Dropwizard

https://www.dropwizard.io/en/stable/
Admin
Dropwizard is a Java framework for developing ops-friendly, high-performance RESTful web services...
Tokens:88,595
Snippets:724
Trust Score:9.6
Update:1 week ago
Show doc for...
Tokens:
Raw
### Start the Dropwizard Example Application

Source: https://www.dropwizard.io/en/stable/manual/example.html

Starts the server using the example configuration file.

```bash
java -jar target/dropwizard-example-5.0.0-SNAPSHOT.jar server example.yml
```

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

### Build the Dropwizard Example Application with Maven

Source: https://www.dropwizard.io/en/stable/manual/example.html

Run this command in the project folder to build the application and install dependencies.

```bash
mvn clean install
```

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

### Startup logs for the server command

Source: https://www.dropwizard.io/en/stable/getting-started.html

Example log output when the server starts, showing the Jetty server initialization and the registered resource endpoint.

```text
INFO  [2011-12-03 00:38:32,927] io.dropwizard.core.cli.ServerCommand: Starting hello-world
INFO  [2011-12-03 00:38:32,931] org.eclipse.jetty.server.Server: jetty-7.x.y-SNAPSHOT
INFO  [2011-12-03 00:38:32,936] org.eclipse.jetty.server.handler.ContextHandler: started o.e.j.s.ServletContextHandler{/,null}
INFO  [2011-12-03 00:38:32,999] com.sun.jersey.server.impl.application.WebApplicationImpl: Initiating Jersey application, version 'Jersey: 1.10 11/02/2011 03:53 PM'
INFO  [2011-12-03 00:38:33,041] io.dropwizard.core.setup.Environment:

    GET     /hello-world (com.example.helloworld.resources.HelloWorldResource)

INFO  [2011-12-03 00:38:33,215] org.eclipse.jetty.server.handler.ContextHandler: started o.e.j.s.ServletContextHandler{/,null}
INFO  [2011-12-03 00:38:33,235] org.eclipse.jetty.server.AbstractConnector: Started BlockingChannelConnector@0.0.0.0:8080 STARTING
INFO  [2011-12-03 00:38:33,238] org.eclipse.jetty.server.AbstractConnector: Started SocketConnector@0.0.0.0:8081 STARTING

```

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

### Run Dropwizard Example Application in IDE

Source: https://www.dropwizard.io/en/stable/manual/example.html

Alternative way to start the application from an IDE by specifying the main class and the server command.

```bash
com.example.helloworld.HelloWorldApplication server example.yml
```

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

### ExampleConfiguration implementing DependencyInjectionConfiguration

Source: https://www.dropwizard.io/en/stable/manual/di.html

Example configuration class that implements the DependencyInjectionConfiguration interface. It provides a method to get the user repository class and overrides getSingletons and getNamedProperties to register the repository and resource as singletons and a named property for the database user.

```java
public class ExampleConfiguration extends Configuration implements DependencyInjectionConfiguration {

    protected Class<?> getUserRepository() {
        return UserRepository.class;
    }

    @Override
    public List<Class<?>> getSingletons() {
        final List<Class<?>> result = new ArrayList();
        result.add(getUserRepository());
        result.add(UserResource.class);

        return result;
    }

    @Override
    public List<NamedProperty<? extends Object>> getNamedProperties() {
        final List<NamedProperty<? extends Object>> result = new ArrayList<>();
        result.add(new NamedProperty<>("dbUser", "dummy_db_user", String.class));

        return result;
    }
}
```

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

### Example response for WebApplicationException

Source: https://www.dropwizard.io/en/stable/manual/core.html

Shows the JSON response returned when a GET request to /foobar triggers the WebApplicationException example.

```json
{"code":404,"message":"Collection foobar does not exist"}
```

