Align java datetime types with the best practices and move away from local date time assumption to UTC

ozgliderpilot · ozgliderpilot · commit f98dd62e3b45 · 2026-04-16T17:27:32.000+10:00
diff --git a/memex/src/main/java/com/johnlpage/memex/VehicleInspection/controller/VehicleInspectionController.java b/memex/src/main/java/com/johnlpage/memex/VehicleInspection/controller/VehicleInspectionController.java
@@ -16,7 +16,9 @@
 import java.io.BufferedOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
-import java.util.Date;
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
 import java.util.Iterator;
 import java.util.List;
 import java.util.stream.Stream;
@@ -251,8 +253,9 @@ public ResponseEntity<StreamingResponseBody> streamJsonNative() {
 
     @GetMapping(value = "/inspections/asOf", produces = MediaType.APPLICATION_JSON_VALUE)
     public ResponseEntity<StreamingResponseBody> dataAtDate(
-            @RequestParam(name = "asOfDate") @DateTimeFormat(pattern = "yyyyMMddHHmmss") Date asOfDate,
+            @RequestParam(name = "asOfDate") @DateTimeFormat(pattern = "yyyyMMddHHmmss") LocalDateTime asOfDateParam,
             @RequestParam(name = "id") Long id) {
+        Instant asOfDate = asOfDateParam.atZone(ZoneOffset.UTC).toInstant();
         return ResponseEntity.ok()
                 .contentType(MediaType.APPLICATION_JSON)
                 .body(
diff --git a/memex/src/main/java/com/johnlpage/memex/VehicleInspection/model/VehicleInspection.java b/memex/src/main/java/com/johnlpage/memex/VehicleInspection/model/VehicleInspection.java
@@ -16,7 +16,7 @@
 import org.springframework.data.mongodb.core.mapping.Document;
 import org.springframework.data.mongodb.core.mapping.Field;
 
-import java.util.Date;
+import java.time.LocalDate;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -45,7 +45,7 @@ public class VehicleInspection {
     @Version
     Long lockVersion;
 
-    Date testdate;
+    LocalDate testdate;
     String testclass;
     String testtype;
     String testresult;
@@ -58,7 +58,7 @@ public class VehicleInspection {
 
     Long capacity;
 
-    Date firstusedate;
+    LocalDate firstusedate;
     /* Use this to flag from the JSON we want to remove the record */
     @Transient
     @DeleteFlag
diff --git a/memex/src/main/java/com/johnlpage/memex/VehicleInspection/service/VehicleInspectionHistoryService.java b/memex/src/main/java/com/johnlpage/memex/VehicleInspection/service/VehicleInspectionHistoryService.java
@@ -3,7 +3,7 @@
 import com.johnlpage.memex.VehicleInspection.model.VehicleInspection;
 import com.johnlpage.memex.VehicleInspection.repository.VehicleInspectionRepository;
 
-import java.util.Date;
+import java.time.Instant;
 import java.util.stream.Stream;
 
 import org.springframework.stereotype.Service;
@@ -19,7 +19,7 @@ public VehicleInspectionHistoryService(VehicleInspectionRepository repository) {
         this.repository = repository;
     }
 
-    public Stream<VehicleInspection> asOfDate(Long id, Date asOfDate) {
+    public Stream<VehicleInspection> asOfDate(Long id, Instant asOfDate) {
         return repository.GetRecordByIdAsOfDate(id, asOfDate, VehicleInspection.class);
     }
 }
diff --git a/memex/src/main/java/com/johnlpage/memex/generics/repository/MongoHistoryRepository.java b/memex/src/main/java/com/johnlpage/memex/generics/repository/MongoHistoryRepository.java
@@ -1,13 +1,13 @@
 package com.johnlpage.memex.generics.repository;
 
-import java.util.Date;
+import java.time.Instant;
 import java.util.stream.Stream;
 
 import org.springframework.data.mongodb.core.query.Criteria;
 
 public interface MongoHistoryRepository<T, I> {
 
-    Stream<T> GetRecordByIdAsOfDate(I recordId, Date asOf, Class<T> clazz);
+    Stream<T> GetRecordByIdAsOfDate(I recordId, Instant asOf, Class<T> clazz);
 
