Spring Boot

https://docs.spring.io/spring-boot
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### Example response for GET /actuator/startup

Source: https://docs.spring.io/spring-boot/api/rest/actuator/startup.html

Example HTTP response showing the JSON structure returned by a GET request to /actuator/startup. It includes springBootVersion, timeline startTime, and an array of startup step events.

```http
HTTP/1.1 200 OK
Content-Type: application/vnd.spring-boot.actuator.v3+json
Content-Length: 889

{
  "springBootVersion" : "4.1.1",
  "timeline" : {
    "events" : [ {
      "duration" : "PT0.000004838S",
      "endTime" : "2026-08-17T10:45:08.847823463Z",
      "startTime" : "2026-08-17T10:45:08.847818625Z",
      "startupStep" : {
        "id" : 3,
        "name" : "spring.beans.instantiate",
        "parentId" : 2,
        "tags" : [ {
          "key" : "beanName",
          "value" : "homeController"
        } ]
      }
    }, {
      "duration" : "PT0.000016421S",
      "endTime" : "2026-08-17T10:45:08.847828022Z",
      "startTime" : "2026-08-17T10:45:08.847811601Z",
      "startupStep" : {
        "id" : 2,
        "name" : "spring.boot.application.starting",
        "tags" : [ {
          "key" : "mainApplicationClass",
          "value" : "com.example.startup.StartupApplication"
        } ]
      }
    } ],
    "startTime" : "2026-08-17T10:45:08.641490840Z"
  }
}
```

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

### Get detailed help for the init command

Source: https://docs.spring.io/spring-boot/cli/using-the-cli.html

Running `spring help init` displays the full usage and options for the init command, including examples for listing capabilities, creating default projects, and creating projects with specific dependencies and build systems.

```shell
$ spring help init
spring init - Initialize a new project using Spring Initializr (start.spring.io)

usage: spring init [options] [location]

Option                       Description
------                       -----------
-a, --artifact-id <String>   Project coordinates; infer archive name (for
                               example 'test')
-b, --boot-version <String>  Spring Boot version (for example '1.2.0.RELEASE')
--build <String>             Build system to use (for example 'maven' or
                               'gradle') (default: maven)
-d, --dependencies <String>  Comma-separated list of dependency identifiers to
                               include in the generated project
--description <String>       Project description
-f, --force                  Force overwrite of existing files
--format <String>            Format of the generated content (for example
                               'build' for a build file, 'project' for a
                               project archive) (default: project)
-g, --group-id <String>      Project coordinates (for example 'org.test')
-j, --java-version <String>  Language level (for example '1.8')
-l, --language <String>      Programming language  (for example 'java')
--list                       List the capabilities of the service. Use it to
                               discover the dependencies and the types that are
                               available
-n, --name <String>          Project name; infer application name
-p, --packaging <String>     Project packaging (for example 'jar')
--package-name <String>      Package name
-t, --type <String>          Project type. Not normally needed if you use --
                               build and/or --format. Check the capabilities of
                               the service (--list) for more details
--target <String>            URL of the service to use (default: https://start.
                               spring.io)
-v, --version <String>       Project version (for example '0.0.1-SNAPSHOT')
-x, --extract                Extract the project archive. Inferred if a
                               location is specified without an extension

examples:

    To list all the capabilities of the service:
        $ spring init --list

    To creates a default project:
        $ spring init

    To create a web my-app.zip:
        $ spring init -d=web my-app.zip

    To create a web/data-jpa gradle project unpacked:
        $ spring init -d=web,jpa --build=gradle my-dir

```

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

### start() - WebServer

Source: https://docs.spring.io/spring-boot/api/java/index-files/index-19.html

Starts the web server.

```APIDOC
## start()

### Description
Starts the web server.

### Method
start()

### Interface
org.springframework.boot.web.server.WebServer

### Parameters
None

### Returns
void
```

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

### Classpath Index File Example

Source: https://docs.spring.io/spring-boot/specification/executable-jar/nested-jars.html

Shows the format of BOOT-INF/classpath.idx. Each line starts with dash space and the jar names are in double quotes. The order determines classpath ordering when running with java -jar.

```none
- "BOOT-INF/lib/dependency2.jar"
- "BOOT-INF/lib/dependency1.jar"
```

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

### start()

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/web/server/WebServer.html

Starts the web server. Calling this method on an already started server has no effect. Throws WebServerException if the server cannot be started.

```APIDOC
## start()

### Description
Starts the web server. Calling this method on an already started server has no effect.

### Method
void start() throws WebServerException

### Parameters
None

### Throws
- **WebServerException** - if the server cannot be started

### Response
No return value.
```

