通过您提供的链接可访问的当前JSON响应似乎存在一些设计问题或怀疑。我将在此处发布JSON，以免将来丢失它：
{ "weather": { "forecast3hours": [ { "grid": { "city": "충북", "county": "충주시", "village": "목행동", "latitude": "37.0135600000", "longitude": "127.9036500000" }, "lightning1hour": "0", "timeRelease": "2017-02-24 16:30:00", "wind": { "wspd2hour": "3.10", "wdir1hour": "179.00", "wspd1hour": "4.20", "wdir2hour": "176.00", "wdir3hour": "", "wspd3hour": "", "wdir4hour": "", "wspd4hour": "" }, "precipitation": { "sinceOntime1hour": "0.00", "type1hour": "0", "sinceOntime2hour": "0.00", "type2hour": "0", "sinceOntime3hour": "", "type3hour": "", "sinceOntime4hour": "", "type4hour": "" }, "sky": { "pre1hour": "SKY_V01", "name1hour": "맑음", "pre2hour": "SKY_V01", "name2hour": "맑음", "pre3hour": "", "name3hour": "", "pre4hour": "", "name4hour": "" }, "temperature": { "temp1hour": "3.20", "temp2hour": "2.00", "temp3hour": "", "temp4hour": "" }, "humidity": { "rh1hour": "41.00", "rh2hour": "50.00", "rh3hour": "", "rh4hour": "" }, "lightning2hour": "0", "lightning3hour": "", "lightning4hour": "" } ] }, "common": { "alertYn": "N", "stormYn": "N" }, "result": { "pre": 9200, "requestUrl": "/weather/forecast/3hours?lon=127.9259&lat=36.991&version=1&appKey=4ce0462a-3884-30ab-ab13-93efb1bc171f", "message": "성공" }}从我的角度来看，它们是：
- 没有数组，而是人为索引的对象键（这是您的问题的主题）。
- 空字符串表示可能的
null
值，而不是null
s或仅将其排除在响应之外。 - 几乎所有的值都表示为字符串文字，即使它们似乎是非字符串也是如此。
- 布尔值似乎用
Yn
后缀标记，分别定义true
和false
使用"Y"
和"N"
。
这就是为什么自动POJO生成器可能不是最佳的处理方式，因为它们可能无法检测到特定JSON字符串值的“真实”类型，而且它们无法生成自定义反序列化器。不知道为什么要这样设计，但是您可以设计自定义映射，使其对程序更加友好，并且可以对其进行更多控制。
final class Response { final Weather weather = null; final Common common = null; final Result result = null; @Override public String toString() { return new StringBuilder("Response{") .append("weather=").append(weather) .append(", common=").append(common) .append(", result=").append(result) .append('}').toString(); }}final class Weather { final List<Forecast> forecast3hours = null; @Override public String toString() { return new StringBuilder("Weather{") .append("forecast3hours=").append(forecast3hours) .append('}').toString(); }}final class Forecast { final Grid grid; final Date timeRelease; final List<Integer> lightnings; final List<Wind> winds; final List<Precipitation> precipitations; final List<Sky> skies; final List<Float> temperatures; final List<Float> humidities; Forecast(final Grid grid, final Date timeRelease, final List<Integer> lightnings, final List<Wind> winds, final List<Precipitation> precipitations, final List<Sky> skies, final List<Float> temperatures, final List<Float> humidities) { this.grid = grid; this.timeRelease = timeRelease; this.lightnings = lightnings; this.winds = winds; this.precipitations = precipitations; this.skies = skies; this.temperatures = temperatures; this.humidities = humidities; } @Override public String toString() { return new StringBuilder("Forecast{") .append("grid=").append(grid) .append(", timeRelease=").append(timeRelease) .append(", lightnings=").append(lightnings) .append(", winds=").append(winds) .append(", precipitations=").append(precipitations) .append(", skies=").append(skies) .append(", temperatures=").append(temperatures) .append(", humidities=").append(humidities) .append('}').toString(); }}final class Grid { final String city = null; final String county = null; final String village = null; final double latitude = Double.valueOf(0); // disable inlining the primitive double 0 final double longitude = Double.valueOf(0); // disable inlining the primitive double 0 @Override public String toString() { return new StringBuilder("Grid{") .append("city='").append(city).append(''') .append(", county='").append(county).append(''') .append(", village='").append(village).append(''') .append(", latitude=").append(latitude) .append(", longitude=").append(longitude) .append('}').toString(); }}final class Wind { final float speed; final float direction; Wind(final float speed, final float direction) { this.speed = speed; this.direction = direction; } @Override public String toString() { return new StringBuilder("Wind{") .append("speed=").append(speed) .append(", direction=").append(direction) .append('}').toString(); }}final