-    Stream<T> GetRecordsAsOfDate(Criteria criteria, Date asOf, Class<T> clazz);
+    Stream<T> GetRecordsAsOfDate(Criteria criteria, Instant asOf, Class<T> clazz);
 }
diff --git a/memex/src/main/java/com/johnlpage/memex/generics/repository/MongoHistoryRepositoryImpl.java b/memex/src/main/java/com/johnlpage/memex/generics/repository/MongoHistoryRepositoryImpl.java
@@ -13,6 +13,7 @@
 import org.springframework.data.mongodb.core.aggregation.*;
 import org.springframework.data.mongodb.core.query.Criteria;
 
+import java.time.Instant;
 import java.util.*;
 import java.util.stream.Stream;
 
@@ -29,12 +30,12 @@ public MongoHistoryRepositoryImpl(MongoTemplate mongoTemplate, MongoVersionBean
         this.mongoVersion = mongoVersion;
     }
 
-    public Stream<T> GetRecordByIdAsOfDate(I recordId, Date asOf, Class<T> clazz) {
+    public Stream<T> GetRecordByIdAsOfDate(I recordId, Instant asOf, Class<T> clazz) {
         Criteria criteria = Criteria.where("_id").is(recordId);
         return GetRecordsAsOfDate(criteria, asOf, clazz);
     }
 
-    public Stream<T> GetRecordsAsOfDate(Criteria criteria, Date asOf, Class<T> clazz) {
+    public Stream<T> GetRecordsAsOfDate(Criteria criteria, Instant asOf, Class<T> clazz) {
 
         List<AggregationOperation> stages = new ArrayList<>();
         String collectionName = AnnotationExtractor.getCollectionName(clazz);
diff --git a/memex/src/main/java/com/johnlpage/memex/generics/service/DocumentHistory.java b/memex/src/main/java/com/johnlpage/memex/generics/service/DocumentHistory.java
@@ -2,7 +2,7 @@
 
 import com.fasterxml.jackson.annotation.*;
 
-import java.util.Date;
+import java.time.Instant;
 import java.util.Map;
 
 import lombok.EqualsAndHashCode;
@@ -33,7 +33,7 @@ public class DocumentHistory {
     @EqualsAndHashCode.Include
     ObjectId historyId;
     Object recordId;
-    Date timestamp;
+    Instant timestamp;
     String type; // TOOO enum?
     Map<String, Object> changes;
 }
diff --git a/memex/src/main/java/com/johnlpage/memex/generics/service/HistoryTriggerService.java b/memex/src/main/java/com/johnlpage/memex/generics/service/HistoryTriggerService.java
@@ -11,6 +11,7 @@
 import com.mongodb.bulk.BulkWriteUpsert;
 import com.mongodb.client.ClientSession;
 
+import java.time.Instant;
 import java.util.*;
 
 import org.bson.Document;
@@ -60,7 +61,7 @@ public void postWriteTrigger(
                 DocumentHistory vih = new DocumentHistory();
                 vih.setRecordId(v.getId());
                 vih.setType("insert");
-                vih.setTimestamp(new Date());
+                vih.setTimestamp(Instant.now());
                 history.add(vih); // Add this history records to the history list
             }
         }
@@ -103,7 +104,7 @@ public void postWriteTrigger(
                 previousValues.remove(OptimizedMongoLoadRepositoryImpl.LAST_UPDATE_DATE);
 
                 vih.setChanges(previousValues);
-                vih.setTimestamp(new Date());
+                vih.setTimestamp(Instant.now());
                 history.add(vih); // Add this history records to the history list
             }
         }
@@ -123,7 +124,7 @@ public void postWriteTrigger(
                     });
                     vih.setChanges(finalState);
                     vih.setType("delete");
-                    vih.setTimestamp(new Date());
+                    vih.setTimestamp(Instant.now());
                     history.add(vih); // Add this history records to the history list
                 }
             }
diff --git a/memex/src/main/java/com/johnlpage/memex/util/MongoSchemaGenerator.java b/memex/src/main/java/com/johnlpage/memex/util/MongoSchemaGenerator.java
@@ -143,7 +143,13 @@ private static String mapJavaToBson(Class<?> type) {
         if (type == Boolean.class || type == boolean.class) return "bool";
         if (Date.class.isAssignableFrom(type)) return "date";
         if (type == java.time.Instant.class)
-            return "date"; // Works as logn as we have a typemapper
+            return "date"; // Works as long as we have a typemapper
+        if (type == java.time.LocalDate.class)
+            return "date"; // Stored as BSON Date via native java.time codecs
+        if (type == java.time.LocalTime.class)
+            return "date"; // Stored as BSON Date via native java.time codecs
+        if (type == java.time.LocalDateTime.class)
+            return "date"; // Stored as BSON Date via native java.time codecs
         if (UUID.class.isAssignableFrom(type)) return "string";
 