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

### Startup banner output example

Source: https://www.dropwizard.io/en/stable/manual/core.html

This is an example of the ASCII art banner printed on application startup when a banner.txt file is placed in src/main/resources. It shows the banner text followed by a Jetty server startup log line.

```text
INFO  [2011-12-09 21:56:37,209] io.dropwizard.core.cli.ServerCommand: Starting hello-world
                                                 dP
                                                 88
  .d8888b. dP.  .dP .d8888b. 88d8b.d8b. 88d888b. 88 .d8888b.
  88ooood8  `8bd8'  88'  `88 88'`88'`88 88'  `88 88 88ooood8
  88.  ...  .d88b.  88.  .88 88  88  88 88.  .88 88 88.  ...
  `88888P' dP'  `dP `88888P8 dP  dP  dP 88Y888P' dP `88888P'
                                        88
                                        dP

INFO  [2011-12-09 21:56:37,214] org.eclipse.jetty.server.Server: jetty-7.6.0
...
```

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

### Server configuration example

Source: https://www.dropwizard.io/en/stable/manual/configuration.html

Example YAML configuration for the default server type, setting maxThreads to 1024.

```yaml
server:
  type: default
  maxThreads: 1024

```

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

### GZip configuration example

Source: https://www.dropwizard.io/en/stable/manual/configuration.html

Example YAML configuration for GZip compression, setting bufferSize to 8KiB.

```yaml
server:
  gzip:
    bufferSize: 8KiB

```

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

### Example view renderer configuration (YAML)

Source: https://www.dropwizard.io/en/stable/manual/views.html

Example YAML configuration for the mustache and freemarker renderers. The 'cache: false' and 'strict_syntax: true' keys are specific to the renderers.

```yaml
---
# views: config->mustache
views:
  mustache:
    cache: false
    # views: config->mustache
  freemarker:
    strict_syntax: true

```

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

### Run server command

Source: https://www.dropwizard.io/en/stable/manual/internals.html

Example command to run the Dropwizard server with a configuration file.

```bash
java -jar target/hello-world-0.0.1-SNAPSHOT.jar server hello-world.yml
```

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

### Run database migration for Dropwizard Example

Source: https://www.dropwizard.io/en/stable/manual/example.html

Executes the Liquibase migration defined in /src/main/resources/migrations.xml, creating the table schema.

```bash
java -jar target/dropwizard-example-5.0.0-SNAPSHOT.jar db migrate example.yml
```

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

### Servlet Health Responder Configuration Example

Source: https://www.dropwizard.io/en/stable/manual/configuration.html

Shows how to configure the health responder to use the servlet implementation, with cache control settings.

```yaml
health:
  responder:
    type: servlet
    cacheControlEnabled: true
    cacheControlValue: "no-store"

```

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

### Database YAML configuration

Source: https://www.dropwizard.io/en/stable/manual/configuration.html

Example YAML configuration for a database connection using PostgreSQL driver.

```yaml
database:
  driverClass : org.postgresql.Driver
  url: 'jdbc:postgresql://db.example.com/db-prod'
  user: pg-user
  password: iAMs00perSecrEET
```

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

### Maven Package Build Output

Source: https://www.dropwizard.io/en/stable/getting-started.html

Example output from running mvn package after configuring the JAR plugin. Shows the shaded jar creation and build success.

```text
[INFO] Including org.eclipse.jetty:jetty-util:jar:7.6.0.RC0 in the shaded jar.
[INFO] Including com.google.guava:guava:jar:10.0.1 in the shaded jar.
[INFO] Including com.google.code.findbugs:jsr305:jar:1.3.9 in the shaded jar.
[INFO] Including org.hibernate:hibernate-validator:jar:4.2.0.Final in the shaded jar.
[INFO] Including javax.validation:validation-api:jar:1.0.0.GA in the shaded jar.
[INFO] Including org.yaml:snakeyaml:jar:1.9 in the shaded jar.
[INFO] Replacing original artifact with shaded artifact.
[INFO] Replacing /Users/yourname/Projects/hello-world/target/hello-world-0.0.1-SNAPSHOT.jar with /Users/yourname/Projects/hello-world/target/hello-world-0.0.1-SNAPSHOT-shaded.jar
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 8.415s
[INFO] Finished at: Fri Dec 02 16:26:42 PST 2011
[INFO] Final Memory: 11M/81M
[INFO] ------------------------------------------------------------------------
```