class Precipitation { final float sinceOntime; final int type; Precipitation(final float sinceOntime, final int type) { this.sinceontime = sinceOntime; this.type = type; } @Override public String toString() { return new StringBuilder("Precipitation{") .append("sinceontime='").append(sinceOntime).append(''') .append(", type=").append(type) .append('}').toString(); }}final class Sky { final String pre; final String name; Sky(final String pre, final String name) { this.pre = pre; this.name = name; } @Override public String toString() { return new StringBuilder("Sky{") .append("pre='").append(pre).append(''') .append(", name='").append(name).append(''') .append('}').toString(); }}final class Common { @SerializedName("alertYn") @JsonAdapter(YnToBooleanJsonDeserializer.class) final boolean alert = Boolean.valueOf(false); // disable inlining the primitive boolean false @SerializedName("stormYn") @JsonAdapter(YnToBooleanJsonDeserializer.class) final boolean storm = Boolean.valueOf(false); // disable inlining the primitive boolean false @Override public String toString() { return new StringBuilder("Common{") .append("alert=").append(alert) .append(", storm=").append(storm) .append('}').toString(); }}final class Result { final int pre = Integer.valueOf(0); // disable inlining the primitive int 0 final String requestUrl = null; final String message = null; @Override public String toString() { return new StringBuilder("Result{") .append("pre=").append(pre) .append(", requestUrl='").append(requestUrl).append(''') .append(", message='").append(message).append(''') .append('}').toString(); }}其中一些映射具有显式构造函数-
必须在自定义反序列化器中手动实例化此类对象。如果没有提供构造函数，那么Gson可以处理这种映射本身，而该映射只具有有关应如何反序列化特定对象的足够信息。
由于应该以非标准方式解析数据，因此可以实现几个自定义反序列化器。以下类型适配器分别将
"Y"和转换
"N"为
true和
false。
final class YnToBooleanJsonDeserializer implements JsonDeserializer<Boolean> { // Gson will instantiate this adapter itself private YnToBooleanJsonDeserializer() { } @Override public Boolean deserialize(final JsonElement jsonElement, final Type type, final JsonDeserializationContext context) throws JsonParseException { final String rawFlag = jsonElement.getAsString(); switch ( rawFlag ) { case "N": return false; case "Y": return true; default: throw new JsonParseException("Can't parse: " + rawFlag); } }}下一个
JsonDeserializer尝试
xxx<N>hour使用正则表达式检测类似键，并提取
<N>索引以构建构造
Forecast实例所需的列表。请注意，它可以解析任意大小的“列表”（JSON中的列表）。
final class ForecastJsonDeserializer implements JsonDeserializer<Forecast> { // This deserializer does not hold any state and can be instantiated once per application life-cycle. private static final JsonDeserializer<Forecast> forecastJsonDeserializer = new ForecastJsonDeserializer(); private ForecastJsonDeserializer() { } static JsonDeserializer<Forecast> getForecastJsonDeserializer() { return forecastJsonDeserializer; } @Override public Forecast deserialize(final JsonElement jsonElement, final Type type, final JsonDeserializationContext context) throws JsonParseException { final JsonObject jsonObject = jsonElement.getAsJsonObject(); return new Forecast( context.deserialize(jsonObject.get("grid"), Grid.class), context.deserialize(jsonObject.get("timeRelease"), Date.class), lightningsExtractor.parseList(jsonObject), windsExtractor.parseList(jsonObject.get("wind").getAsJsonObject()), precipitationsExtractor.parseList(jsonObject.get("precipitation").getAsJsonObject()), skiesExtractor.parseList(jsonObject.get("sky").getAsJsonObject()), temperaturesExtractor.parseList(jsonObject.get("temperature").getAsJsonObject()), humiditiesExtractor.parseList(jsonObject.get("humidity").getAsJsonObject()) ); } private static final AbstractExtractor<Integer> lightningsExtractor = new AbstractExtractor<Integer>(compile("lightning(\d)hour")) { @Override protected Integer parse(final int index, final JsonObject jsonObject) { final String rawLightning = jsonObject.get("lightning" + index + "hour").getAsString(); if ( rawLightning.isEmpty() ) { return null; } return parseInt(rawLightning); } }; private static final AbstractExtractor<Wind> windsExtractor = new AbstractExtractor<Wind>(compile("(?:wdir|wspd)(\d)hour")) { @Override