야후 환율 API 예제

1. API결과 json 객체로 변환 

StringBuilderresult =new StringBuilder();

try {

String krwStr = "USDKRW"; // default : USDKRW

if (type == 1) {

krwStr = "JPYKRW";

} else if (type == 2) {

krwStr = "EURKRW";

} else if (type == 3) {

krwStr = "CNYKRW";

}

String formatStr = "json"; // default : json

if (format == 1) {

formatStr = "xml";

}

                  

String urlStr = "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20yahoo.finance.xchange%20where%20pair%20in%20(%22" + krwStr + "%22)&format=" + formatStr + "&env=store://datatables.org/alltableswithkeys&callback=";

                  

URL url = new URL(urlStr);

                  

HttpURLConnection conn = (HttpURLConnection) url.openConnection();

                  

InputStream stream;

if (conn.getResponseCode() == 200) //success

stream = conn.getInputStream();

else

stream = conn.getErrorStream();

                  

BufferedReader reader = new BufferedReader(new InputStreamReader(stream));

String line;

while ((line = reader.readLine()) != null) {

result.append(line);

}

                  

JsonParser parser = new JsonParser();

JsonElement element = parser.parse(result.toString());

if (element.isJsonObject()) {

JsonObject obj = element.getAsJsonObject();

if (obj.get("error") == null) {

JsonObject translatedText = obj.get("query").

getAsJsonObject().

get("results").

getAsJsonObject().

get("rate").

getAsJsonObject();

return translatedText;

}

}

2. gson(json객체)를 map으로 변환

// 환율 정보 가져오기

FinanceXChangeUtil exchange = new FinanceXChangeUtil();

                  

// gson(jsonobject) to map

JsonObject nestedJSON = exchange.getFinanceXChangeValue(0, 0);

Gson gson = new Gson();

LinkedTreeMap result = gson.fromJson(nestedJSON , LinkedTreeMap.class);

                  

                  

// 환율 정보 담기

setAttribute("exchange_rate", result);

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