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

### Exception Configuration Example

Source: https://www.dropwizard.io/en/stable/manual/configuration.html

Shows the exception sub-configuration for the JSON layout, setting rootFirst to false, depth to 25, and evaluators to filter packages from the stacktrace.

```yaml
layout:
  type: json
  exception:
    rootFirst: false
    depth: 25
    evaluators: [org.apache]

```

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

### Health Checks Configuration Example

Source: https://www.dropwizard.io/en/stable/manual/configuration.html

Shows how to configure individual health checks with name, type (alive or ready), critical flag, and initial state.

```yaml
health:
  healthChecks:
    - name: file-system
      type: alive
      critical: true
      initialState: true
    - name: database
      type: ready
      critical: false
      initialState: false

```

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

### Create an Authorizer implementing Authorizer<User>

Source: https://www.dropwizard.io/en/stable/manual/upgrade-notes/upgrade-notes-0_9_x.html

Example Authorizer that checks if the user name is 'good-guy' and the role is 'ADMIN'.

```java
public class ExampleAuthorizer implements Authorizer<User> {
  @Override
  public boolean authorize(User user, String role) {
    return user.getName().equals("good-guy") && role.equals("ADMIN");
  }
}

```

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

### YAML configuration for messageQueue

Source: https://www.dropwizard.io/en/stable/manual/core.html

Example YAML snippet showing how to configure the nested messageQueue field with host and port values.

```yaml
messageQueue:
  host: mq.example.com
  port: 5673

```

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

### HibernateBundle setup in application class

Source: https://www.dropwizard.io/en/stable/manual/hibernate.html

Adds a HibernateBundle to the application, specifying the entity class and how to obtain the DataSourceFactory. The bundle is used to create a PersonDAO and register a UserResource.

```java
private final HibernateBundle<ExampleConfiguration> hibernate = new HibernateBundle<ExampleConfiguration>(Person.class) {
    @Override
    public DataSourceFactory getDataSourceFactory(ExampleConfiguration configuration) {
        return configuration.getDataSourceFactory();
    }
};

@Override
public void initialize(Bootstrap<ExampleConfiguration> bootstrap) {
    bootstrap.addBundle(hibernate);
}

@Override
public void run(ExampleConfiguration config, Environment environment) {
    final PersonDAO dao = new PersonDAO(hibernate.getSessionFactory());
    environment.jersey().register(new UserResource(dao));
}
```

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

### JSON Health Response Provider Configuration Example

Source: https://www.dropwizard.io/en/stable/manual/configuration.html

Shows how to configure the health response provider to use the JSON implementation.

```yaml
health:
  responseProvider:
    type: json

```

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

### Example Dropwizard log output

Source: https://www.dropwizard.io/en/stable/manual/core.html

Sample log output showing the format with level, timestamp, logger, and message, including stack trace lines prefixed with '!'.

```text
TRACE [2010-04-06 06:42:35,271] com.example.dw.Thing: Contemplating doing a thing.
DEBUG [2010-04-06 06:42:35,274] com.example.dw.Thing: About to do a thing.
INFO  [2010-04-06 06:42:35,274] com.example.dw.Thing: Doing a thing
WARN  [2010-04-06 06:42:35,275] com.example.dw.Thing: Doing a thing
ERROR [2010-04-06 06:42:35,275] com.example.dw.Thing: This may get ugly.
! java.lang.RuntimeException: oh noes!
! at com.example.dw.Thing.run(Thing.java:16)
!
```

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

### Database configuration YAML

Source: https://www.dropwizard.io/en/stable/manual/hibernate.html

Example YAML configuration for the database, including JDBC driver, credentials, URL, Hibernate dialect, connection pool settings, and a validation query.

```yaml
database:
  # the name of your JDBC driver
  driverClass: org.postgresql.Driver

  # the username
  user: pg-user

  # the password
  password: iAMs00perSecrEET

  # the JDBC URL
  url: jdbc:postgresql://db.example.com/db-prod

  # any properties specific to your JDBC driver:
  properties:
    charSet: UTF-8
    hibernate.dialect: org.hibernate.dialect.PostgreSQLDialect

  # the maximum amount of time to wait on an empty pool before throwing an exception
  maxWaitForConnection: 1s

  # the SQL query to run when validating a connection's liveness
  validationQuery: "/* MyApplication Health Check */ SELECT 1"

  # the minimum number of connections to keep open
  minSize: 8

  # the maximum number of connections to keep open
  maxSize: 32

  # whether or not idle connections should be validated
  checkConnectionWhileIdle: false
```

