content: /*
   * 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);
              }
          }
      }
  }
  