本文整理了Java中com.google.cloud.datastore.Datastore.update()方法的一些代码示例，展示了Datastore.update()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Datastore.update()方法的具体详情如下：
包路径：com.google.cloud.datastore.Datastore
类名称：Datastore
方法名：update

Datastore.update介绍

[英]Example of updating multiple entities.

String keyName1 = "my_key_name_1";

[中]更新多个实体的示例。

String keyName1 = "my_key_name_1";

代码示例

代码示例来源：origin: googleapis/google-cloud-java

public static void main(String... args) {
  Datastore datastore = DatastoreOptions.getDefaultInstance().getService();
  KeyFactory keyFactory = datastore.newKeyFactory().setKind("keyKind");
  Key key = keyFactory.newKey("keyName");
  Entity entity = datastore.get(key);
  if (entity != null) {
   System.out.println("Updating access_time for " + entity.getString("name"));
   entity = Entity.newBuilder(entity).set("access_time", Timestamp.now()).build();
   datastore.update(entity);
  }
 }
}

代码示例来源：origin: googleapis/google-cloud-java

/** Example of updating multiple entities. */
// [TARGET update(Entity...)]
// [VARIABLE "my_key_name_1"]
// [VARIABLE "my_key_name_2"]
public void batchUpdateEntities(String keyName1, String keyName2) {
 // [START batchUpdateEntities]
 Key key1 = datastore.newKeyFactory().setKind("MyKind").newKey(keyName1);
 Entity.Builder entityBuilder1 = Entity.newBuilder(key1);
 entityBuilder1.set("propertyName", "updatedValue1");
 Entity entity1 = entityBuilder1.build();
 Key key2 = datastore.newKeyFactory().setKind("MyKind").newKey(keyName2);
 Entity.Builder entityBuilder2 = Entity.newBuilder(key2);
 entityBuilder2.set("propertyName", "updatedValue2");
 Entity entity2 = entityBuilder2.build();
 datastore.update(entity1, entity2);
 // [END batchUpdateEntities]
}

代码示例来源：origin: googleapis/google-cloud-java

@Test
public void testUpdate() {
 List<Entity> keys = DATASTORE.fetch(ENTITY1.getKey(), ENTITY3.getKey());
 assertEquals(ENTITY1, keys.get(0));
 assertNull(keys.get(1));
 assertEquals(2, keys.size());
 try {
  DATASTORE.update(ENTITY3);
  fail("Expecting a failure");
 } catch (DatastoreException expected) {
  // expected;
 }
 DATASTORE.add(ENTITY3);
 assertEquals(ENTITY3, DATASTORE.get(ENTITY3.getKey()));
 Entity entity3 = Entity.newBuilder(ENTITY3).clear().set("bla", new NullValue()).build();
 assertNotEquals(ENTITY3, entity3);
 DATASTORE.update(entity3);
 assertEquals(entity3, DATASTORE.get(ENTITY3.getKey()));
}

代码示例来源：origin: googleapis/google-cloud-java

@Test
public void testUpdate() {
 List<Entity> keys = datastore.fetch(ENTITY1.getKey(), ENTITY3.getKey());
 assertEquals(ENTITY1, keys.get(0));
 assertNull(keys.get(1));
 assertEquals(2, keys.size());
 try {
  datastore.update(ENTITY3);
  fail("Expecting a failure");
 } catch (DatastoreException expected) {
  // expected;
 }
 datastore.add(ENTITY3);
 assertEquals(ENTITY3, datastore.get(ENTITY3.getKey()));
 Entity entity3 = Entity.newBuilder(ENTITY3).clear().set("bla", new NullValue()).build();
 assertNotEquals(ENTITY3, entity3);
 datastore.update(entity3);
 assertEquals(entity3, datastore.get(ENTITY3.getKey()));
}

代码示例来源：origin: GoogleCloudPlatform/java-docs-samples

/**
 * Updates a user in Cloud Datastore.
 */
public User updateUser(String id, String name, String email) {
 failIfInvalid(name, email);
 Key key = keyFactory.newKey(id);
 Entity entity = datastore.get(key);
 if (entity == null) {
  throw new IllegalArgumentException("No user with id '" + id + "' found");
 } else {
  entity = Entity.newBuilder(entity)
    .set("id", id)
    .set("name", name)
    .set("email", email)
    .build();
  datastore.update(entity);
 }
 return new User(id, name, email);
}

代码示例来源：origin: stackoverflow.com

Datastore ds = TransactionItem.ds();
UpdateOperations<TransactionItem> op = ds.createUpdateOperations(TransactionItem.class).set("paidInvoiceDocNum", String.valueOf(docNumber));
Query<TransactionItem> q = (Query<TransactionItem>)TransactionItem.q().filter("id in", itemsIds).getMorphiaQuery();
ds.update(q, op);