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

### Executing a GET request

Source: https://www.dropwizard.io/en/stable/manual/upgrade-notes/upgrade-notes-0_8_x.html

Example of executing a GET request with Jersey 2 client in integration tests.

```java
final WebTarget target = ClientBuilder.newClient().target(
        String.format("http://localhost:%d/api/user/1", RULE.getLocalPort()));

final Response response = target
        .request(MediaType.APPLICATION_JSON_TYPE)
        .accept(MediaType.APPLICATION_JSON_TYPE)
        .get();

assertThat(response.getStatus()).isEqualTo(Response.Status.OK.getStatusCode());

final User user = response.readEntity(User.class);
assertThat(user.getId()).isEqualTo(1L);
assertThat(user.getFirstName()).isEqualTo("John");
assertThat(user.getLastName()).isEqualTo("Doe");
```

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

### HelloWorldApplicationStart class

Source: https://www.dropwizard.io/en/stable/getting-started.html

Basic Dropwizard application class that extends Application<HelloWorldConfiguration>. It includes a main method as entry point, overrides getName to return "hello-world", and provides empty initialize and run methods. The run method is currently unimplemented.

```java
package com.example.helloworld;

import io.dropwizard.core.Application;
import io.dropwizard.core.setup.Bootstrap;
import io.dropwizard.core.setup.Environment;

public class HelloWorldApplicationStart extends Application<HelloWorldConfiguration> {
    public static void main(String[] args) throws Exception {
        new HelloWorldApplicationStart().run(args);
    }

    @Override
    public String getName() {
        return "hello-world";
    }

    @Override
    public void initialize(Bootstrap<HelloWorldConfiguration> bootstrap) {
        // nothing to do yet
    }

    @Override
    public void run(HelloWorldConfiguration configuration, Environment environment) {
        // nothing to do yet
    }
}

```

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

### Run the application with the server command and configuration file

Source: https://www.dropwizard.io/en/stable/getting-started.html

Starts the HTTP server by passing the 'server' command and the YAML configuration file. The application listens on ports 8080 and 8081.

```bash
java -jar target/hello-world-0.0.1-SNAPSHOT.jar server hello-world.yml

```

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

### Curl request to /healthcheck endpoint

Source: https://www.dropwizard.io/en/stable/manual/core.html

Send a GET request to /healthcheck on the admin port to run health checks and view results. The example shows a successful response with all healthy.

```bash
$ curl http://dw.example.com:8081/healthcheck
{"deadlocks":{"healthy":true},"database":{"healthy":true}}

```

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

### Resource with getter methods causing additional invocations

Source: https://www.dropwizard.io/en/stable/manual/validation.html

Warns that endpoints with function name starting with 'get', no arguments, and return value validation constraints are additionally invoked whenever a request is processed by the resource.

```java
@Path("/")
public class ValidatedResource {
    private AtomicLong counter = new AtomicLong();

    @GET
    @Path("/foo")
    @NotEmpty
    public String getFoo() {
        counter.getAndIncrement();
        return "";
    }

    @GET
    @Path("/bar")
    public String getBar() {
        return "";
    }
}
```

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

### Application.run() startup sequence

Source: https://www.dropwizard.io/en/stable/manual/internals.html

Simplified implementation of Application.run() showing the bootstrap process: creating Bootstrap, adding built-in commands (server, check), calling initialize(), registering metrics, and running the CLI.

```java
public void run(String... arguments) throws Exception {

  final Bootstrap<T> bootstrap = new Bootstrap<>(this);
  bootstrap.addCommand(new ServerCommand<>(this));
  bootstrap.addCommand(new CheckCommand<>(this));

  initialize(bootstrap); // -- implemented by you; it should call:
        // 1. add bundles (typically being used)
        // 2. add commands (if any)

  // Should be called after `initialize` to give an opportunity to set a custom metric registry
  bootstrap.registerMetrics(); // start tracking some default jvm params…

  // for each cmd, configure parser w/ cmd
  final Cli cli = new Cli(new JarLocation(getClass()), bootstrap, our, err)
  cli.run(arguments);
}
```

