content: package com.alibaba.fastjson.parser.deserializer;
  
  import java.lang.reflect.ParameterizedType;
  import java.lang.reflect.Type;
  import java.util.AbstractCollection;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.LinkedHashSet;
  
  import com.alibaba.fastjson.JSONException;
  import com.alibaba.fastjson.parser.DefaultJSONParser;
  import com.alibaba.fastjson.parser.JSONToken;
  
  public class CollectionDeserializer implements ObjectDeserializer {
  
      public final static CollectionDeserializer instance = new CollectionDeserializer();
  
      @SuppressWarnings({ "unchecked", "rawtypes" })
      public <T> T deserialze(DefaultJSONParser parser, Type type, Object fieldName) {
          if (parser.getLexer().token() == JSONToken.NULL) {
              parser.getLexer().nextToken(JSONToken.COMMA);
              return null;
          }
  
          Class<?> rawClass = getRawClass(type);
  
          Collection list;
          if (rawClass == AbstractCollection.class) {
              list = new ArrayList();
          } else if (rawClass.isAssignableFrom(HashSet.class)) {
              list = new HashSet();
          } else if (rawClass.isAssignableFrom(LinkedHashSet.class)) {
              list = new LinkedHashSet();
          } else if (rawClass.isAssignableFrom(ArrayList.class)) {
              list = new ArrayList();
          } else {
              try {
                  list = (Collection) rawClass.newInstance();
              } catch (Exception e) {
                  throw new JSONException("create instane error, class " + rawClass.getName());
              }
          }
  
          Type itemType;
          if (type instanceof ParameterizedType) {
              itemType = ((ParameterizedType) type).getActualTypeArguments()[0];
          } else {
              itemType = Object.class;
          }
          parser.parseArray(itemType, list, fieldName);
  
          return (T) list;
      }
  
      public Class<?> getRawClass(Type type) {
  
          if (type instanceof Class<?>) {
              return (Class<?>) type;
          } else if (type instanceof ParameterizedType) {
              return getRawClass(((ParameterizedType) type).getRawType());
          } else {
              throw new JSONException("TODO");
          }
      }
  
      public int getFastMatchToken() {
          return JSONToken.LBRACKET;
      }
  }
  