### Start Server and Client Applications

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-pubsub-bus-config-sample/README.adoc

Commands to start the Spring Cloud GCP Pub/Sub Bus Config Server and Client applications using Maven.

```bash
cd spring-cloud-gcp-samples/spring-cloud-gcp-pubsub-bus-config-sample
mvn spring-boot:run -f spring-cloud-gcp-pubsub-bus-config-sample-server-github
```

```bash
cd spring-cloud-gcp-samples/spring-cloud-gcp-pubsub-bus-config-sample
mvn spring-boot:run -f spring-cloud-gcp-pubsub-bus-config-sample-client
```

--------------------------------

### OCR Dependencies Setup

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/vision.adoc

If applying OCR on documents, include both vision and storage starters.

```APIDOC
==== Cloud Vision OCR Dependencies

If you are interested in applying optical character recognition (OCR) on documents for your project, you'll need to add both `spring-cloud-gcp-starter-vision` and `spring-cloud-gcp-starter-storage` to your dependencies.
The storage starter is necessary because the Cloud Vision API will process your documents and write OCR output files all within your Google Cloud Storage buckets.

Maven coordinates using <<getting-started.adoc#bill-of-materials, Spring Framework on Google Cloud BOM>>:

[source,xml]
----
<dependency>
  <groupId>com.google.cloud</groupId>
  <artifactId>spring-cloud-gcp-starter-vision</artifactId>
</dependency>
<dependency>
  <groupId>com.google.cloud</groupId>
  <artifactId>spring-cloud-gcp-starter-storage</artifactId>
</dependency>
----

Gradle coordinates:

[source]
----
dependencies {
  implementation("com.google.cloud:spring-cloud-gcp-starter-vision")
  implementation("com.google.cloud:spring-cloud-gcp-starter-storage")
}
----
```

--------------------------------

### Query by Example with Fluent Query Chaining

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

Chain query specifications using a fluent API after defining an example. This allows for complex queries with sorting and limiting results.

```java
userRepository.findBy(
    Example.of(new User(null, null, "Smith")), q -> q.sortBy(Sort.by("firstName")).firstValue());

userRepository.findBy(
    Example.of(new User(null, null, "Smith")), FetchableFluentQuery::stream);

```

--------------------------------

### Start Client Application

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-pubsub-bus-config-sample/README.adoc

Run the Spring Cloud client application using Maven. This client will subscribe to configuration changes.

```bash
cd spring-cloud-gcp-samples/spring-cloud-gcp-pubsub-bus-config-sample
mvn spring-boot:run -pl spring-cloud-gcp-pubsub-bus-config-sample-client
```

--------------------------------

### Maven Dependency Setup

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/vision.adoc

Add the spring-cloud-gcp-starter-vision artifact to your project using Maven.

```APIDOC
## Maven Dependency Setup

Maven coordinates, using <<getting-started.adoc#bill-of-materials, Spring Framework on Google Cloud BOM>>:

[source,xml]
----
<dependency>
  <groupId>com.google.cloud</groupId>
  <artifactId>spring-cloud-gcp-starter-vision</artifactId>
</dependency>
----
```

--------------------------------

### DatastoreOperations Transaction Example

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

Provides an example of performing a transaction using DatastoreOperations.performTransaction, which accepts a function to execute within the transaction context.

```java
@Autowired
DatastoreOperations myDatastoreOperations;

public String doWorkInsideTransaction() {
  return myDatastoreOperations.performTransaction(
    transactionDatastoreOperations -> {
      // Work with transactionDatastoreOperations here.
      // It is also a DatastoreOperations object.

      return "transaction completed";
    }
  );
}
```

--------------------------------

### Gradle Dependency Setup

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/vision.adoc

Add the spring-cloud-gcp-starter-vision artifact to your project using Gradle.

```APIDOC
## Gradle Dependency Setup

Gradle coordinates:

[source]
----
dependencies {
  implementation("com.google.cloud:spring-cloud-gcp-starter-vision")
}
----
```

--------------------------------

### Reactive Stream Subscriber Setup (Java)

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/pubsub.adoc

Acquire a reactive stream backed by a Pub/Sub subscription using PubSubReactiveFactory. Requires Project Reactor dependency.

```java
@Autowired
PubSubReactiveFactory reactiveFactory;

// ...

Flux<AcknowledgeablePubsubMessage>
				= reactiveFactory.poll("exampleSubscription", 1000);
```

