参考自李德涛博客

1.重写TypeAdapter

package techscan.tsbarcode.utils;

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;

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

public class MapTypeAdapter 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
    }
}

2.使用

        String json = "{\n" +
                "  \"z\": 100,\n" +
                "  \"x\": 200,\n" +
                "  \"c\": 300,\n" +
                "  \"v\":\"中文\",\n" +
                "  \"b\":true\n" +
                "}";
        Gson gson = new GsonBuilder()
                .registerTypeAdapter(new TypeToken<Map<String, Object>>() {
                }.getType(), new MapTypeAdapter()).create();
        Map<String, Object> map = gson.fromJson(json, new TypeToken<Map<String, Object>>() {
        }.getType());