Gson在序列化反序列化中的TypeAdapter

package waf.json.adatpter;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import com.google.gson.TypeAdapter;
import com.google.gson.internal.LinkedTreeMap;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import com.google.gson.stream.JsonWriter;

public class CommonTypeAdapter extends TypeAdapter<Object>
{

    @Override
    public Object read(JsonReader in) throws IOException
    {
        JsonToken token=in.peek();
        switch(token)
        {
        case BEGIN_ARRAY:
            List<Object> list=new ArrayList<Object>();
            in.beginArray();
            while(in.hasNext())
            {
                list.add(read(in));
            }
            in.endArray();
            return list;

        case BEGIN_OBJECT:
            Map<String,Object> map=new LinkedTreeMap<String,Object>();
            in.beginObject();
            while(in.hasNext())
            {
                map.put(in.nextName(),read(in));
            }
            in.endObject();
            return map;

        case STRING:
            return in.nextString();

        case NUMBER:
            /**
             * 改写数字的处理逻辑，将数字值分为整型与浮点型。
             */
            double dbNum=in.nextDouble();

            // 数字超过long的最大值，返回浮点类型
            if(dbNum>Long.MAX_VALUE)
            {
                return dbNum;
            }

            // 判断数字是否为整数值
            long lngNum=(long)dbNum;
            if(dbNum==lngNum)
            {
                return lngNum;
            }
            else
            {
                return dbNum;
            }

        case BOOLEAN:
            return in.nextBoolean();

        case NULL:
            in.nextNull();
            return null;

        default:
            throw new IllegalStateException();
        }
    }

    @Override
    public void write(JsonWriter out,Object value) throws IOException
    {
        // 序列化无需实现
    }

}

package waf.json.adatpter;

import java.lang.reflect.Type;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;

import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;

public class DateTypeAdapter implements JsonDeserializer<Date> /*,JsonSerializer<Date>*/
{

    @Override
    public Date deserialize(JsonElement json,Type typeOfT,JsonDeserializationContext context) throws JsonParseException
    {
        Date date=null;
        DateFormat df=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        try
        {
            date=df.parse(json.getAsString());
        }
        catch(Exception e)
        {
            date=null;
        }
        return date;
    }
    
}

package waf.json.adatpter;

import java.lang.reflect.Type;

import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;


public class IntegerTypeAdapter implements JsonDeserializer<Integer>
{

    @Override
    public Integer deserialize(final JsonElement json,final Type typeOfT,final JsonDeserializationContext context) throws JsonParseException
    {
        if(json.isJsonNull()||json.getAsString().length()==0)
        {
            return null;
        }
        try
        {
            return json.getAsInt();
        }
        catch(NumberFormatException e)
        {
            return null;
        }
    }

}

package waf.json.adatpter;

import java.lang.reflect.Type;

import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;


public class LongTypeAdapter implements JsonDeserializer<Long>
{

    @Override
    public Long deserialize(final JsonElement json,final Type typeOfT,final JsonDeserializationContext context) throws JsonParseException
    {
        if(json.isJsonNull()||json.getAsString().length()==0)
        {
            return null;
        }
        try
        {
            return json.getAsLong();
        }
        catch(NumberFormatException e)
        {
            return null;
        }
    }

}

package waf.json.adatpter;

import java.lang.reflect.Type;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParseException;

public class MapTypeAdapter1 implements JsonDeserializer<Map<String,Object>>
{

    @Override
    public Map<String,Object> deserialize(JsonElement json,Type typeOfT,JsonDeserializationContext context) throws JsonParseException
    {

        Map<String,Object> treeMap=new HashMap<String,Object>();
        JsonObject jsonObject=json.getAsJsonObject();
        Set<Map.Entry<String,JsonElement>> entrySet=jsonObject.entrySet();
        for(Map.Entry<String,JsonElement> entry:entrySet)
        {
            treeMap.put(entry.getKey(),entry.getValue());
        }
        return treeMap;
    }

}