--------------------------------

### DatastoreTemplate Usage Example

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

Demonstrates basic usage of DatastoreTemplate for deleting all entities, saving a new entity, and retrieving all entities of a specific type.

```java
@SpringBootApplication
public class DatastoreTemplateExample {

	@Autowired
	DatastoreTemplate datastoreTemplate;

	public void doSomething() {
		this.datastoreTemplate.deleteAll(Trader.class);
		//...
		Trader t = new Trader();
		//...
		this.datastoreTemplate.save(t);
		//...
		List<Trader> traders = datastoreTemplate.findAll(Trader.class);
		//...
	}
}
```

--------------------------------

### Start Configuration Server (Local)

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-pubsub-bus-config-sample/README.adoc

Run the Spring Cloud Config server locally using Maven. This server will read configurations from the local filesystem.

```bash
cd spring-cloud-gcp-samples/spring-cloud-gcp-pubsub-bus-config-sample
mvn spring-boot:run -pl spring-cloud-gcp-pubsub-bus-config-sample-server-local
```

--------------------------------

### Example JSON Data for Upload

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-bigquery-sample/src/main/resources/templates/upload-json.html

This is an example of newline-delimited JSON rows that can be uploaded directly.

```json
{"CompanyName":"TALES","Description":"mark","SerialNumber":97,"Leave":0,"EmpName":"Mark"} {"CompanyName":"1Q84","Description":"ark","SerialNumber":978,"Leave":0,"EmpName":"HARUKI"} {"CompanyName":"MY","Description":"M","SerialNumber":9780,"Leave":0,"EmpName":"Mark"}
```

--------------------------------

### Curl Command Example

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-security-firebase-sample/src/main/resources/static/index.html

Example curl command to test the /answer endpoint with an Authorization header. This demonstrates how to make authenticated requests from the command line.

```bash
curl -H "Authorization: Bearer <your-access-token>" http://localhost:8080/answer
```

--------------------------------

### Run All Project Tests

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/CONTRIBUTING.md

Execute all tests for the project using the Maven wrapper. Ensure Java 17 or later is installed.

```bash
./mvnw clean test
```

--------------------------------

### DatastoreTemplate Find by ID Examples

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

Shows how to find single or multiple entities by their IDs, and how to retrieve all entities of a given Kind using DatastoreTemplate.

```java
Trader trader = this.datastoreTemplate.findById("trader1", Trader.class);
```

```java
List<Trader> traders = this.datastoreTemplate.findAllById(Arrays.asList("trader1", "trader2"), Trader.class);
```

```java
List<Trader> allTraders = this.datastoreTemplate.findAll(Trader.class);
```

--------------------------------

### Example Application Output

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-data-multi-sample/README.adoc

This output indicates that both Cloud Spanner and Cloud Datastore are being utilized by the application. It shows the state of entities after deletion and saving operations.

```text
Deleting all entities.
The number of Person entities is now: 0
The number of Trader entities is now: 0
Saving one entity with each repository.
The number of Person entities is now: 1
The number of Trader entities is now: 1
```

--------------------------------

### Run Sender and Receiver Applications

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-integration-pubsub-sample/README.adoc

Start the sender and receiver applications using Maven. Ensure you have configured your Google Cloud project and created the Pub/Sub topic and subscription.

```bash
$ mvn spring-boot:run
```

--------------------------------

### Create Runtime Configuration using gcloud CLI

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/config.adoc

Use the gcloud CLI to initialize your Google Cloud project and create a runtime configuration. This example creates a configuration named 'myapp_prod' and sets a variable 'myapp.queue-size'.

```bash
gcloud init # if this is your first Google Cloud SDK run.
gcloud beta runtime-config configs create myapp_prod
gcloud beta runtime-config configs variables set myapp.queue-size 25 --config-name myapp_prod
```