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

### WebClient example in Kotlin

Source: https://docs.spring.io/spring-boot/reference/io/rest-client.html

Kotlin version of the WebClient example, using the same pre-configured WebClient.Builder bean and a similar GET request to retrieve a Mono<Details>.

```kotlin
import org.springframework.stereotype.Service
import org.springframework.web.reactive.function.client.WebClient
import reactor.core.publisher.Mono

@Service
class MyService(webClientBuilder: WebClient.Builder) {

	private val webClient: WebClient

	init {
		webClient = webClientBuilder.baseUrl("https://example.org").build()
	}

	fun someRestCall(name: String): Mono<Details> {
		return webClient.get().uri("/{name}/details", name)
				.retrieve().bodyToMono(Details::class.java)
	}

}
```

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

### start(LogLevel, List) - DockerCompose

Source: https://docs.spring.io/spring-boot/api/java/index-files/index-19.html

Run `docker compose start` to start services.

```APIDOC
## start(LogLevel, List)

### Description
Run `docker compose start` to start services.

### Method
start(LogLevel, List)

### Interface
org.springframework.boot.docker.compose.core.DockerCompose

### Parameters
- **logLevel** (LogLevel) - Required - The log level.
- **services** (List) - Required - The list of services to start.

### Returns
void
```

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

### START - StartCommand

Source: https://docs.spring.io/spring-boot/api/java/index-files/index-19.html

Enum constant indicating to start using `docker compose start`.

```APIDOC
## START

### Description
Start using `docker compose start`.

### Enum Class
org.springframework.boot.docker.compose.lifecycle.StartCommand

### Enum Constant
START
```

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

### Property ordering example 2 (Properties)

Source: https://docs.spring.io/spring-boot/reference/features/external-config.html

Shows the same property ordering example with the import declared after the property. The result is the same as the first example.

```properties
my.property=value
spring.config.import=my.properties
```

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

### hasNotFailed Example

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/test/context/assertj/ApplicationContextAssert.html

Verifies that the application has not failed to start.

```java
assertThat(context).hasNotFailed();
```

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

### startRecording() - BufferingApplicationStartup

Source: https://docs.spring.io/spring-boot/api/java/index-files/index-19.html

Start the recording of steps and mark the beginning of the StartupTimeline.

```APIDOC
## startRecording()

### Description
Start the recording of steps and mark the beginning of the `StartupTimeline`.

### Method
startRecording()

### Class
org.springframework.boot.context.metrics.buffering.BufferingApplicationStartup

### Parameters
None

### Returns
void
```

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

### hasFailed Example

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/test/context/assertj/ApplicationContextAssert.html

Verifies that the application has failed to start.

```java
assertThat(context).hasFailed();
```

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

### starting(ConfigurableBootstrapContext)

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/SpringApplicationRunListener.html

Called immediately when the run method has first started. Can be used for very early initialization.

```APIDOC
## starting(ConfigurableBootstrapContext)

### Description
Called immediately when the run method has first started. Can be used for very early initialization.

### Method
`default void starting(ConfigurableBootstrapContext bootstrapContext)`

### Parameters
- `bootstrapContext` (ConfigurableBootstrapContext) - Required - The bootstrap context

```

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

### Kotlin @PulsarReader example

Source: https://docs.spring.io/spring-boot/reference/messaging/pulsar.html

Kotlin version of the reader endpoint that starts reading from the beginning of 'someTopic'. Uses the same annotation and configuration as the Java example.

```kotlin
import org.springframework.pulsar.annotation.PulsarReader
import org.springframework.stereotype.Component

@Component
class MyBean {

	@PulsarReader(topics = ["someTopic"], startMessageId = "earliest")
	fun processMessage(content: String?) {
		// ...
	}

}
```

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

### start(String name)

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/context/metrics/buffering/BufferingApplicationStartup.html

Starts a new StartupStep with the given name. This method is specified by the ApplicationStartup interface.

```APIDOC
## Method: start(String name)

### Description
Starts a new StartupStep with the given name. This method is specified by the ApplicationStartup interface.

### Signature
`public StartupStep start(String name)`

### Parameters
- **name** (String) - Required - The name of the step.

### Returns
- **StartupStep** - The started step.

