) throws IOException {
        SerializeWriter out = serializer.out;

        if (object == null) {
            out.writeNull(SerializerFeature.WriteNullNumberAsZero);
            return;
        }

        double doubleValue = ((Double) object).doubleValue();

        if (Double.isNaN(doubleValue) //
                || Double.isInfinite(doubleValue)) {
            out.writeNull();
        } else {
            if (decimalFormat == null) {
                out.writeDouble(doubleValue, true);
            } else {
                String doubleText = decimalFormat.format(doubleValue);
                out.write(doubleText);
            }
        }
    }
}