--------------------------------

### Configure Stackdriver JSON Layout for Logback

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/logging.adoc

This Logback configuration example demonstrates how to set up the StackdriverJsonLayout, including setting the project ID and various options for trace and span ID inclusion. Use this for more granular control over log output.

```xml
<configuration >
  <property name="projectId" value="${projectId:-${GOOGLE_CLOUD_PROJECT}}"/>

  <appender name="CONSOLE_JSON" class="ch.qos.logback.core.ConsoleAppender">
    <encoder class="ch.qos.logback.core.encoder.LayoutWrappingEncoder">
      <layout class="com.google.cloud.spring.logging.StackdriverJsonLayout">
        <projectId>${projectId}</projectId>

        <!--<traceIdMdcField>traceId</traceIdMdcField>-->
        <!--<spanIdMdcField>spanId</spanIdMdcField>-->
        <!--<includeTraceId>true</includeTraceId>-->
        <!--<includeSpanId>true</includeSpanId>-->
        <!--<includeLevel>true</includeLevel>-->
        <!--<includeThreadName>true</includeThreadName>-->
        <!--<includeMDC>true</includeMDC>-->
        <!--<includeLoggerName>true</includeLoggerName>-->
        <!--<includeFormattedMessage>true</includeFormattedMessage>-->
        <!--<includeExceptionInMessage>true</includeExceptionInMessage>-->
        <!--<includeContextName>true</includeContextName>-->
        <!--<includeMessage>false</includeMessage>-->
        <!--<includeException>false</includeException>-->
        <!--<serviceContext>

```

--------------------------------

### SpannerTemplate Usage Example

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/spanner.adoc

Demonstrates autowiring and using 'SpannerTemplate' for common Spanner operations like deleting, inserting, and finding entities.

```java
@SpringBootApplication
public class SpannerTemplateExample {

	@Autowired
	SpannerTemplate spannerTemplate;

	public void doSomething() {
		this.spannerTemplate.delete(Trade.class, KeySet.all());
		//...
		Trade t = new Trade();
		//...
		this.spannerTemplate.insert(t);
		//...
		List<Trade> tradesByAction = spannerTemplate.findAll(Trade.class);

```

--------------------------------

### Run a BigQuery Query using Autoconfigured Client

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/bigquery.adoc

Example of how to use the autoconfigured BigQuery client object to execute a SQL query and iterate over the results.

```java
// BigQuery client object provided by our autoconfiguration.
@Autowired
BigQuery bigquery;

public void runQuery() throws InterruptedException {
  String query = "SELECT column FROM table;";
  QueryJobConfiguration queryConfig = 
      QueryJobConfiguration.newBuilder(query).build();

  // Run the query using the BigQuery object
  for (FieldValueList row : bigquery.query(queryConfig).iterateAll()) {
    for (FieldValue val : row) {
      System.out.println(val);
    }
  }
}
```

--------------------------------

### SpannerTemplate and Repository Usage Example

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/spanner.adoc

Demonstrates using SpannerTemplate for inserting data and SpannerRepository for finding and counting entities. Note that deleteAll, findAll, and countByAction are SpannerRepository methods.

```java
public class MyApplication {

	@Autowired
	spannerTemplate;

	@Autowired
	StudentRepository studentRepository;

	public void demo() {

		this.tradeRepository.deleteAll();
		String traderId = "demo_trader";
		Trade t = new Trade();
		t.symbol = stock;
		t.action = action;
		t.traderId = traderId;
		t.price = new BigDecimal("100.0");
		t.shares = 12345.6;
		this.spannerTemplate.insert(t);

		Iterable<Trade> allTrades = this.tradeRepository.findAll();

		int count = this.tradeRepository.countByAction("BUY");

	}

}
```

--------------------------------

### Query by Example with Default Null Handling

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

Find entities matching a User object where null fields are ignored by default. This is useful for basic filtering.

```java
userRepository.findAll(
    Example.of(new User(null, null, "Smith"))

```

--------------------------------

### Create User-Provided Service with Instance Tag

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/cloudfoundry.adoc

Example of creating a user-provided service for Google Cloud Spanner on Cloud Foundry. The '-t "google-spanner"' argument adds an instance tag to identify the service.

```shell
$ cf create-user-provided-service user-spanner-service -t "google-spanner" ...
```

--------------------------------

### Deploy to App Engine Standard Environment

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-trace-sample/README.adoc

Use the Maven App Engine Plug-in to deploy the application to App Engine Standard environment. Ensure you have the Google Cloud SDK installed.

```bash
$ mvn clean package appengine:deploy -Dapp.deploy.projectId=$PROJECT_ID -Dapp.deploy.version=$VERSION
```

--------------------------------

### Enable Automatic Resource Creation with Consumer Group

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/spring-stream.adoc

When automatic resource creation is ON, topics and subscriptions are created. This example enables it, specifies a destination, and sets a consumer group to avoid anonymous subscriptions.

```properties
spring.cloud.stream.bindings.{CONSUMER_NAME}.destination=myEvents
spring.cloud.stream.gcp.pubsub.bindings.{CONSUMER_NAME}.consumer.auto-create-resources=true

# specify consumer group, and avoid anonymous consumer group generation
spring.cloud.stream.bindings.{CONSUMER_NAME}.group=consumerGroup1
```

