我有以下json：
[
{
"name": "Australia",
"topLevelDomain": [
".au"
],
"alpha2Code": "AU",
"alpha3Code": "AUS",
"callingCodes": [
"61"
],
"capital": "Canberra",
"altSpellings": [
"AU"
],
"region": "Oceania",
"subregion": "Australia and New Zealand",
"population": 24117360,
"latlng": [
-27.0,
133.0
],
"demonym": "Australian",
"area": 7692024.0,
"gini": 30.5,
"timezones": [
"UTC+05:00",
"UTC+06:30",
"UTC+07:00",
"UTC+08:00",
"UTC+09:30",
"UTC+10:00",
"UTC+10:30",
"UTC+11:30"
],
"borders": [],
"nativeName": "Australia",
"numericCode": "036",
"currencies": [
{
"code": "AUD",
"name": "Australian dollar",
"symbol": "$"
}
],
"languages": [
{
"iso639_1": "en",
"iso639_2": "eng",
"name": "English",
"nativeName": "English"
}
],
"translations": {
"de": "Australien",
"es": "Australia",
"fr": "Australie",
"ja": "オーストラリア",
"it": "Australia",
"br": "Austrália",
"pt": "Austrália",
"nl": "Australië",
"hr": "Australija",
"fa": "استرالیا"
},
"flag": "https://restcountries.eu/data/aus.svg",
"regionalBlocs": [],
"cioc": "AUS"
},
{
"name": "Brazil",
"topLevelDomain": [
".br"
],
"alpha2Code": "BR",
"alpha3Code": "BRA",
"callingCodes": [
"55"
],
"capital": "Brasília",
"altSpellings": [
"BR",
"Brasil",
"Federative Republic of Brazil",
"República Federativa do Brasil"
],
"region": "Americas",
"subregion": "South America",
"population": 206135893,
"latlng": [
-10.0,
-55.0
],
"demonym": "Brazilian",
"area": 8515767.0,
"gini": 54.7,
"timezones": [
"UTC-05:00",
"UTC-04:00",
"UTC-03:00",
"UTC-02:00"
],
"borders": [
"ARG",
"BOL",
"COL",
"GUF",
"GUY",
"PRY",
"PER",
"SUR",
"URY",
"VEN"
],
"nativeName": "Brasil",
"numericCode": "076",
"currencies": [
{
"code": "BRL",
"name": "Brazilian real",
"symbol": "R$"
}
],
"languages": [
{
"iso639_1": "pt",
"iso639_2": "por",
"name": "Portuguese",
"nativeName": "Português"
}
],
"translations": {
"de": "Brasilien",
"es": "Brasil",
"fr": "Brésil",
"ja": "ブラジル",
"it": "Brasile",
"br": "Brasil",
"pt": "Brasil",
"nl": "Brazilië",
"hr": "Brazil",
"fa": "برزیل"
},
"flag": "https://restcountries.eu/data/bra.svg",
"regionalBlocs": [
{
"acronym": "USAN",
"name": "Union of South American Nations",
"otherAcronyms": [
"UNASUR",
"UNASUL",
"UZAN"
],
"otherNames": [
"Unión de Naciones Suramericanas",
"União de Nações Sul-Americanas",
"Unie van Zuid-Amerikaanse Naties",
"South American Union"
]
}
],
"cioc": "BRA"
},
{
"name": "China",
"topLevelDomain": [
".cn"
],
"alpha2Code": "CN",
"alpha3Code": "CHN",
"callingCodes": [
"86"
],
"capital": "Beijing",
"altSpellings": [
"CN",
"Zhōngguó",
"Zhongguo",
"Zhonghua",
"People's Republic of China",
"中华人民共和国",
"Zhōnghuá Rénmín Gònghéguó"
],
"region": "Asia",
"subregion": "Eastern Asia",
"population": 1377422166,
"latlng": [
35.0,
105.0
],
"demonym": "Chinese",
"area": 9640011.0,
"gini": 47.0,
"timezones": [
"UTC+08:00"
],
"borders": [
"AFG",
"BTN",
"MMR",
"HKG",
"IND",
"KAZ",
"PRK",
"KGZ",
"LAO",
"MAC",
"MNG",
"PAK",
"RUS",
"TJK",
"VNM"
],
"nativeName": "中国",
"numericCode": "156",
"currencies": [
{
"code": "CNY",
"name": "Chinese yuan",
"symbol": "¥"
}
],
"languages": [
{
"iso639_1": "zh",
"iso639_2": "zho",
"name": "Chinese",
"nativeName": "中文 (Zhōngwén)"
}
],
"translations": {
"de": "China",
"es": "China",
"fr": "Chine",
"ja": "中国",
"it": "Cina",
"br": "China",
"pt": "China",
"nl": "China",
"hr": "Kina",
"fa": "چین"
},
"flag": "https://restcountries.eu/data/chn.svg",
"regionalBlocs": [],
"cioc": "CHN"
},
{
"name": "United Kingdom of Great Britain and Northern Ireland",
"topLevelDomain": [
".uk"
],
"alpha2Code": "GB",
"alpha3Code": "GBR",
"callingCodes": [
"44"
],
"capital": "London",
"altSpellings": [
"GB",
"UK",
"Great Britain"
],
"region": "Europe",
"subregion": "Northern Europe",
