Replace deprecated JsonParser constructor and parse method

with the static JsonParser#parseString method.

Change-Id: Ic75c86c6b6d102f1a78bf7d9b594a03089174887

src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java

diff --git a/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java b/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
index c022978..951c2d9 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
@@ -289,7 +289,7 @@
           contentType.toString().equalsIgnoreCase(ContentType.APPLICATION_JSON.toString()),
           String.format("Expected %s, but was: %s", ContentType.APPLICATION_JSON, contentType));
       String responseStr = EntityUtils.toString(response.getEntity());
-      JsonObject responseJson = (JsonObject) new JsonParser().parse(responseStr);
+      JsonObject responseJson = JsonParser.parseString(responseStr).getAsJsonObject();
       boolean hasErrors = responseJson.get("errors").getAsBoolean();
       if (hasErrors) {
         logger.atSevere().log("Response with errors: %s", responseJson);
@@ -318,7 +318,7 @@
   }
 
   protected String getSearch(SearchSourceBuilder searchSource, JsonArray sortArray) {
-    JsonObject search = new JsonParser().parse(searchSource.toString()).getAsJsonObject();
+    JsonObject search = JsonParser.parseString(searchSource.toString()).getAsJsonObject();
     search.add("sort", sortArray);
     return gson.toJson(search);
   }
@@ -432,7 +432,7 @@
         if (statusLine.getStatusCode() == HttpStatus.SC_OK) {
           String content = getContent(response);
           JsonObject obj =
-              new JsonParser().parse(content).getAsJsonObject().getAsJsonObject("hits");
+              JsonParser.parseString(content).getAsJsonObject().getAsJsonObject("hits");
           if (obj.get("hits") != null) {
             JsonArray json = obj.getAsJsonArray("hits");
             ImmutableList.Builder<T> results = ImmutableList.builderWithExpectedSize(json.size());

src/main/java/com/google/gerrit/elasticsearch/ElasticIndexVersionDiscovery.java

diff --git a/src/main/java/com/google/gerrit/elasticsearch/ElasticIndexVersionDiscovery.java b/src/main/java/com/google/gerrit/elasticsearch/ElasticIndexVersionDiscovery.java
index 4217f45..9e670ee 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ElasticIndexVersionDiscovery.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ElasticIndexVersionDiscovery.java
@@ -53,9 +53,9 @@
       throw new IOException(message);
     }
 
-    return new JsonParser()
-        .parse(AbstractElasticIndex.getContent(response)).getAsJsonObject().entrySet().stream()
-            .map(e -> e.getKey().replace(name, ""))
-            .collect(toList());
+    return JsonParser.parseString(AbstractElasticIndex.getContent(response)).getAsJsonObject()
+        .entrySet().stream()
+        .map(e -> e.getKey().replace(name, ""))
+        .collect(toList());
   }
 }

src/main/java/com/google/gerrit/elasticsearch/ElasticRestClientProvider.java

diff --git a/src/main/java/com/google/gerrit/elasticsearch/ElasticRestClientProvider.java b/src/main/java/com/google/gerrit/elasticsearch/ElasticRestClientProvider.java
index 9caa14d..ebf1eec 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ElasticRestClientProvider.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ElasticRestClientProvider.java
@@ -116,8 +116,7 @@
         throw new FailedToGetVersion(statusLine);
       }
       String version =
-          new JsonParser()
-              .parse(AbstractElasticIndex.getContent(response))
+          JsonParser.parseString(AbstractElasticIndex.getContent(response))
               .getAsJsonObject()
               .get("version")
               .getAsJsonObject()