--------------------------------

### Import Logback JSON Appender Configuration

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/logging.adoc

Include this XML snippet in your Logback configuration to enable the JSON console appender. This is the basic setup for logging JSON entries to the console.

```xml
<configuration>
  <include resource="com/google/cloud/spring/logging/logback-json-appender.xml" />

  <root level="INFO">
    <appender-ref ref="CONSOLE_JSON" />
  </root>
</configuration>
```

--------------------------------

### Build and Run the Sample

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-pubsub-sample/README.adoc

Build the project using Maven and run the Spring Boot application.

```bash
$ mvn clean install
$ mvn spring-boot:run
```

--------------------------------

### Spring Data JPA with Google Cloud SQL

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/sql.adoc

Example demonstrating Spring Data JPA integration with Google Cloud SQL. This setup is suitable for applications requiring relational database access through JPA.

```java
This is a placeholder for actual code. The source provides links to GitHub repositories and codelabs for detailed examples, rather than inline code snippets.
```

--------------------------------

### Run Sample with Maven

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-spanner-r2dbc-samples/README.adoc

Execute the sample application using Maven, providing necessary Cloud Spanner instance, database, and GCP project properties.

```bash
mvn spring-boot:run -Dspring-boot.run.jvmArguments="-Dspanner.instance=[SPANNER-INSTANCE] -Dspanner.database=[SPANNER-DATABASE] -Dgcp.project=GCP-PROJECT"
```

--------------------------------

### Switch to PostgreSQL Starter in pom.xml

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-data-jpa-sample/README.adoc

To use PostgreSQL instead of MySQL, comment out the MySQL starter dependency and uncomment the PostgreSQL starter dependency in your pom.xml.

```xml
<dependency>
    <groupId>com.google.cloud</groupId>
    <artifactId>spring-cloud-gcp-starter-sql-postgresql</artifactId>
</dependency>
```

--------------------------------

### Run Showcase Unit Tests

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-generator/README.md

Compile and run handwritten unit tests for the generated `showcase-spring-starter` module by navigating to its directory and executing `mvn verify`.

```bash
cd showcase/showcase-spring-starter && mvn verify
```

--------------------------------

### Create Runtime Configuration

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-config-sample/README.adoc

Use the Google Cloud SDK to create a configuration for your application.

```bash
$ gcloud beta runtime-config configs create myapp_prod
```

--------------------------------

### Install Spring Cloud GCP Generator Artifacts

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-generator/scripts/resources/googleapis_modification_string.txt

Installs the Spring Cloud GCP generator artifact and other gRPC Java artifacts. Configure `fail_on_missing_checksum` for local development. Ensure repositories are correctly set for artifact retrieval.

```python
_spring_cloud_generator_version = "8.0.4-SNAPSHOT" # {x-version-update:spring-cloud-gcp:current}

maven_install(
    artifacts = [
      "com.google.cloud:spring-cloud-generator:" + _spring_cloud_generator_version,
      ] + \
      IO_GRPC_GRPC_JAVA_ARTIFACTS,
    generate_compat_repositories = True,
    #Update this False for local development
    fail_on_missing_checksum = False,
    repositories = [
        "m2Local",
        "https://repo.maven.apache.org/maven2/",
    ]
)

```

--------------------------------

### Create Local Configuration File

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-pubsub-bus-config-sample/README.adoc

Create a properties file in the designated local configuration directory to provide initial configuration values.

```bash
echo 'example.message = message from the local filesystem' > /tmp/config/application.properties
```

--------------------------------

### Add Cloud Vision and Storage Starters (Maven)

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/vision.adoc

Include both Maven dependencies for projects requiring OCR on documents, as the storage starter is necessary for writing OCR output files to Google Cloud Storage.

```xml
<dependency>
  <groupId>com.google.cloud</groupId>
  <artifactId>spring-cloud-gcp-starter-vision</artifactId>
</dependency>
<dependency>
  <groupId>com.google.cloud</groupId>
  <artifactId>spring-cloud-gcp-starter-storage</artifactId>
</dependency>
```

--------------------------------

### Update Configuration Variables

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-config-sample/README.adoc

Update existing configuration variables using the Google Cloud SDK after initial setup.

```bash
$ gcloud beta runtime-config configs variables set \
  myapp.queue-size 200 \
  --config-name myapp_prod
```

```bash
$ gcloud beta runtime-config configs variables set \
  myapp.feature-x-enabled false \
  --config-name myapp_prod
```