```

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

### HTTP Response for GET integrationgraph

Source: https://docs.spring.io/spring-boot/api/rest/actuator/integrationgraph.html

Example HTTP response for a successful GET request to /actuator/integrationgraph. The response includes a JSON body with the graph structure.

```http
HTTP/1.1 200 OK
Content-Type: application/vnd.spring-boot.actuator.v3+json
Content-Length: 1033

{
  "contentDescriptor" : {
    "providerVersion" : "7.1.1",
    "providerFormatVersion" : 1.2,
    "provider" : "spring-integration"
  },
  "links" : [ {
    "from" : 2,
    "to" : 3,
    "type" : "input"
  } ],
  "nodes" : [ {
    "nodeId" : 1,
    "name" : "nullChannel",
    "componentType" : "null-channel",
    "integrationPatternCategory" : "messaging_channel",
    "integrationPatternType" : "null_channel",
    "observed" : false,
    "properties" : { }
  }, {
    "nodeId" : 2,
    "name" : "errorChannel",
    "componentType" : "publish-subscribe-channel",
    "integrationPatternCategory" : "messaging_channel",
    "integrationPatternType" : "publish_subscribe_channel",
    "observed" : false,
    "properties" : { }
  }, {
    "nodeId" : 3,
    "name" : "errorLogger",
    "input" : "errorChannel",
    "componentType" : "logging-channel-adapter",
    "integrationPatternCategory" : "messaging_endpoint",
    "integrationPatternType" : "outbound_channel_adapter",
    "observed" : false,
    "properties" : { }
  } ]
}
```

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

### start(String) - BufferingApplicationStartup

Source: https://docs.spring.io/spring-boot/api/java/index-files/index-19.html

Starts the buffering application startup with a given step name.

```APIDOC
## start(String)

### Description
Starts the buffering application startup with a given step name.

### Method
start(String)

### Class
org.springframework.boot.context.metrics.buffering.BufferingApplicationStartup

### Parameters
- **name** (String) - Required - The name of the startup step.

### Returns
void
```

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

### Spring MVC @RestController example in Java

Source: https://docs.spring.io/spring-boot/reference/web/servlet.html

A typical @RestController that serves JSON data, with endpoints for getting a user, getting user customers, and deleting a user. Uses @RequestMapping, @GetMapping, @DeleteMapping, and @PathVariable.

```java
import java.util.List;

import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/users")
public class MyRestController {

	private final UserRepository userRepository;

	private final CustomerRepository customerRepository;

	public MyRestController(UserRepository userRepository, CustomerRepository customerRepository) {
		this.userRepository = userRepository;
		this.customerRepository = customerRepository;
	}

	@GetMapping("/{userId}")
	public User getUser(@PathVariable Long userId) {
		return this.userRepository.findById(userId).get();
	}

	@GetMapping("/{userId}/customers")
	public List<Customer> getUserCustomers(@PathVariable Long userId) {
		return this.userRepository.findById(userId).map(this.customerRepository::findByUser).get();
	}

	@DeleteMapping("/{userId}")
	public void deleteUser(@PathVariable Long userId) {
		this.userRepository.deleteById(userId);
	}

}
```

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

### PropertiesLauncher.main(String[] args)

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/loader/launch/PropertiesLauncher.html

Static main method to launch the application. It is the entry point when using PropertiesLauncher.

```APIDOC
## [STATIC] PropertiesLauncher.main(String[] args)

### Description
Static main method to launch the application. It is the entry point when using PropertiesLauncher.

### Method
main

### Parameters
- **args** (String[]) - Required - Command line arguments passed to the application.

### Returns
void
```

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

### BufferingApplicationStartup(int capacity)

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/context/metrics/buffering/BufferingApplicationStartup.html

Creates a new buffered ApplicationStartup with a limited capacity and starts the recording of steps.

```APIDOC
## Constructor: BufferingApplicationStartup(int capacity)

### Description
Creates a new buffered ApplicationStartup with a limited capacity and starts the recording of steps.

### Signature
`public BufferingApplicationStartup(int capacity)`

### Parameters
- **capacity** (int) - Required - The configured capacity; once reached, new steps are not recorded.

```

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

### Response from GET /actuator/loggers

Source: https://docs.spring.io/spring-boot/api/rest/actuator/loggers.html

Example HTTP response showing the JSON structure with levels, loggers, and groups.

```http
HTTP/1.1 200 OK
Content-Type: application/vnd.spring-boot.actuator.v3+json
Content-Length: 791

{
  "levels" : [ "OFF", "FATAL", "ERROR", "WARN", "INFO", "DEBUG", "TRACE" ],
  "loggers" : {
    "ROOT" : {
      "configuredLevel" : "INFO",
      "effectiveLevel" : "INFO"
    },
    "com.example" : {
      "configuredLevel" : "DEBUG",
      "effectiveLevel" : "DEBUG"
    }
  },
  "groups" : {
    "test" : {
      "configuredLevel" : "INFO",
      "members" : [ "test.member1", "test.member2" ]
    },
    "web" : {
      "members" : [ "org.springframework.core.codec", "org.springframework.http", "org.springframework.web", "org.springframework.boot.actuate.endpoint.web", "org.springframework.boot.web.servlet.ServletContextInitializerBeans" ]
    },
    "sql" : {
      "members" : [ "org.springframework.jdbc.core", "org.hibernate.SQL", "org.jooq.tools.LoggerListener" ]
    }
  }
}
```