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

### Non-JUnit integration test with DropwizardTestSupport

Source: https://www.dropwizard.io/en/stable/manual/testing.html

Use DropwizardTestSupport to manually start and stop the app via its before() and after() methods. It exposes the app's Configuration, Environment, and app object. The example uses ConfigOverride to set a random port when not using a separate testing config file, and builds a Jersey client with JerseyClientBuilder.

```java
public class LoginAcceptanceTest {

    public static final DropwizardTestSupport<TestConfiguration> SUPPORT =
            new DropwizardTestSupport<TestConfiguration>(MyApp.class,
                ResourceHelpers.resourceFilePath("my-app-config.yaml"),
                ConfigOverride.config("server.applicationConnectors[0].port", "0") // Optional, if not using a separate testing-specific configuration file, use a randomly selected port
            );

    @BeforeAll
    public void beforeClass() {
        SUPPORT.before();
    }

    @AfterAll
    public void afterClass() {
        SUPPORT.after();
    }

    @Test
    public void loginHandlerRedirectsAfterPost() {
        Client client = new JerseyClientBuilder(SUPPORT.getEnvironment()).build("test client");

        Response response = client.target(
                 String.format("http://localhost:%d/login", SUPPORT.getLocalPort()))
                .request()
                .post(Entity.json(loginForm()));

        assertThat(response.getStatus()).isEqualTo(302);
    }
}
```

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

### JUnit 5 integration test with DropwizardAppExtension

Source: https://www.dropwizard.io/en/stable/manual/testing.html

Use @ExtendWith(DropwizardExtensionsSupport.class) and a static DropwizardAppExtension to start the app before tests and stop it after. The extension exposes the app's Configuration, Environment, and app object, and its client() method returns a Jersey HTTP client managed by the extension. The example shows a test that posts JSON to /login and asserts a 302 status.

```java
@ExtendWith(DropwizardExtensionsSupport.class)
class LoginAcceptanceTest {

    private static DropwizardAppExtension<TestConfiguration> EXT = new DropwizardAppExtension<>(
            MyApp.class,
            ResourceHelpers.resourceFilePath("my-app-config.yaml")
        );

    @Test
    void loginHandlerRedirectsAfterPost() {
        Client client = EXT.client();

        Response response = client.target(
                 String.format("http://localhost:%d/login", EXT.getLocalPort()))
                .request()
                .post(Entity.json(loginForm()));

        assertThat(response.getStatus()).isEqualTo(302);
    }
}
```

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

### JUnit 5 test with DropwizardClientExtension and PingResource

Source: https://www.dropwizard.io/en/stable/manual/testing.html

Use this JUnit 5 test to verify HTTP client behavior against a JAX-RS test double. The DropwizardClientExtension starts a minimal Dropwizard application with the provided resource, selects a random free port, and stops the application after the test. The example uses java.net.URL#openStream() for simplicity, but you should replace it with your actual HTTP client.

```java
@ExtendWith(DropwizardExtensionsSupport.class)
class CustomClientTest {
    @Path("/ping")
    public static class PingResource {
        @GET
        public String ping() {
            return "pong";
        }
    }

    private static final DropwizardClientExtension EXT = new DropwizardClientExtension(new PingResource());

    @Test
    void shouldPing() throws IOException {
        final URL url = new URL(EXT.baseUri() + "/ping");
        final String response = new BufferedReader(new InputStreamReader(url.openStream())).readLine();
        assertEquals("pong", response);
    }
}

```

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

### Implement Managed interface for RiakClient

Source: https://www.dropwizard.io/en/stable/manual/core.html

Defines a wrapper class that implements Managed, calling start() and stop() on the RiakClient. If start() throws, the application fails to start; if stop() throws, it is logged but shutdown continues.

```java
public class RiakClientManager implements Managed {
    private final RiakClient client;

    public RiakClientManager(RiakClient client) {
        this.client = client;
    }

    @Override
    public void start() throws Exception {
        client.start();
    }

    @Override
    public void stop() throws Exception {
        client.stop();
    }
}