--------------------------------

### GQL Key-Literal for Item with Ancestor

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

An example of a GQL key-literal representation for an Item, showing how it includes the parent ShoppingOrder ID.

```text
Key(orders, '12345', purchased_item, 'eggs')
```

--------------------------------

### Maven Build Command

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-sql-mysql-sample/README.adoc

Run this command to build the project after setting up dependencies.

```bash
$ mvn clean install
```

--------------------------------

### Album Class Definition

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

A simple POJO representing an Album, used in the Singer class example for custom type conversion.

```java
public class Album {
	String albumName;

	LocalDate date;
}
```

--------------------------------

### Retrieve All Trades via REST

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-data-spanner-repository-sample/README.adoc

Example curl command to retrieve all 'Trade' objects from the repository using the REST endpoint.

```bash
curl http://localhost:8080/trades
```

--------------------------------

### Build and Run Spring Boot Application

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-kms-sample/README.adoc

Commands to build the project using Maven and then run the Spring Boot application. Ensure you are in the directory containing the sample's pom.xml file.

```bash
$mvn clean install
```

```bash
$mvn spring-boot:run
```

--------------------------------

### Add Cloud Vision and Storage Starters (Gradle)

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/vision.adoc

Include both Gradle dependencies for projects requiring OCR on documents, as the storage starter is necessary for writing OCR output files to Google Cloud Storage.

```gradle
dependencies {
  implementation("com.google.cloud:spring-cloud-gcp-starter-vision")
  implementation("com.google.cloud:spring-cloud-gcp-starter-storage")
}
```

--------------------------------

### Singer POJO with Album Field

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

Defines a Singer POJO with a custom Album field. This serves as an example for custom type conversion.

```java
@Entity
public class Singer {

	@Id
	String singerId;

	String name;

	Album album;
}
```

--------------------------------

### Datastore Entity Mapping Example

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

Defines a Datastore entity with ID, fields, and a transient field. Fields annotated with @Transient are ignored.

```java
@Entity(name = "traders")
public class Trader {

	@Id
	@Field(name = "trader_id")
	String traderId;

	String firstName;

	String lastName;

	@Transient
	Double temporaryNumber;
}
```

--------------------------------

### JSON Convertible Class Definition (Java)

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/pubsub.adoc

Example of a class that can be automatically serialized and deserialized to JSON by Pub/Sub when using a configured PubSubMessageConverter.

```java
include::{project-root}/spring-cloud-gcp-autoconfigure/src/test/java/com/google/cloud/spring/autoconfigure/pubsub/it/PubSubTemplateDocumentationIntegrationTests.java[tag=json_convertible_class]
```

--------------------------------

### Add Cloud Natural Language Starter Dependency

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-generator/spring-cloud-previews-template/README.md

To use the starter for Cloud Natural Language, add this dependency to your pom.xml. Ensure you use the preview version tag.

```xml
  <dependency>
    <groupId>com.google.cloud</groupId>
    <artifactId>google-cloud-language-spring-starter</artifactId>
    <version>{starters-version}-preview</version>
  </dependency>
```

--------------------------------

### Sample Parameter Value

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-parametermanager-sample/README.adoc

An example of a parameter value stored in Parameter Manager, shown as a JSON object. This value is injected into the Spring application.

```yaml
applicationParameter: {"message": "Hello World from GCP PM!!"}
```

--------------------------------

### Deploy to App Engine

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-logging-sample/README.adoc

Package and deploy the application to Google App Engine. Replace placeholders with your project ID and desired version.

```bash
mvn clean package appengine:deploy -Dapp.deploy.projectId=$PROJECT_ID -Dapp.deploy.version=$VERSION
```

--------------------------------

### Create Google Parameter Manager Resources

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/parameter.adoc

Use the gcloud CLI to initialize your Google Cloud SDK, create a parameter, and then create a version for that parameter. The parameter name and version should correspond to your application's name and active profile.

```bash
$ gcloud init # if this is your first Google Cloud SDK run.

$ gcloud parametermanager parameters create myapp --location=global --parameter-format=JSON

$ gcloud parametermanager parameters versions create prod --parameter=myapp --location=global --payload-data="{\"myapp.username\":\"test-user\",\"myapp.password\":\"test-password\"}"
```

--------------------------------

### Create Trade via REST

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-data-spanner-repository-sample/README.adoc

Example curl command to create a new 'Trade' object by sending a JSON payload to the REST endpoint.

```bash
curl -XPOST -H"Content-Type: application/json" -d@test.json http://localhost:8080/trades/
```

