From 63dc267cc79e404b7ea1508509b8f95d4110d802 Mon Sep 17 00:00:00 2001
From: dp770 <dp770>
Date: Sun, 3 May 2020 20:10:10 +0100
Subject: [PATCH] Issue #561: [HitBTC] OrderBook is missing support of
 timestamp. Using built-in date time formatter with UTC timezone.

---
 .../hitbtc/dto/HitbtcWebSocketOrderBook.java  | 35 +++++++------------
 1 file changed, 13 insertions(+), 22 deletions(-)

diff --git a/xchange-stream-hitbtc/src/main/java/info/bitrich/xchangestream/hitbtc/dto/HitbtcWebSocketOrderBook.java b/xchange-stream-hitbtc/src/main/java/info/bitrich/xchangestream/hitbtc/dto/HitbtcWebSocketOrderBook.java
index 6abdec73c..42e07ddbd 100644
--- a/xchange-stream-hitbtc/src/main/java/info/bitrich/xchangestream/hitbtc/dto/HitbtcWebSocketOrderBook.java
+++ b/xchange-stream-hitbtc/src/main/java/info/bitrich/xchangestream/hitbtc/dto/HitbtcWebSocketOrderBook.java
@@ -3,10 +3,9 @@
 import static java.util.Collections.reverseOrder;
 
 import java.math.BigDecimal;
-import java.time.LocalDateTime;
-import java.time.ZoneOffset;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
-import java.time.format.DateTimeFormatterBuilder;
 import java.util.Date;
 import java.util.Map;
 import java.util.TreeMap;
@@ -15,44 +14,35 @@
 
 /** Created by Pavel Chertalev on 15.03.2018. */
 public class HitbtcWebSocketOrderBook {
-  // To parse dates in format of '2018-11-19T05:00:28.700Z'
-  private static DateTimeFormatter DATE_FORMAT =
-          new DateTimeFormatterBuilder().appendPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'").toFormatter();
+  private static DateTimeFormatter DATE_FORMAT = DateTimeFormatter.ISO_ZONED_DATE_TIME.withZone(ZoneId.of("UTC"));
   private Map<BigDecimal, HitbtcOrderLimit> asks;
   private Map<BigDecimal, HitbtcOrderLimit> bids;
   private long sequence = 0;
   private long timestamp = 0;
 
-  public HitbtcWebSocketOrderBook(HitbtcWebSocketOrderBookTransaction orderbookTransaction) {
-    createFromLevels(orderbookTransaction);
+  public HitbtcWebSocketOrderBook(HitbtcWebSocketOrderBookTransaction orderBookTransaction) {
+    createFromLevels(orderBookTransaction);
   }
 
-  private void createFromLevels(HitbtcWebSocketOrderBookTransaction orderbookTransaction) {
+  private void createFromLevels(HitbtcWebSocketOrderBookTransaction orderBookTransaction) {
     this.asks = new TreeMap<>(BigDecimal::compareTo);
     this.bids = new TreeMap<>(reverseOrder(BigDecimal::compareTo));
 
-    for (HitbtcOrderLimit orderBookItem : orderbookTransaction.getParams().getAsk()) {
+    for (HitbtcOrderLimit orderBookItem : orderBookTransaction.getParams().getAsk()) {
       if (orderBookItem.getSize().signum() != 0) {
         asks.put(orderBookItem.getPrice(), orderBookItem);
       }
     }
 
-    for (HitbtcOrderLimit orderBookItem : orderbookTransaction.getParams().getBid()) {
+    for (HitbtcOrderLimit orderBookItem : orderBookTransaction.getParams().getBid()) {
       if (orderBookItem.getSize().signum() != 0) {
         bids.put(orderBookItem.getPrice(), orderBookItem);
       }
     }
 
-    sequence = orderbookTransaction.getParams().getSequence();
-    timestamp = parseISOTimestampInUTC(orderbookTransaction.getParams().getTimestamp());
-  }
-
-  private long parseISOTimestampInUTC(String timestamp) {
-    if (timestamp != null) {
-        LocalDateTime time = LocalDateTime.parse(timestamp, DATE_FORMAT);
-        return time.toInstant(ZoneOffset.UTC).toEpochMilli();
-    }
-    return 0L;
+    sequence = orderBookTransaction.getParams().getSequence();
+    timestamp = ZonedDateTime.parse(orderBookTransaction.getParams().getTimestamp(), DATE_FORMAT)
+            .toInstant().toEpochMilli();
   }
 
   public HitbtcOrderBook toHitbtcOrderBook() {
@@ -69,7 +59,8 @@ public void updateOrderBook(HitbtcWebSocketOrderBookTransaction orderBookTransac
     updateOrderBookItems(orderBookTransaction.getParams().getAsk(), asks);
     updateOrderBookItems(orderBookTransaction.getParams().getBid(), bids);
     sequence = orderBookTransaction.getParams().getSequence();
-    timestamp = parseISOTimestampInUTC(orderBookTransaction.getParams().getTimestamp());
+    timestamp = ZonedDateTime.parse(orderBookTransaction.getParams().getTimestamp(), DATE_FORMAT)
+            .toInstant().toEpochMilli();
   }
 
   private void updateOrderBookItems(