import java.io.BufferedReader;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.lang.reflect.Type;

import java.net.HttpURLConnection;

import java.net.ProtocolException;

import java.net.URL;

import java.security.SignatureException;

import java.text.SimpleDateFormat;

import java.util.ArrayList;

import java.util.Calendar;

import java.util.List;

import java.util.Locale;

import java.util.TimeZone;

import java.util.zip.GZIPInputStream;

import com.google.gson.Gson;

import com.google.gson.reflect.TypeToken;

public class SignatureTest {

public static void main(String[] args) {

HttpURLConnection connection=null;

String APIUrl = "https://ptx.transportdata.tw/MOTC/v2/Bus/RealTimeByFrequency/City/Chiayi?$top=1&$format=JSON";

//申請的APPID

//（FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF 為 Guest 帳號，以IP作為API呼叫限制，請替換為註冊的APPID & APPKey）

String APPID = "FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF";

//申請的APPKey

String APPKey = "FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF";

//取得當下的UTC時間，Java8有提供時間格式DateTimeFormatter.RFC_1123_DATE_TIME

//但是格式與C#有一點不同，所以只能自行定義

String xdate = getServerTime();

String SignDate = "x-date: " + xdate;

String Signature="";

try {

//取得加密簽章

Signature = HMAC_SHA1.Signature(SignDate, APPKey);

} catch (SignatureException e1) {

// TODO Auto-generated catch block

e1.printStackTrace();

}

System.out.println("Signature :" + Signature);

String sAuth = "hmac username=\"" + APPID + "\", algorithm=\"hmac-sha1\", headers=\"x-date\", signature=\"" + Signature + "\"";

System.out.println(sAuth);

try{

URL url=new URL(APIUrl);

if("https".equalsIgnoreCase(url.getProtocol())){

SslUtils.ignoreSsl();

}

connection=(HttpURLConnection)url.openConnection();

connection.setRequestMethod("GET");

connection.setRequestProperty("Authorization", sAuth);

connection.setRequestProperty("x-date", xdate);

connection.setRequestProperty("Accept-Encoding", "gzip");

connection.setDoInput(true);

connection.setDoOutput(true);

//返回的數據已經過解壓

InputStream inputStream = connection.getInputStream();

InputStreamReader reader = new InputStreamReader(inputStream,"UTF-8");

BufferedReader in = new BufferedReader(reader);

//讀取回傳資料

String line, response="";

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

response+=(line+"\n");

}

Type RailStationListType = new TypeToken<ArrayList<RailStation>>(){}.getType();

Gson gsonReceiver = new Gson();

List<RailStation> obj = gsonReceiver.fromJson(response, RailStationListType);

System.out.println(response);

}catch(ProtocolException e){

e.printStackTrace();

}

catch(Exception e){

e.printStackTrace();

}

}

//取得當下UTC時間

public static String getServerTime() {

Calendar calendar = Calendar.getInstance();

SimpleDateFormat dateFormat = new SimpleDateFormat(

"EEE, dd MMM yyyy HH:mm:ss z", Locale.US);

dateFormat.setTimeZone(TimeZone.getTimeZone("GMT"));

return dateFormat.format(calendar.getTime());

}

}