content: package com.alibaba.fastjson.serializer;
  
  import java.io.IOException;
  import java.lang.reflect.ParameterizedType;
  import java.lang.reflect.Type;
  import java.util.Enumeration;
  
  
  public class EnumerationSeriliazer implements ObjectSerializer {
      public static EnumerationSeriliazer instance = new EnumerationSeriliazer();
      
      public void write(JSONSerializer serializer, Object object, Object fieldName, Type fieldType) throws IOException {
          SerializeWriter out = serializer.getWriter();
  
          if (object == null) {
              if (out.isEnabled(SerializerFeature.WriteNullListAsEmpty)) {
                  out.write("[]");
              } else {
                  out.writeNull();
              }
              return;
          }
          
          Type elementType = null;
          if (serializer.isEnabled(SerializerFeature.WriteClassName)) {
              if (fieldType instanceof ParameterizedType) {
                  ParameterizedType param = (ParameterizedType) fieldType;
                  elementType = param.getActualTypeArguments()[0];
              }
          }
          
          Enumeration<?> e = (Enumeration<?>) object;
          
          SerialContext context = serializer.getContext();
          serializer.setContext(context, object, fieldName);
  
          try {
              int i = 0;
              out.append('[');
              while (e.hasMoreElements()) {
                  Object item = e.nextElement();
                  if (i++ != 0) {
                      out.append(',');
                  }
  
                  if (item == null) {
                      out.writeNull();
                      continue;
                  }
  
                  Class<?> clazz = item.getClass();
  
                  if (clazz == Integer.class) {
                      out.writeInt(((Integer) item).intValue());
                      continue;
                  }
  
                  if (clazz == Long.class) {
                      out.writeLong(((Long) item).longValue());
  
                      if (out.isEnabled(SerializerFeature.WriteClassName)) {
                          out.write('L');
                      }
                      continue;
                  }
  
                  ObjectSerializer itemSerializer = serializer.getObjectWriter(clazz);
                  itemSerializer.write(serializer, item, i - 1, elementType);
              }
              out.append(']');
          } finally {
              serializer.setContext(context);
          }
      }
  }
  