         // Native BSON types (preferred for performance)
@@ -208,7 +214,8 @@ private static String createErrorMessage(Class<?> type) {
         if (pkg.startsWith("java.time")) {
             return "Unsupported type: "
                     + type.getName()
-                    + ". Convert to java.util.Date or store as ISO-8601 String or epoch Long.";
+                    + ". Use Instant for timestamps, LocalDate for date-only values, LocalTime for time-only values,"
+                    + " LocalDateTime for combined date/time, or store as ISO-8601 String or epoch Long.";
         }
 
         if (pkg.startsWith("java.sql")) {
diff --git a/memex/src/main/java/com/johnlpage/memex/util/ObjectConverter.java b/memex/src/main/java/com/johnlpage/memex/util/ObjectConverter.java
@@ -2,10 +2,14 @@
 
 import java.time.LocalDate;
 import java.time.LocalDateTime;
+import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
 import java.time.format.DateTimeParseException;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 
 public class ObjectConverter {
 
@@ -32,18 +36,13 @@ public static Object convertObject(Object input) {
             // Try parsing as different date/time types
             if (str.contains("T")) {
               if (str.contains("Z") || str.contains("+") || str.contains("-")) {
-                return Date.from(ZonedDateTime.parse(str, formatter).toInstant());
+                return ZonedDateTime.parse(str, formatter).toInstant();
               } else {
-                return Date.from(
-                    LocalDateTime.parse(str, formatter)
-                        .atZone(java.time.ZoneOffset.UTC)
-                        .toInstant());
+                return LocalDateTime.parse(str, formatter)
+                    .toInstant(ZoneOffset.UTC);
               }
             } else {
-              return Date.from(
-                  LocalDate.parse(str, formatter)
-                      .atStartOfDay(java.time.ZoneOffset.UTC)
-                      .toInstant());
+              return LocalDate.parse(str, formatter);
             }
           } catch (DateTimeParseException e) {
             // Continue to next formatter
diff --git a/memex/src/test/java/com/johnlpage/memex/cucumber/steps/TimeManagementSteps.java b/memex/src/test/java/com/johnlpage/memex/cucumber/steps/TimeManagementSteps.java
@@ -4,6 +4,7 @@
 import io.cucumber.java.en.Given;
 import org.springframework.beans.factory.annotation.Autowired;
 
+import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.concurrent.TimeUnit;
@@ -15,7 +16,7 @@ public class TimeManagementSteps {
 
     @Given("I capture the current timestamp to {string} with {string} pattern")
     public void iCaptureTheCurrentTimestamp(String macroName, String datePattern) {
-        ZonedDateTime capturedTimestamp = ZonedDateTime.now();
+        ZonedDateTime capturedTimestamp = ZonedDateTime.now(ZoneOffset.UTC);
         macroRegister.registerMacro(macroName, capturedTimestamp.format(DateTimeFormatter.ofPattern(datePattern)));
     }
 