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

### get(ApplicationContext)

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/test/http/server/LocalTestWebServer.html

Returns the LocalTestWebServer instance provided from the ApplicationContext, or null if no local server is started or could be provided.

```APIDOC
## get(ApplicationContext)

### Description
Returns the LocalTestWebServer instance provided from the ApplicationContext, or null if no local server is started or could be provided.

### Method
static

### Signature
`static @Nullable LocalTestWebServer get(ApplicationContext applicationContext)`

### Parameters
- **applicationContext** (ApplicationContext) - Required - The application context from which to obtain the LocalTestWebServer.

### Returns
- **LocalTestWebServer** - The LocalTestWebServer instance, or null if none is available.
```

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

### Start() - DockerComposeProperties.Start

Source: https://docs.spring.io/spring-boot/api/java/index-files/index-19.html

Constructor for the DockerComposeProperties.Start class.

```APIDOC
## Start()

### Description
Constructor for the DockerComposeProperties.Start class.

### Method
Start()

### Class
org.springframework.boot.docker.compose.lifecycle.DockerComposeProperties.Start

### Parameters
None

### Returns
void
```

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

### Spring MVC @RestController example in Kotlin

Source: https://docs.spring.io/spring-boot/reference/web/servlet.html

Kotlin version of the typical @RestController that serves JSON data, with endpoints for getting a user, getting user customers, and deleting a user. Uses @RequestMapping, @GetMapping, @DeleteMapping, and @PathVariable.

```kotlin
import org.springframework.web.bind.annotation.DeleteMapping
import org.springframework.web.bind.annotation.GetMapping
import org.springframework.web.bind.annotation.PathVariable
import org.springframework.web.bind.annotation.RequestMapping
import org.springframework.web.bind.annotation.RestController


@RestController
@RequestMapping("/users")
class MyRestController(private val userRepository: UserRepository, private val customerRepository: CustomerRepository) {

	@GetMapping("/{userId}")
	fun getUser(@PathVariable userId: Long): User {
		return userRepository.findById(userId).get()
	}

	@GetMapping("/{userId}/customers")
	fun getUserCustomers(@PathVariable userId: Long): List<Customer> {
		return userRepository.findById(userId).map(customerRepository::findByUser).get()
	}

	@DeleteMapping("/{userId}")
	fun deleteUser(@PathVariable userId: Long) {
		userRepository.deleteById(userId)
	}

}
```

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

### get(ApplicationContext applicationContext)

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/test/http/server/LocalTestWebServer.html

Returns the LocalTestWebServer instance provided from the ApplicationContext or null if no local server is started or could be provided.

```APIDOC
## get(ApplicationContext applicationContext)

### Description
Returns the `LocalTestWebServer` instance provided from the `ApplicationContext` or `null` if no local server is started or could be provided.

### Method
get(ApplicationContext applicationContext)

### Parameters
- **applicationContext** (ApplicationContext) - Required - The application context

### Returns
- **LocalTestWebServer** - the local test web server or `null`

```

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

### CloudCaptain deployment output example

Source: https://docs.spring.io/spring-boot/how-to/deployment/cloud.html

Example output from the `boxfuse run` command, showing image fusion, AMI creation, instance launch, and successful deployment. The application is accessible at the provided URL.

```none
Fusing Image for myapp-1.0.jar ...
Image fused in 00:06.838s (53937 K) -> axelfontaine/myapp:1.0
Creating axelfontaine/myapp ...
Pushing axelfontaine/myapp:1.0 ...
Verifying axelfontaine/myapp:1.0 ...
Creating Elastic IP ...
Mapping myapp-axelfontaine.boxfuse.io to 52.28.233.167 ...
Waiting for AWS to create an AMI for axelfontaine/myapp:1.0 in eu-central-1 (this may take up to 50 seconds) ...
AMI created in 00:23.557s -> ami-d23f38cf
Creating security group boxfuse-sg_axelfontaine/myapp:1.0 ...
Launching t2.micro instance of axelfontaine/myapp:1.0 (ami-d23f38cf) in eu-central-1 ...
Instance launched in 00:30.306s -> i-92ef9f53
Waiting for AWS to boot Instance i-92ef9f53 and Payload to start at https://52.28.235.61/ ...
Payload started in 00:29.266s -> https://52.28.235.61/
Remapping Elastic IP 52.28.233.167 to i-92ef9f53 ...
Waiting 15s for AWS to complete Elastic IP Zero Downtime transition ...
Deployment completed successfully. axelfontaine/myapp:1.0 is up and running at https://myapp-axelfontaine.boxfuse.io/
```