--------------------------------

### Disable Automatic Resource Creation

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/spring-stream.adoc

When automatic resource creation is OFF, topics and subscriptions are not created by the binder. This example shows disabling it and setting the destination.

```properties
spring.cloud.stream.bindings.{CONSUMER_NAME}.destination=myEvents
spring.cloud.stream.gcp.pubsub.bindings.{CONSUMER_NAME}.consumer.auto-create-resources=false
```

--------------------------------

### Named Queries from Properties File

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

Demonstrates how to define queries in a properties file and reference them by interface and method name.

```properties
Trader.fetchByName=SELECT * FROM traders WHERE name = @tag0
```

```APIDOC
## List<Trader> fetchByName(String name)

### Description
Retrieves a list of traders matching the provided name, as defined in the `datastore-named-queries.properties` file.

### Method
N/A (This is a repository method signature)

### Endpoint
N/A

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```java
// Example usage within a service or controller
List<Trader> traders = traderRepository.fetchByName("Alice");
```

### Response
#### Success Response
- **List<Trader>** - A list of Trader objects matching the query.

#### Response Example
```json
[
  {
    "id": "123",
    "name": "Alice",
    "email": "alice@example.com"
  }
]
```

```

--------------------------------

### Gradle Dependency for Spring Boot Starter Data Spanner

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/spanner.adoc

Use this dependency for a Spring Boot auto-configuration setup for Spring Data Spanner.

```gradle
dependencies {
    implementation("com.google.cloud:spring-cloud-gcp-starter-data-spanner")
}
```

--------------------------------

### Run Sample Locally with Maven

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-security-iap-sample/README.adoc

Execute this command to run the Spring Boot application locally. Configure `spring.cloud.gcp.security.iap.audience` in `application.properties` for testing.

```bash
mvn clean spring-boot:run
```

--------------------------------

### Maven Dependency for Spring Boot Starter Data Spanner

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/spanner.adoc

Use this dependency for a Spring Boot auto-configuration setup for Spring Data Spanner.

```xml
<dependency>
    <groupId>com.google.cloud</groupId>
    <artifactId>spring-cloud-gcp-starter-data-spanner</artifactId>
</dependency>
```

--------------------------------

### Run Spring Boot Application with Maven

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-data-firestore-sample/README.adoc

Execute this command to build and run the Spring Boot application. Ensure you are in the same directory as the sample's pom.xml.

```bash
mvn spring-boot:run
```

--------------------------------

### Datastore Custom Conversions Configuration

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

Configures custom Datastore conversions by providing Converter beans. This setup is necessary for custom type handling.

```java
@Configuration
public class ConverterConfiguration {
	@Bean
	public DatastoreCustomConversions datastoreCustomConversions() {
		return new DatastoreCustomConversions(
				Arrays.asList(
						ALBUM_STRING_CONVERTER,
						STRING_ALBUM_CONVERTER));
	}
}

```

--------------------------------

### Create a Parameter Version with Google Cloud SDK

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-parameter-sample/README.adoc

After creating a parameter, create a version with specific payload data. This command associates a configuration payload with a parameter.

```bash
$ gcloud beta parametermanager parameters versions create prod --parameter=myapp --location=global --payload-data="{\"myapp.username\":\"test-user\",\"myapp.password\":\"test-password\"}"
```

--------------------------------

### Datastore Key Mapping Example

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

Maps a POJO to a Datastore entity with a specified kind and defines the ID field using @Id and @Field annotations.

```java
@Entity(name = "trades")
public class Trade {
	@Id
	@Field(name = "trade_id")
	String tradeId;

	@Field(name = "trader_id")
	String traderId;

	String action;

	Double price;

	Double shares;

	String symbol;
}
```

--------------------------------

### Create a Pub/Sub Topic

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/pubsub.adoc

Use the `PubSubAdmin` to create a new Google Cloud Pub/Sub topic. Provide the topic name as a string argument.

```java
public void newTopic() {
    pubSubAdmin.createTopic("topicName");
}
```

--------------------------------

### Create Cloud Spanner Instance (Emulator)

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-data-spanner-template-sample/README.adoc

Command to create a Cloud Spanner instance for local emulator testing.

```bash
gcloud spanner instances create spring-demo --config=emulator-config --description="Test Instance" --nodes=1
```

--------------------------------

### Create Google Cloud Storage Bucket

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-storage-resource-sample/README.adoc

Use the `gsutil` command to create a new bucket in Google Cloud Storage. Ensure the Cloud SDK is configured.