diff --git a/memex/src/test/resources/features/inspections.rest.asof.feature b/memex/src/test/resources/features/inspections.rest.asof.feature
@@ -16,15 +16,15 @@ Feature: Vehicle Inspection REST API - Point-in-Time History (As Of)
       [
         {
           "testid": 10001,
-          "testdate": "2025-10-27T11:00:00Z",
+          "testdate": "2025-10-27",
           "testclass": "Class 2",
           "testtype": "Interim",
           "testresult": "PASS",
           "testmileage": 60000,
           "postcode": "SW1A 0AB",
           "fuel": "Diesel",
           "capacity": 90,
-          "firstusedate": "2019-03-20T00:00:00Z",
+          "firstusedate": "2019-03-20",
           "faileditems": ["Brakes", "Lights"],
           "vehicle": {
             "make": "Ford",
diff --git a/memex/src/test/resources/features/inspections.rest.streams.feature b/memex/src/test/resources/features/inspections.rest.streams.feature
@@ -11,15 +11,15 @@ Feature: Vehicle Inspection REST API - Data Streaming Capabilities
       [
         {
           "testid": <id1>,
-          "testdate": "2023-10-26T10:00:00Z",
+          "testdate": "2023-10-26",
           "testclass": "Class 1",
           "testtype": "Annual",
           "testresult": "PASS",
           "testmileage": 50000,
           "postcode": "SW1A 0AA",
           "fuel": "Petrol",
           "capacity": 56,
-          "firstusedate": "2018-01-15T00:00:00Z",
+          "firstusedate": "2018-01-15",
           "faileditems": [],
           "vehicle": {
             "make": "Toyota",
@@ -30,15 +30,15 @@ Feature: Vehicle Inspection REST API - Data Streaming Capabilities
         },
         {
           "testid": <id2>,
-          "testdate": "2023-10-27T11:00:00Z",
+          "testdate": "2023-10-27",
           "testclass": "Class 2",
           "testtype": "Interim",
           "testresult": "FAIL",
           "testmileage": 60000,
           "postcode": "SW1A 0AB",
           "fuel": "Diesel",
           "capacity": 76,
-          "firstusedate": "2019-03-20T00:00:00Z",
+          "firstusedate": "2019-03-20",
           "faileditems": ["Brakes", "Lights"],
           "vehicle": {
             "make": "Ford",
@@ -88,11 +88,11 @@ Feature: Vehicle Inspection REST API - Data Streaming Capabilities
       [
         {
           "testid": 10001,
-          "testdate": "2023-10-26T10:00:00Z"
+          "testdate": "2023-10-26"
         },
         { // Malformed object, missing closing brace
           "testid": 10002,
-          "testdate": "2023-10-27T11:00:00Z"
+          "testdate": "2023-10-27"
       ]
       """
     Then the response status code should be 207
diff --git a/memex/templates/controller/Controller.java.template b/memex/templates/controller/Controller.java.template
@@ -13,7 +13,9 @@ import jakarta.servlet.http.HttpServletRequest;
 import java.io.BufferedOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
-import java.util.Date;
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
 import java.util.Iterator;
 import java.util.List;
 import java.util.stream.Stream;
@@ -209,8 +211,9 @@ public class __className__Controller {
      */
     @GetMapping(value = "/__apiPath__/asOf", produces = MediaType.APPLICATION_JSON_VALUE)
     public ResponseEntity<StreamingResponseBody> dataAtDate(
-            @RequestParam(name = "asOfDate") @DateTimeFormat(pattern = "yyyyMMddHHmmss") Date asOfDate,
+            @RequestParam(name = "asOfDate") @DateTimeFormat(pattern = "yyyyMMddHHmmss") LocalDateTime asOfDateParam,
             @RequestParam(name = "id") __idType__ id) {
+        Instant asOfDate = asOfDateParam.atZone(ZoneOffset.UTC).toInstant();
         return ResponseEntity.ok()
             .contentType(MediaType.APPLICATION_JSON)
             .body(
diff --git a/memex/templates/scripts/generate-models-from-json.groovy b/memex/templates/scripts/generate-models-from-json.groovy
@@ -384,8 +384,11 @@ determineType = { String fieldName, Object value, String parentClassName ->
     if (value instanceof String) {
         String strVal = (String) value
 
