feat: add optimistic locking to Firestore sample app

Author: mehdi0933

spring-cloud-gcp-data-datastore/src/main/java/com/google/cloud/spring/data/datastore/core/mapping/DatastorePersistentProperty.java

@@ -1,11 +1,11 @@
 /*
- * Copyright 2017-2019 the original author or authors.
+ * Copyright 2017-2026 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
- *      https://www.apache.org/licenses/LICENSE-2.0
+ * https://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
@@ -70,12 +70,12 @@ public interface DatastorePersistentProperty
    */
   boolean isLazyLoaded();
 
+  boolean isSkipNullValue();
+
   /**
    * Return whether to skip null value, i.e., skip insertion if value is null.
    *
    * @return {@code true} if the null value is skipped. {@code false} otherwise.
    */
-  default boolean isSkipNullValue() {
-    return false;
-  }
-}
+  boolean shouldSkipNullValue();
+}

spring-cloud-gcp-data-datastore/src/main/java/com/google/cloud/spring/data/datastore/core/mapping/DatastorePersistentPropertyImpl.java

@@ -1,11 +1,11 @@
 /*
- * Copyright 2017-2019 the original author or authors.
+ * Copyright 2017-2026 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
- *      https://www.apache.org/licenses/LICENSE-2.0
+ * https://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
@@ -38,7 +38,7 @@ public class DatastorePersistentPropertyImpl
 
   private final FieldNamingStrategy fieldNamingStrategy;
 
-  private final boolean isSkipNullValue;
+  private final boolean skipNullValue;
 
   /**
    * Constructor.
@@ -47,19 +47,20 @@ public class DatastorePersistentPropertyImpl
    * @param owner the entity to which this property belongs
    * @param simpleTypeHolder the type holder
    * @param fieldNamingStrategy the naming strategy used to get the column name of this property
+   * @param skipNullValue whether to skip null values during saving
    */
   DatastorePersistentPropertyImpl(
       Property property,
       PersistentEntity<?, DatastorePersistentProperty> owner,
       SimpleTypeHolder simpleTypeHolder,
       FieldNamingStrategy fieldNamingStrategy,
-      boolean isSkipNullValue) {
+      boolean skipNullValue) {
     super(property, owner, simpleTypeHolder);
     this.fieldNamingStrategy =
         (fieldNamingStrategy != null)
             ? fieldNamingStrategy
             : PropertyNameFieldNamingStrategy.INSTANCE;
-    this.isSkipNullValue = isSkipNullValue;
+    this.skipNullValue = skipNullValue;
     verify();
   }
 
@@ -137,7 +138,7 @@ public boolean isLazyLoaded() {
   }
 
   @Override
-  public boolean isSkipNullValue() {
-    return isSkipNullValue;
+  public boolean shouldSkipNullValue() {
+    return this.skipNullValue;
   }
-}
+}

spring-cloud-gcp-samples/spring-cloud-gcp-data-firestore-sample/src/main/java/com/example/User.java

@@ -5,7 +5,7 @@
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
- *      https://www.apache.org/licenses/LICENSE-2.0
+ * https://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
@@ -21,6 +21,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
+import org.springframework.data.annotation.Version;
 
 /** Example POJO to demonstrate Spring Cloud GCP Spring Data Firestore operations. */
 @Document(collectionName = "users")
@@ -32,6 +33,13 @@ public class User {
 
   List<Pet> pets;
 
+  /**
+   * The version field enables optimistic locking.
+   * Spring Data increments this value automatically on every update.
+   */
+  @Version
+  Long version;
+
   User() {
     pets = new ArrayList<>();
   }
@@ -66,6 +74,14 @@ public void setPets(List<Pet> pets) {
     this.pets = pets;
   }
 
+  public Long getVersion() {
+    return version;
+  }
+
+  public void setVersion(Long version) {
+    this.version = version;
+  }
+
   @Override
   public boolean equals(Object o) {
     if (this == o) {
@@ -75,16 +91,24 @@ public boolean equals(Object o) {
       return false;
     }
     User user = (User) o;
-    return age == user.age && Objects.equals(name, user.name) && Objects.equals(pets, user.pets);
+    return age == user.age
+        && Objects.equals(name, user.name)
+        && Objects.equals(pets, user.pets)
+        && Objects.equals(version, user.version);
   }
 
   @Override
   public int hashCode() {
-    return Objects.hash(name, age, pets);
+    return Objects.hash(name, age, pets, version);
   }
 
   @Override
   public String toString() {
-    return "User{" + "name='" + name + '\'' + ", age=" + age + ", pets=" + pets + '}';
+    return "User{"
+        + "name='" + name + '\''
+        + ", age=" + age
+        + ", pets=" + pets
+        + ", version=" + version
+        + '}';
   }
-}
+}