Handle Request batchId

src/main/java/org/opentripplanner/middleware/controllers/api/OtpRequestProcessor.java

@@ -190,12 +190,8 @@ private String proxyPost(Request request, Response response) {
                 *
                 * Other requests will still be proxied, just not stored.
                 */
-                QueryVariables queryVariables = getPOJOFromJSON(requestBody, Query.class).variables;
-
-                // Follows the method used in otp-ui core-utils storage.js
-                String randomBatchId = Integer.toString((int) (Math.random() * 1_000_000_000), 36);
-
-                if (!handlePlanTripResponse(randomBatchId, queryVariables, otpDispatcherResponse, otpUser)) {
+                Query query = getPOJOFromJSON(requestBody, Query.class);
+                if (!handlePlanTripResponse(query.batchId, query.variables, otpDispatcherResponse, otpUser)) {
                     logMessageAndHalt(
                             request,
                             HttpStatus.INTERNAL_SERVER_ERROR_500,

src/main/java/org/opentripplanner/middleware/otp/graphql/Query.java

@@ -1,7 +1,17 @@
 package org.opentripplanner.middleware.otp.graphql;
 
-/** Wraps an OTP GraphQL query data. Field names below are defined by OTP. */
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonInclude;
+
+/**
+ * Wraps an OTP GraphQL query data.
+ * Field names below are defined by OTP, except for batchId which helps group OTP plan requests for a particular search.
+ */
+@JsonInclude(JsonInclude.Include.NON_NULL)
+@JsonIgnoreProperties(ignoreUnknown = true)
 public class Query {
+    public String batchId;
+
     public String query;
 
     public QueryVariables variables;