```

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

### @ResponseMetered Example

Source: https://www.dropwizard.io/en/stable/manual/core.html

An example resource method that uses @ResponseMetered to measure the rate of response codes.

```APIDOC
## GET /response-metered

### Description
Returns a 200 OK response, or a 500 Internal Server Error if the 'invalid' query parameter is true. The method is annotated with @ResponseMetered to measure the rate of each response code class.

### Method
GET

### Endpoint
/response-metered

### Parameters
#### Query Parameters
- **invalid** (boolean) - Optional - If true, returns a 500 Internal Server Error.

### Request Example
GET /response-metered?invalid=true

### Response
#### Success Response (200)
- Returns an empty response with status 200 OK.

#### Error Response (500)
- Returns an empty response with status 500 Internal Server Error.
```

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

### Application run method using DependencyInjectionBundle

Source: https://www.dropwizard.io/en/stable/manual/di.html

Shows how to create and run the DependencyInjectionBundle in the application's run method. Note that the example uses 'configuration' but the parameter is named 'config', which may be a typo in the source.

```java
@Override
public void run(ExampleConfiguration config,
                Environment environment) {
    final DependencyInjectionBundle dependencyInjectionBundle = new DependencyInjectionBundle();
    dependencyInjectionBundle.run(configuration, environment);
}
```

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

### @ExceptionMetered Example

Source: https://www.dropwizard.io/en/stable/manual/core.html

An example resource method that uses @ExceptionMetered to measure how often an IOException occurs.

```APIDOC
## GET /exception-metered

### Description
Returns a string, but throws an IOException if the 'splode' query parameter is true. The method is annotated with @ExceptionMetered to measure the rate of exceptions.

### Method
GET

### Endpoint
/exception-metered

### Parameters
#### Query Parameters
- **splode** (boolean) - Optional - If true, throws an IOException.

### Request Example
GET /exception-metered?splode=true

### Response
#### Success Response (200)
- Returns the string "fuh" if splode is false.

#### Response Example
"fuh"
```

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

### JSON Layout Configuration Example

Source: https://www.dropwizard.io/en/stable/manual/configuration.html

Shows the full JSON layout configuration with timestamp format, pretty printing, line separator, included fields, custom field names, additional fields, MDC key filtering, flattening, and exception settings.

```yaml
layout:
  type: json
  timestampFormat: "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
  prettyPrint: false
  appendLineSeparator: true
  includes: [timestamp, threadName, level, loggerName, message, mdc, exception]
  customFieldNames:
    timestamp: "@timestamp"
  additionalFields:
    service-name: "user-service"
  includesMdcKeys: [userId]
  flattenMdc: true
  exception:
    rootFirst: true
    depth: full
    evaluators: [org.apache]

```

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

### ExampleConfiguration with JerseyClientConfiguration

Source: https://www.dropwizard.io/en/stable/manual/client.html

Configuration class that defines a Jersey client configuration bean. Use this to enable Jersey client support in a Dropwizard service.

```java
package com.example;

import com.fasterxml.jackson.annotation.JsonProperty;
import io.dropwizard.Configuration;
import io.dropwizard.client.JerseyClientConfiguration;
import org.hibernate.validator.constraints.NotEmpty;

import javax.validation.Valid;
import javax.validation.constraints.NotEmpty;

public class ExampleConfiguration extends Configuration {
    @Valid
    @NotNull
    private JerseyClientConfiguration jerseyClient = new JerseyClientConfiguration();

    @JsonProperty("jerseyClient")
    public JerseyClientConfiguration getJerseyClientConfiguration() {
        return jerseyClient;
    }

    @JsonProperty("jerseyClient")
    public void setJerseyClientConfiguration(JerseyClientConfiguration jerseyClient) {
        this.jerseyClient = jerseyClient;
    }
}
```

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

### Register ServerLifecycleListener for Jetty started event

Source: https://www.dropwizard.io/en/stable/manual/internals.html

Use env.lifecycle().addServerLifecycleListener() to register a listener that is called after all Managed objects' start() methods have been invoked. The serverStarted(Server server) method is where you can perform actions that require Jetty to be fully started.

```java
env.lifecycle().addServerLifecycleListener(new ServerLifecycleListener() {
    @Override
    public void serverStarted(Server server) {
              /// ... do things here ....
    }
});
```