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

### hasBean example

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/test/context/assertj/ApplicationContextAssert.html

Verifies that the application context contains a bean with the given name. Throws AssertionError if the context did not start or does not contain the bean.

```java
assertThat(context).hasBean("fooBean");
```

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

### Example JAR Structure for Classpath Index

Source: https://docs.spring.io/spring-boot/specification/executable-jar/nested-jars.html

Shows a sample JAR layout used to illustrate the classpath index file. The index file lists jar names in the order they should be added to the classpath.

```none
example.jar
 |
 +-META-INF
 |  +-...
 +-BOOT-INF
    +-classes
    |  +...
    +-lib
       +-dependency1.jar
       +-dependency2.jar
```

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

### doesNotHaveBean by name example

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/test/context/assertj/ApplicationContextAssert.html

Verifies that the application context does not contain a bean with the given name. Throws AssertionError if the context did not start or contains a bean with the name.

```java
assertThat(context).doesNotHaveBean("fooBean");
```

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

### StartupEndpoint(BufferingApplicationStartup) - Constructor

Source: https://docs.spring.io/spring-boot/api/java/index-files/index-19.html

Creates a new StartupEndpoint that will describe the timeline of buffered application startup events.

```APIDOC
## StartupEndpoint(BufferingApplicationStartup)

### Description
Creates a new `StartupEndpoint` that will describe the timeline of buffered application startup events.

### Method
StartupEndpoint(BufferingApplicationStartup)

### Class
org.springframework.boot.actuate.startup.StartupEndpoint

### Parameters
- **bufferingApplicationStartup** (BufferingApplicationStartup) - Required - The buffering application startup.

### Returns
void
```

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

### Retrieve a Single Session with curl

Source: https://docs.spring.io/spring-boot/api/rest/actuator/sessions.html

Makes a GET request to /actuator/sessions/{id} to retrieve a single session by its ID. The example uses the ID '4db5efcc-99cb-4d05-a52c-b49acfbb7ea9'.

```bash
$ curl 'http://localhost:8080/actuator/sessions/4db5efcc-99cb-4d05-a52c-b49acfbb7ea9' -i -X GET
```

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

### Example response for POST /actuator/startup

Source: https://docs.spring.io/spring-boot/api/rest/actuator/startup.html

Example HTTP response showing the JSON structure returned by a POST request to /actuator/startup. It includes springBootVersion, timeline startTime, and an array of startup step events.

```http
HTTP/1.1 200 OK
Content-Type: application/vnd.spring-boot.actuator.v3+json
Content-Length: 889

{
  "springBootVersion" : "4.1.1",
  "timeline" : {
    "events" : [ {
      "duration" : "PT0.000247592S",
      "endTime" : "2026-08-17T10:45:08.812397995Z",
      "startTime" : "2026-08-17T10:45:08.812150403Z",
      "startupStep" : {
        "id" : 1,
        "name" : "spring.beans.instantiate",
        "parentId" : 0,
        "tags" : [ {
          "key" : "beanName",
          "value" : "homeController"
        } ]
      }
    }, {
      "duration" : "PT0.001283604S",
      "endTime" : "2026-08-17T10:45:08.812422711Z",
      "startTime" : "2026-08-17T10:45:08.811139107Z",
      "startupStep" : {
        "id" : 0,
        "name" : "spring.boot.application.starting",
        "tags" : [ {
          "key" : "mainApplicationClass",
          "value" : "com.example.startup.StartupApplication"
        } ]
      }
    } ],
    "startTime" : "2026-08-17T10:45:08.641490840Z"
  }
}
```

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

### HTTP response for job details

Source: https://docs.spring.io/spring-boot/api/rest/actuator/quartz.html

Example response from the GET request, showing the job details and associated triggers. Sensitive data values are sanitized.

```http
HTTP/1.1 200 OK
Content-Type: application/vnd.spring-boot.actuator.v3+json
Content-Length: 594

{
  "className" : "org.springframework.scheduling.quartz.DelegatingJob",
  "data" : {
    "password" : "secret",
    "user" : "admin"
  },
  "description" : "A sample job",
  "durable" : false,
  "group" : "samples",
  "name" : "jobOne",
  "requestRecovery" : false,
  "triggers" : [ {
    "group" : "samples",
    "name" : "every-day",
    "previousFireTime" : "2020-12-04T03:00:00.000Z",
    "nextFireTime" : "2020-12-04T12:00:00.000Z",
    "priority" : 7
  }, {
    "group" : "samples",
    "name" : "3am-weekdays",
    "nextFireTime" : "2020-12-07T03:00:00.000Z",
    "priority" : 3
  } ]
}
```