protected Wind parse(final int index, final JsonObject jsonObject) { String rawSpeed = jsonObject.get("wspd" + index + "hour").getAsString(); String rawDirection = jsonObject.get("wdir" + index + "hour").getAsString(); if ( rawSpeed.isEmpty() && rawDirection.isEmpty() ) { return null; } return new Wind(parseFloat(rawSpeed), parseFloat(rawDirection)); } }; private static final AbstractExtractor<Precipitation> precipitationsExtractor = new AbstractExtractor<Precipitation>(compile("(?:sinceontime|type)(\d)hour")) { @Override protected Precipitation parse(final int index, final JsonObject jsonObject) { final String rawSinceontime = jsonObject.get("sinceOntime" + index + "hour").getAsString(); final String rawType = jsonObject.get("type" + index + "hour").getAsString(); if ( rawSinceOntime.isEmpty() && rawType.isEmpty() ) { return null; } return new Precipitation(parseFloat(rawSinceOntime), parseInt(rawType)); } }; private static final AbstractExtractor<Sky> skiesExtractor = new AbstractExtractor<Sky>(compile("(?:pre|name)(\d)hour")) { @Override protected Sky parse(final int index, final JsonObject jsonObject) { final String rawCode = jsonObject.get("pre" + index + "hour").getAsString(); final String rawName = jsonObject.get("name" + index + "hour").getAsString(); if ( rawCode.isEmpty() && rawName.isEmpty() ) { return null; } return new Sky(rawCode, rawName); } }; private static final AbstractExtractor<Float> temperaturesExtractor = new AbstractExtractor<Float>(compile("temp(\d)hour")) { @Override protected Float parse(final int index, final JsonObject jsonObject) { final String rawTemperature = jsonObject.get("temp" + index + "hour").getAsString(); if ( rawTemperature.isEmpty() ) { return null; } return parseFloat(rawTemperature); } }; private static final AbstractExtractor<Float> humiditiesExtractor = new AbstractExtractor<Float>(compile("rh(\d)hour")) { @Override protected Float parse(final int index, final JsonObject jsonObject) { final String rawHumidity = jsonObject.get("rh" + index + "hour").getAsString(); if ( rawHumidity.isEmpty() ) { return null; } return parseFloat(rawHumidity); } }; private abstract static class AbstractExtractor<T> { private final Pattern pattern; private AbstractExtractor(final Pattern pattern) { this.pattern = pattern; } protected abstract T parse(int index, JsonObject jsonObject); private List<T> parseList(final JsonObject jsonObject) { final List<T> list = new ArrayList<>(); for ( final Entry<String, JsonElement> e : jsonObject.entrySet() ) { final String key = e.getKey(); final Matcher matcher = pattern.matcher(key); // Check if the given regular expression matches the key if ( matcher.matches() ) { // If yes, then just extract and parse the index final int index = parseInt(matcher.group(1)); // And check if there is enough room in the result list because the JSON response may contain unordered keys while ( index > list.size() ) { list.add(null); } // As Java lists are 0-based if ( list.get(index - 1) == null ) { // Assuming that null marks an object that's probably not parsed yet list.set(index - 1, parse(index, jsonObject)); } } } return list; } }}现在可以将它们放在一起：
public static void main(final String... args) { final Gson gson = new GsonBuilder() .setDateFormat("yyyy-MM-dd hh:mm:ss") .registerTypeAdapter(Forecast.class, getForecastJsonDeserializer()) .create(); final Response response = gson.fromJson(JSON, Response.class); System.out.println(response);}输出：
响应{天气=天气{forecast3hours = [预测{grid = Grid {city =’충북’，县=’충주시’，村庄=’목행동’，纬度=
37.01356，经度= 127.90365}}，timeRelease =周五2月24日30:30 ：00 EET 2017，闪电=
[0，0，null，null]，风= [风{speed = 4.2，方向= 179.0}，风{speed = 3.1，方向=
176.0}，null，null]，降水量= [降水{sinceontime =‘0.0’，类型= 0}，降水{sinceOntime
=‘0.0’，类型= 0}，null，null]，天空= [Sky {pre =’SKY_V01’，name =’맑음’}，Sky {pre
=’SKY_V01’，name =’맑음’}，null，null]，温度= [3.2，2.0，null，null]，湿度=
[41.0，50.0，null，null]}]}，common = Common { alert = false，storm =
false}，result = Result {pre = 9200，requestUrl =’/ weather / forecast /
3hours？lon = 127.9259＆lat = 36.991＆version = 1＆appKey = 4ce0462a-3884-30ab-
ab13-93efb1bc171f’，message =’성공’}}
