Gson反序列化自定义,防止为空

1. 现在一般都是用Retrofit 封装okhttp的请求框架
   需要添加GsonConverterFactory.create(gson),
   而有时候gson中一些字段可能为null
   数组可能为空 而可能产生bug引起程序崩溃

Gson gson = new GsonBuilder()
.registerTypeAdapter(
List.class,new MyListAdapter())//可添加N个typeAdapter根据业务需要
 .registerTypeAdapter(
String.class,new MyStringAdapter()).create();

        retrofit = new Retrofit.Builder()
                .baseUrl(baseUri)     //Set the Api Base URL
                .client(okHttpClient) //The HTTP client used for requests.
                .addConverterFactory(
GsonConverterFactory.create(gson))
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                .build();

2.数组适配器

package xxx.typeadapter;
import com.google.gson.Gson;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;
import com.google.gson.JsonPrimitive;
import com.google.gson.JsonSerializationContext;
import com.google.gson.JsonSerializer;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;

public class MyListAdapter<T> implements JsonSerializer<List<?>>, JsonDeserializer {
    @Override
    public JsonElement serialize(List<?> src, Type typeOfSrc, JsonSerializationContext context) {
        return new JsonPrimitive(new Gson().toJson(src));

    }

    @Override
    public Object deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
        try {
            if (json.getAsJsonArray() == null) {//定义为JsonArray类型
                return new ArrayList<>();
            }
        } catch (Exception ignore) {
        }
        try {
            return new Gson().fromJson(json, typeOfT);
        } catch (NumberFormatException e) {
            return new ArrayList<>();
        }
    }
}

3.String适配器

package com.zhisheng.modulenetwork.typeadapter;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;
import com.google.gson.JsonPrimitive;
import com.google.gson.JsonSerializationContext;
import com.google.gson.JsonSerializer;
import java.lang.reflect.Type;

public class MyStringAdapter implements JsonSerializer<String>, JsonDeserializer<String> {
    @Override
    public String deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
            throws JsonParseException {
        try {
            if (json.getAsString().equals("") || json.getAsString().equals("null")) {//定义为long类型,如果后台返回""或者null,则返回0
                return "";
            }
        } catch (Exception ignore) {
        }
        try {
            return json.getAsString();
        } catch (NumberFormatException e) {
            return "";
        }
    }

    @Override
    public JsonElement serialize(String src, Type typeOfSrc, JsonSerializationContext context) {
        return new JsonPrimitive (src);
    }
}

4.比如boolean 类型 int类型 Long类型等等可自己实现