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

### Retrieve a Single SBOM with curl

Source: https://docs.spring.io/spring-boot/api/rest/actuator/sbom.html

Makes a GET request to /actuator/sbom/{id} to retrieve a specific SBOM. The example retrieves the SBOM named 'application'.

```bash
$ curl 'http://localhost:8080/actuator/sbom/application' -i -X GET

```

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

### Method: initialize(ConfigurableWebApplicationContext)

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/web/servlet/support/ServletContextApplicationContextInitializer.html

Initializes the given application context.

```APIDOC
## Method: initialize(ConfigurableWebApplicationContext)

### Description
Initializes the given application context.

### Signature
`public void initialize(ConfigurableWebApplicationContext applicationContext)`

### Parameters
- `applicationContext` (ConfigurableWebApplicationContext) - Required - The application context to initialize.

### Specified By
`initialize` in interface `ApplicationContextInitializer<ConfigurableWebApplicationContext>`

```

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

### Retrieve Cache by Name with curl

Source: https://docs.spring.io/spring-boot/api/rest/actuator/caches.html

Makes a GET request to /actuator/caches/{name} to retrieve a specific cache by name. The example retrieves the 'cities' cache.

```bash
$ curl 'http://localhost:8080/actuator/caches/cities' -i -X GET
```

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

### initialize

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/logging/log4j2/Log4J2LoggingSystem.html

Fully initializes the logging system with the given configuration location and log file.

```APIDOC
## initialize

### Description
Fully initializes the logging system.

### Method
public void initialize(LoggingInitializationContext initializationContext, @Nullable String configLocation, @Nullable LogFile logFile)

### Parameters
- `initializationContext` (LoggingInitializationContext) - the logging initialization context
- `configLocation` (String) - a log configuration location or `null` if default initialization is required
- `logFile` (LogFile) - the log output file that should be written or `null` for console only output
```

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

### doesNotHaveBean by type example

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/test/context/assertj/ApplicationContextAssert.html

Verifies that the application context (or ancestors) does not contain any beans of the given type. Throws AssertionError if the context did not start or contains any beans of the type.

```java
assertThat(context).doesNotHaveBean(Foo.class);
```

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

### Filter Scanned @Entity Definitions with ManagedClassNameFilter (Kotlin)

Source: https://docs.spring.io/spring-boot/how-to/data-access.html

Kotlin version of the ManagedClassNameFilter example. The filter lambda checks if the class name starts with the customer package prefix.

```kotlin
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
import org.springframework.orm.jpa.persistenceunit.ManagedClassNameFilter

@Configuration(proxyBeanMethods = false)
class MyEntityScanConfiguration {

	@Bean
	fun entityScanFilter() : ManagedClassNameFilter {
		return ManagedClassNameFilter { className ->
			className.startsWith("com.example.app.customer.")
		}
	}
}
```

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

### Create test application launcher with fromApplication (Kotlin)

Source: https://docs.spring.io/spring-boot/reference/features/dev-services.html

Kotlin equivalent of the test launcher, using fromApplication<MyApplication>().run(*args).

```kotlin
import org.springframework.boot.fromApplication

fun main(args: Array<String>) {
	fromApplication<MyApplication>().run(*args)
}
```

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

### applicationStartup(ApplicationStartup applicationStartup)

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/builder/SpringApplicationBuilder.html

Configure the ApplicationStartup to be used with the ApplicationContext for collecting startup metrics.

```APIDOC
## Method: applicationStartup(ApplicationStartup applicationStartup)

### Description
Configure the ApplicationStartup to be used with the ApplicationContext for collecting startup metrics.

### Parameters
- **applicationStartup** (ApplicationStartup) - Required - The ApplicationStartup to use.

### Returns
- **SpringApplicationBuilder** - This builder for chaining.

### Example
```java
new SpringApplicationBuilder(Application.class)
    .applicationStartup(startup)
```
```

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

### hasSingleBean example

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/test/context/assertj/ApplicationContextAssert.html

Verifies that the application context (or ancestors) contains a single bean of the given type. Throws AssertionError if the context did not start, has no beans of the type, or has multiple beans.

```java
assertThat(context).hasSingleBean(Foo.class);
```

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

### Launcher.launch(String[])

Source: https://docs.spring.io/spring-boot/api/java/index-files/index-12.html

Launches the application.

```APIDOC
## launch(String[])

### Description
Launches the application.

### Method
launch(String[])

### Parameters
- **args** (String[]) - The application arguments.
```