-        if (strVal ==~ /^\d{4}-\d{2}-\d{2}.*/ || strVal ==~ /.*T\d{2}:\d{2}:\d{2}.*/) {
-            return [type: 'Date', isComplex: false, imports: ['java.util.Date']]
+        if (strVal ==~ /.*T\d{2}:\d{2}:\d{2}.*/) {
+            return [type: 'Instant', isComplex: false, imports: ['java.time.Instant']]
+        }
+        if (strVal ==~ /^\d{4}-\d{2}-\d{2}$/) {
+            return [type: 'LocalDate', isComplex: false, imports: ['java.time.LocalDate']]
         }
         return [type: 'String', isComplex: false]
     }
diff --git a/memex/templates/service/HistoryService.java.template b/memex/templates/service/HistoryService.java.template
@@ -2,7 +2,7 @@ package __package__.__className__.service;
 
 import __package__.__className__.model.__className__;
 import __package__.__className__.repository.__className__Repository;
-import java.util.Date;
+import java.time.Instant;
 import java.util.stream.Stream;
 import org.springframework.stereotype.Service;
 __idImport__
@@ -18,7 +18,7 @@ public class __className__HistoryService {
         this.repository = repository;
     }
 
-    public Stream<__className__> asOfDate(__idType__ id, Date asOfDate) {
+    public Stream<__className__> asOfDate(__idType__ id, Instant asOfDate) {
         return repository.GetRecordByIdAsOfDate(id, asOfDate, __className__.class);
     }
 }

Original file line number	Diff line number	Diff line change
`@@ -3,7 +3,7 @@`
`3`	`3`	`import com.johnlpage.memex.VehicleInspection.model.VehicleInspection;`
`4`	`4`	`import com.johnlpage.memex.VehicleInspection.repository.VehicleInspectionRepository;`
`5`	`5`
`6`		`-import java.util.Date;`
	`6`	`+import java.time.Instant;`
`7`	`7`	`import java.util.stream.Stream;`
`8`	`8`
`9`	`9`	`import org.springframework.stereotype.Service;`
`@@ -19,7 +19,7 @@ public VehicleInspectionHistoryService(VehicleInspectionRepository repository) {`
`19`	`19`	`this.repository = repository;`
`20`	`20`	`}`
`21`	`21`
`22`		`- public Stream<VehicleInspection> asOfDate(Long id, Date asOfDate) {`
	`22`	`+ public Stream<VehicleInspection> asOfDate(Long id, Instant asOfDate) {`
`23`	`23`	`return repository.GetRecordByIdAsOfDate(id, asOfDate, VehicleInspection.class);`
`24`	`24`	`}`
`25`	`25`	`}`
Original file line number	Diff line number	Diff line change
`@@ -11,6 +11,7 @@`
`11`	`11`	`import com.mongodb.bulk.BulkWriteUpsert;`
`12`	`12`	`import com.mongodb.client.ClientSession;`
`13`	`13`
	`14`	`+import java.time.Instant;`
`14`	`15`	`import java.util.*;`
`15`	`16`
`16`	`17`	`import org.bson.Document;`
`@@ -60,7 +61,7 @@ public void postWriteTrigger(`
`60`	`61`	`DocumentHistory vih = new DocumentHistory();`
`61`	`62`	`vih.setRecordId(v.getId());`
`62`	`63`	`vih.setType("insert");`
`63`		`- vih.setTimestamp(new Date());`
	`64`	`+ vih.setTimestamp(Instant.now());`
`64`	`65`	`history.add(vih); // Add this history records to the history list`
`65`	`66`	`}`
`66`	`67`	`}`
`@@ -103,7 +104,7 @@ public void postWriteTrigger(`
`103`	`104`	`previousValues.remove(OptimizedMongoLoadRepositoryImpl.LAST_UPDATE_DATE);`
`104`	`105`
`105`	`106`	`vih.setChanges(previousValues);`
`106`		`- vih.setTimestamp(new Date());`
	`107`	`+ vih.setTimestamp(Instant.now());`
`107`	`108`	`history.add(vih); // Add this history records to the history list`
`108`	`109`	`}`
`109`	`110`	`}`
`@@ -123,7 +124,7 @@ public void postWriteTrigger(`
`123`	`124`	`});`
`124`	`125`	`vih.setChanges(finalState);`
`125`	`126`	`vih.setType("delete");`
`126`		`- vih.setTimestamp(new Date());`
	`127`	`+ vih.setTimestamp(Instant.now());`
`127`	`128`	`history.add(vih); // Add this history records to the history list`
`128`	`129`	`}`
`129`	`130`	`}`