```bash
$ BUCKET=spring-bucket-$USER
$ gcloud storage buckets create gs://$BUCKET
```

--------------------------------

### Run Local Generation Script

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-generator/README.md

Execute the local generation script `generate.sh` from the `spring-cloud-generator` directory. Ensure Java 17 and other required tools are installed.

```bash
bash scripts/generate.sh
```

--------------------------------

### Build Project with Maven

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-pubsub-bus-config-sample/README.adoc

Compile and package the Spring Cloud GCP project using Maven.

```bash
mvn clean install
```

--------------------------------

### Define Datastore Repository Interface

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

Example of defining a Spring Data Repository interface for Datastore, specifying the domain type (Trader) and its key type (String).

```java
public interface TraderRepository extends DatastoreRepository<Trader, String> {
}
```

--------------------------------

### Add Cloud Vision Starter Dependency (Maven)

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/vision.adoc

Include this Maven dependency to enable Cloud Vision autoconfiguration and client objects.

```xml
<dependency>
  <groupId>com.google.cloud</groupId>
  <artifactId>spring-cloud-gcp-starter-vision</artifactId>
</dependency>
```

--------------------------------

### Retrieve Specific Trade via REST

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-data-spanner-repository-sample/README.adoc

Example curl command to retrieve a specific 'Trade' object by its trader and trade IDs using the REST endpoint.

```bash
curl http://localhost:8080/trades/<trader_id>,<trade_id>
```

--------------------------------

### Use Datastore Repository in Application

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

Shows how to autowire and use a DatastoreRepository to perform basic CRUD operations like deleteAll, save, findAll, and count.

```java
public class MyApplication {

	@Autowired
	TraderRepository traderRepository;

	public void demo() {

		this.traderRepository.deleteAll();
		String traderId = "demo_trader";
		Trader t = new Trader();
		t.traderId = traderId;
		this.tradeRepository.save(t);

		Iterable<Trader> allTraders = this.traderRepository.findAll();

		int count = this.traderRepository.count();
	}

}
```

--------------------------------

### Firestore Operations Template Example

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/firestore.adoc

Illustrates using FirestoreOperations (typically autowired as FirestoreTemplate) for common database operations like saving, finding all, and deleting all entities.

```java
@SpringBootApplication
public class FirestoreTemplateExample {

	@Autowired
	FirestoreOperations firestoreOperations;

	public Mono<User> createUsers() {
		return this.firestoreOperations.save(new User("Alice", 29))
			.then(this.firestoreOperations.save(new User("Bob", 60)));
	}

	public Flux<User> findUsers() {
		return this.firestoreOperations.findAll(User.class);
	}

	public Mono<Long> removeAllUsers() {
		return this.firestoreOperations.deleteAll(User.class);
	}
}
```

--------------------------------

### Manually Restart SmartLifecycle Beans on Refresh

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/core.adoc

When using `@RefreshScope` with `SmartLifecycle` beans, manually stop and start them upon detecting a `RefreshScopeRefreshedEvent` to ensure proper operation.

```java
@Autowired
private PubSubInboundChannelAdapter pubSubAdapter;

@EventListener(RefreshScopeRefreshedEvent.class)
public void onRefreshScope(RefreshScopeRefreshedEvent event) {
  this.pubSubAdapter.stop();
  this.pubSubAdapter.start();
}
```

--------------------------------

### Add Parameter Manager Starter Dependency (Gradle)

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/parametermanager.adoc

Include the starter dependency in your Gradle project to enable Parameter Manager integration.

```gradle
dependencies {
  implementation("com.google.cloud:spring-cloud-gcp-starter-parametermanager")
}
```

--------------------------------

### Customize Pub/Sub Header Mapping

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/spring-integration-pubsub.adoc

Provides an example of customizing outbound header mapping for Pub/Sub messages using `PubSubHeaderMapper`. This allows filtering headers based on patterns.

```java
PubSubMessageHandler adapter = ...
...
PubSubHeaderMapper headerMapper = new PubSubHeaderMapper();
headerMapper.setOutboundHeaderPatterns("!foo", "!bar", "!prefix_*", "*");
adapter.setHeaderMapper(headerMapper);
```

--------------------------------

### Creating a topic

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/pubsub.adoc

Use the `PubSubAdmin` to create a new topic in Google Cloud Pub/Sub. Provide the desired topic name as a string.