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

### WebClient example in Java

Source: https://docs.spring.io/spring-boot/reference/io/rest-client.html

Inject the pre-configured WebClient.Builder bean and create a WebClient with a base URL. Use the WebClient to make a GET request and retrieve a Mono<Details>.

```java
import reactor.core.publisher.Mono;

import org.springframework.stereotype.Service;
import org.springframework.web.reactive.function.client.WebClient;

@Service
public class MyService {

	private final WebClient webClient;

	public MyService(WebClient.Builder webClientBuilder) {
		this.webClient = webClientBuilder.baseUrl("https://example.org").build();
	}

	public Mono<Details> someRestCall(String name) {
		return this.webClient.get().uri("/{name}/details", name).retrieve().bodyToMono(Details.class);
	}

}
```

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

### Retrieve Job Group Overview with curl

Source: https://docs.spring.io/spring-boot/api/rest/actuator/quartz.html

Makes a GET request to /actuator/quartz/jobs/{groupName} to retrieve an overview of jobs in a specific group. The example uses the 'samples' group.

```bash
$ curl 'http://localhost:8080/actuator/quartz/jobs/samples' -i -X GET
```

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

### start() - JettyWebServer

Source: https://docs.spring.io/spring-boot/api/java/index-files/index-19.html

Starts the Jetty web server.

```APIDOC
## start()

### Description
Starts the Jetty web server.

### Method
start()

### Class
org.springframework.boot.jetty.JettyWebServer

### Parameters
None

### Returns
void
```

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

### get(Supplier<? extends ConfigurableWebApplicationContext>)

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/test/context/assertj/AssertableWebApplicationContext.html

Factory method to create a new AssertableWebApplicationContext instance from a supplier that provides a fully configured ConfigurableWebApplicationContext or throws an exception if the context fails to start.

```APIDOC
## get(Supplier<? extends ConfigurableWebApplicationContext>)

### Description
Factory method to create a new `AssertableWebApplicationContext` instance.

### Method
static

### Signature
`static AssertableWebApplicationContext get(Supplier<? extends ConfigurableWebApplicationContext> contextSupplier)`

### Parameters
- `contextSupplier` (Supplier<? extends ConfigurableWebApplicationContext>) - Required - A supplier that will either return a fully configured `ConfigurableWebApplicationContext` or throw an exception if the context fails to start.

### Returns
A `AssertableWebApplicationContext` instance.
```

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

### MyApplication.kt - Spring Boot Hello World (Kotlin)

Source: https://docs.spring.io/spring-boot/tutorial/first-application/index.html

The Kotlin equivalent of the Spring Boot application. It uses the same annotations and the runApplication function to bootstrap the application. The home function returns 'Hello World!' for the root path.

```kotlin
package com.example

import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.runApplication
import org.springframework.web.bind.annotation.RequestMapping
import org.springframework.web.bind.annotation.RestController

@RestController
@SpringBootApplication
class MyApplication {

	@RequestMapping("/")
	fun home() = "Hello World!"

}

fun main(args: Array<String>) {
	runApplication<MyApplication>(*args)
}
```

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

### GET /actuator/startup

Source: https://docs.spring.io/spring-boot/api/rest/actuator/startup.html

Retrieves a snapshot of the application startup steps recorded so far. This operation does not drain the buffer.

```APIDOC
## GET /actuator/startup

### Description
Retrieves a snapshot of the application startup steps recorded so far during the application startup phase. This operation does not drain the buffer.

### Method
GET

### Endpoint
/actuator/startup

### Response
#### Success Response (200)
- **springBootVersion** (String) - Spring Boot version for this application.
- **timeline.startTime** (String) - Start time of the application.
- **timeline.events** (Array) - An array of steps collected during application startup so far.
- **timeline.events.[].startTime** (String) - The timestamp of the start of this event.
- **timeline.events.[].endTime** (String) - The timestamp of the end of this event.
- **timeline.events.[].duration** (String) - The precise duration of this event.
- **timeline.events.[].startupStep.name** (String) - The name of the StartupStep.
- **timeline.events.[].startupStep.id** (Number) - The id of this StartupStep.
- **timeline.events.[].startupStep.parentId** (Number) - The parent id for this StartupStep.
- **timeline.events.[].startupStep.tags** (Array) - An array of key/value pairs with additional step info.
- **timeline.events.[].startupStep.tags[].key** (String) - The key of the StartupStep Tag.
- **timeline.events.[].startupStep.tags[].value** (String) - The value of the StartupStep Tag.

#### Response Example
{
  "springBootVersion" : "4.1.1",
  "timeline" : {
    "events" : [ {
      "duration" : "PT0.000004838S",
      "endTime" : "2026-08-17T10:45:08.847823463Z",
      "startTime" : "2026-08-17T10:45:08.847818625Z",
      "startupStep" : {
        "id" : 3,
        "name" : "spring.beans.instantiate",
        "parentId" : 2,
        "tags" : [ {
          "key" : "beanName",
          "value" : "homeController"
        } ]
      }
    }, {
      "duration" : "PT0.000016421S",
      "endTime" : "2026-08-17T10:45:08.847828022Z",
      "startTime" : "2026-08-17T10:45:08.847811601Z",
      "startupStep" : {
        "id" : 2,
        "name" : "spring.boot.application.starting",
        "tags" : [ {
          "key" : "mainApplicationClass",
          "value" : "com.example.startup.StartupApplication"
        } ]
      }
    } ],
    "startTime" : "2026-08-17T10:45:08.641490840Z"
  }
}
```