"population": 65110000,
"latlng": [
54.0,
-2.0
],
"demonym": "British",
"area": 242900.0,
"gini": 34.0,
"timezones": [
"UTC-08:00",
"UTC-05:00",
"UTC-04:00",
"UTC-03:00",
"UTC-02:00",
"UTC",
"UTC+01:00",
"UTC+02:00",
"UTC+06:00"
],
"borders": [
"IRL"
],
"nativeName": "United Kingdom",
"numericCode": "826",
"currencies": [
{
"code": "GBP",
"name": "British pound",
"symbol": "£"
}
],
"languages": [
{
"iso639_1": "en",
"iso639_2": "eng",
"name": "English",
"nativeName": "English"
}
],
"translations": {
"de": "Vereinigtes Königreich",
"es": "Reino Unido",
"fr": "Royaume-Uni",
"ja": "イギリス",
"it": "Regno Unito",
"br": "Reino Unido",
"pt": "Reino Unido",
"nl": "Verenigd Koninkrijk",
"hr": "Ujedinjeno Kraljevstvo",
"fa": "بریتانیای کبیر و ایرلند شمالی"
},
"flag": "https://restcountries.eu/data/gbr.svg",
"regionalBlocs": [
{
"acronym": "EU",
"name": "European Union",
"otherAcronyms": [],
"otherNames": []
}
],
"cioc": "GBR"
},
{
"name": "United States of America",
"topLevelDomain": [
".us"
],
"alpha2Code": "US",
"alpha3Code": "USA",
"callingCodes": [
"1"
],
"capital": "Washington, D.C.",
"altSpellings": [
"US",
"USA",
"United States of America"
],
"region": "Americas",
"subregion": "Northern America",
"population": 323947000,
"latlng": [
38.0,
-97.0
],
"demonym": "American",
"area": 9629091.0,
"gini": 48.0,
"timezones": [
"UTC-12:00",
"UTC-11:00",
"UTC-10:00",
"UTC-09:00",
"UTC-08:00",
"UTC-07:00",
"UTC-06:00",
"UTC-05:00",
"UTC-04:00",
"UTC+10:00",
"UTC+12:00"
],
"borders": [
"CAN",
"MEX"
],
"nativeName": "United States",
"numericCode": "840",
"currencies": [
{
"code": "USD",
"name": "United States dollar",
"symbol": "$"
}
],
"languages": [
{
"iso639_1": "en",
"iso639_2": "eng",
"name": "English",
"nativeName": "English"
}
],
"translations": {
"de": "Vereinigte Staaten von Amerika",
"es": "Estados Unidos",
"fr": "États-Unis",
"ja": "アメリカ合衆国",
"it": "Stati Uniti D'America",
"br": "Estados Unidos",
"pt": "Estados Unidos",
"nl": "Verenigde Staten",
"hr": "Sjedinjene Američke Države",
"fa": "ایالات متحده آمریکا"
},
"flag": "https://restcountries.eu/data/usa.svg",
"regionalBlocs": [
{
"acronym": "NAFTA",
"name": "North American Free Trade Agreement",
"otherAcronyms": [],
"otherNames": [
"Tratado de Libre Comercio de América del Norte",
"Accord de Libre-échange Nord-Américain"
]
}
],
"cioc": "USA"
}
]
我能够将JSON中的第一个对象完全反序列化为模型，其中将名称，topLevelDomain等属性映射到模型Java对象Country的属性。使用以下代码的对象：
// json arg is the complete json mentioned above
private Country jsonToCountry(String json){
Country country = null;
ObjectMapper mapper = new ObjectMapper();
try {
json = json.substring(1,json.length()-2);
country = mapper.readValue(json, Country.class);
} catch (IOException e) {
e.printStackTrace();
}
return country;
}
我必须去掉后括号才能使其正常工作。但是，此方法仅反序列化第一个对象。我想获得一个Country对象的列表，并尝试像这样实现它：
private List<Country> jsonToCountry(String json){
List<Country> countryList = null;
ObjectMapper mapper = new ObjectMapper();
try {
json = (json.indexOf("[") == 0)? json.substring(1,json.length()-2):json;
TypeFactory typeFactory = mapper.getTypeFactory();
countryList = mapper.readValue(json, typeFactory.constructCollectionType(List.class, Country.class));
} catch (IOException e) {
e.printStackTrace();
}
return countryList;
}
但是这种方法不起作用。
我认为问题在于，由于所有对象都包含在数组中，因此仅凭TypeFactory中的List<Country>就无法实现这一点。有指针吗？
答案 0 :(得分：0)
由于@chrylis的建议，我能够使用TypeReference
private List<Country> jsonToCountryTypeRef(String json){
ObjectMapper mapper = new ObjectMapper();
TypeReference<List<Country>> typeRef
= new TypeReference<List<Country>>() {};
List<Country> o = null;
try {
o = mapper.readValue(json, typeRef);
} catch (IOException e) {
e.printStackTrace();
}
return o;
}