```APIDOC
## Creating a topic

### Description
Use the `PubSubAdmin` to create a new topic in Google Cloud Pub/Sub. Provide the desired topic name as a string.

### Method Signature
```java
public Topic createTopic(String topicName)
```

### Example Usage
```java
public void newTopic() {
    pubSubAdmin.createTopic("topicName");
}
```
```

--------------------------------

### Generate and Execute Spanner Table DDL

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/spanner.adoc

Use `SpannerSchemaUtils` to get DDL statements for interleaved hierarchies and `SpannerDatabaseAdminTemplate` to execute them, creating tables and the database if they don't exist.

```java
@Autowired
SpannerSchemaUtils schemaUtils;

@Autowired
SpannerDatabaseAdminTemplate databaseAdmin;
...

// Get the create statmenets for all tables in the table structure rooted at Singer
List<String> createStrings = this.schemaUtils.getCreateTableDdlStringsForInterleavedHierarchy(Singer.class);

// Create the tables and also create the database if necessary
this.databaseAdmin.executeDdlStrings(createStrings, true);

```

--------------------------------

### Add Parameter Manager Starter Dependency (Maven)

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/parametermanager.adoc

Include the starter dependency in your Maven project to enable Parameter Manager integration.

```xml
<dependency>
  <groupId>com.google.cloud</groupId>
  <artifactId>spring-cloud-gcp-starter-parametermanager</artifactId>
</dependency>
```

--------------------------------

### Declarative Filtering with @Where Annotation

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/spanner.adoc

Apply the `@Where` annotation to an entity or interleaved property to specify an SQL WHERE clause for filtering data during fetching. This example filters `Participant` records to only include active ones.

```java
@Table(name = "participants")
public class Participant {
  //...
  boolean active;
  //...
}

@Table(name = "agreements")
public class Agreement {
  //...
  @Interleaved
  @Where("active = true")
  List<Participant> participants;
  Person person;
  //...
}

```

--------------------------------

### Send a Message via Web Interface

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-integration-pubsub-sample/README.adoc

Access the web application at http://localhost:8080, enter a message, and submit it to publish to the Pub/Sub topic.

```bash
http://localhost:8080
```

--------------------------------

### Create a Pub/Sub Subscription

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/pubsub.adoc

Create a Google Cloud Pub/Sub subscription using `PubSubAdmin.createSubscription()`. Specify the subscription name, topic name, and optionally ack deadline and push endpoint.

```java
public Subscription newSubscription() {
    return pubSubAdmin.createSubscription("subscriptionName", "topicName", 15);
}
```

--------------------------------

### Query by Example Including Null Values

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/datastore.adoc

Find entities matching a User object, explicitly including null fields in the filter. Use this when null values should be part of the query criteria.

```java
userRepository.findAll(
    Example.of(new User(null, null, "Smith"), ExampleMatcher.matching().withIncludeNullValues())

```

--------------------------------

### Default Secret Value Example

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/secretmanager.adoc

Illustrates using a default value with the @Value annotation when a secret is not found in Secret Manager. The default is used if the secret name is not a valid application property.

```java
@Value("${${sm@application-fake}:DEFAULT}")
```

--------------------------------

### Spring Cloud GCP Parameter Starter Configuration

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/spring-cloud-gcp-samples/spring-cloud-gcp-parameter-sample/README.adoc

Configure your Spring Boot application to use the Parameter Starter by enabling it and setting the application name and active profile in bootstrap.properties.

```properties
spring.cloud.gcp.parameter.enabled=true
spring.application.name=myapp

#default profile = default
spring.profiles.active=prod
```

--------------------------------

### Add Cloud Vision Starter Dependency (Gradle)

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/vision.adoc

Include this Gradle dependency to enable Cloud Vision autoconfiguration and client objects.

```gradle
dependencies {
  implementation("com.google.cloud:spring-cloud-gcp-starter-vision")
}
```

--------------------------------

### Query with Limits and Offsets

Source: https://github.com/googlecloudplatform/spring-cloud-gcp/blob/main/docs/src/main/asciidoc/spanner.adoc

Apply limits and offsets to SQL queries to control the number of rows returned and the starting point of the result set. This is equivalent to SQL LIMIT and OFFSET clauses.

```java
SpannerQueryOptions spannerQueryOptions = new SpannerQueryOptions().setLimit(2).setOffset(3);
List<Trade> trades = this.spannerTemplate.query(Trade.class, Statement.of("SELECT * FROM trades"), spannerQueryOptions);
```