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

### get(Supplier<? extends ConfigurableApplicationContext>)

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/test/context/assertj/AssertableApplicationContext.html

Factory method to create a new AssertableApplicationContext instance from a supplier that returns a fully configured ConfigurableApplicationContext or throws an exception if the context fails to start.

```APIDOC
## get(Supplier<? extends ConfigurableApplicationContext>)

### Description
Factory method to create a new `AssertableApplicationContext` instance.

### Method
static

### Signature
`static AssertableApplicationContext get(Supplier<? extends ConfigurableApplicationContext> contextSupplier)`

### Parameters
- `contextSupplier` (Supplier<? extends ConfigurableApplicationContext>) - Required - A supplier that will either return a fully configured `ConfigurableApplicationContext` or throw an exception if the context fails to start.

### Returns
An `AssertableApplicationContext` instance.
```

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

### curl GET request to retrieve trigger details

Source: https://docs.spring.io/spring-boot/api/rest/actuator/quartz.html

Use this curl command to retrieve details of a trigger identified by the group 'samples' and name 'example' from the Spring Boot Actuator endpoint.

```bash
$ curl 'http://localhost:8080/actuator/quartz/triggers/samples/example' -i -X GET
```

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

### logStartupInfo(ConfigurableApplicationContext)

Source: https://docs.spring.io/spring-boot/api/java/index-files/index-12.html

Called to log startup information, subclasses may override to add additional logging. This method is part of the SpringApplication class.

```APIDOC
## logStartupInfo(ConfigurableApplicationContext)

### Description
Called to log startup information, subclasses may override to add additional logging.

### Method
logStartupInfo

### Signature
`logStartupInfo(ConfigurableApplicationContext)`

### Parameters
- **ConfigurableApplicationContext** (ConfigurableApplicationContext) - Required - The application context.

### Return Type
void

### Class
org.springframework.boot.SpringApplication
```

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

### get(Supplier<? extends ConfigurableReactiveWebApplicationContext>)

Source: https://docs.spring.io/spring-boot/api/java/org/springframework/boot/test/context/assertj/AssertableReactiveWebApplicationContext.html

Factory method to create a new AssertableReactiveWebApplicationContext instance. The supplier must return a fully configured context or throw an exception if the context fails to start.

```APIDOC
## get(Supplier<? extends ConfigurableReactiveWebApplicationContext>)

### Description
Factory method to create a new `AssertableReactiveWebApplicationContext` instance.

### Method
static

### Signature
`static AssertableReactiveWebApplicationContext get(Supplier<? extends ConfigurableReactiveWebApplicationContext> contextSupplier)`

### Parameters
- `contextSupplier` (Supplier<? extends ConfigurableReactiveWebApplicationContext>) - Required - A supplier that will either return a fully configured `ConfigurableReactiveWebApplicationContext` or throw an exception if the context fails to start.

### Returns
- `AssertableReactiveWebApplicationContext` - A new `AssertableReactiveWebApplicationContext` instance.
```

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

### start(BuildRequest) - AbstractBuildLog

Source: https://docs.spring.io/spring-boot/api/java/index-files/index-19.html

Log that a build is starting.

```APIDOC
## start(BuildRequest)

### Description
Log that a build is starting.

### Method
start(BuildRequest)

### Class
org.springframework.boot.buildpack.platform.build.AbstractBuildLog

### Parameters
- **request** (BuildRequest) - Required - The build request.

### Returns
void
```

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

### Initialize a new project with dependencies

Source: https://docs.spring.io/spring-boot/cli/using-the-cli.html

Creates a Maven-based project in a my-project directory using spring-boot-starter-web and spring-boot-starter-data-jpa. The output shows the service URL and extraction path.

```shell
$ spring init --dependencies=web,data-jpa my-project
Using service at https://start.spring.io
Project extracted to '/Users/developer/example/my-project'
```
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