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

### FreeMarker template example (person.ftl)

Source: https://www.dropwizard.io/en/stable/manual/views.html

Example FreeMarker template that uses the @ftlvariable directive to type the root object. It calls getPerson().getName() and sanitizes the output with ?html.

```ftl
<#-- @ftlvariable name="" type="io.dropwizard.documentation.PersonView" -->
<html lang="en">
<body>
<!-- calls getPerson().getName() and sanitizes it -->
<h1>Hello, ${person.name?html}!</h1>
</body>
</html>

```

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

### Run the application JAR

Source: https://www.dropwizard.io/en/stable/getting-started.html

Executes the built JAR file. Without arguments, it prints usage information showing available commands and options.

```bash
java -jar target/hello-world-0.0.1-SNAPSHOT.jar

```

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

### File appender YAML configuration

Source: https://www.dropwizard.io/en/stable/manual/configuration.html

Example configuration for the file appender. The type must be 'file' and currentLogFilename is required. The example sets archive to true with a date-based archivedLogFilenamePattern and a custom logFormat.

```yaml
logging:
  level: INFO
  appenders:
    - type: file
      currentLogFilename: /var/log/myapplication.log
      threshold: ALL
      queueSize: 512
      discardingThreshold: 0
      archive: true
      archivedLogFilenamePattern: /var/log/myapplication-%d.log
      archivedFileCount: 5
      timeZone: UTC
      logFormat: "%-5p [%d{ISO8601,UTC}] %c: %m%n%dwREx"
      bufferSize: 8KiB
      immediateFlush: true
      filterFactories:
        - type: URI

```

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

### Usage output for the application JAR

Source: https://www.dropwizard.io/en/stable/getting-started.html

Shows the help text printed when the JAR is run without arguments, listing the available 'server' command and options.

```text
usage: java -jar hello-world-0.0.1-SNAPSHOT.jar
       [-h] [-v] {server} ...

positional arguments:
  {server}               available commands

optional arguments:
  -h, --help             show this help message and exit
  -v, --version          show the service version and exit

```

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

### HTTPS connector configuration with key store

Source: https://www.dropwizard.io/en/stable/manual/core.html

Configures an HTTPS application connector on port 8443 using a keystore. The example uses a test keystore from the Dropwizard example project. By default, only secure TLSv1.2 cipher suites are allowed.

```yaml
---
server:
  applicationConnectors:
    - type: https
      port: 8443
      keyStorePath: example.keystore
      keyStorePassword: example
      validateCerts: false

```

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

### Register managed instance in Application.run

Source: https://www.dropwizard.io/en/stable/manual/core.html

Shows how to create a RiakClient and its manager, then register it with environment.lifecycle().manage() so the lifecycle is tied to the server.

```java
public class ManagedApp extends Application<Configuration> {
    @Override
    public void run(Configuration configuration, Environment environment) {
        RiakClient client = new RiakClient();
        RiakClientManager riakClientManager = new RiakClientManager(client);
        environment.lifecycle().manage(riakClientManager);
    }
}

```

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

### Basic Dropwizard resource class with @Path, @GET, @POST

Source: https://www.dropwizard.io/en/stable/manual/core.html

Defines a RESTful resource for a user's notifications, responding to GET and POST on /{user}/notifications with JSON. Uses @PathParam, @QueryParam, @DefaultValue, @NotNull, @Valid, and returns NotificationList or Response. Throws WebApplicationException with 404 if notifications are null.

```java
@Path("/{user}/notifications")
@Produces(MediaType.APPLICATION_JSON)
@Consumes(MediaType.APPLICATION_JSON)
public class NotificationsResource {
    private final NotificationStore store;

    public NotificationsResource(NotificationStore store) {
        this.store = store;
    }

    @GET
    public NotificationList fetch(@PathParam("user") OptionalLong userId,
                                  @QueryParam("count") @DefaultValue("20") OptionalInt count) {
        final List<Notification> notifications = store.fetch(userId.get(), count.get());
        if (notifications != null) {
            return new NotificationList(userId, notifications);
        }
        throw new WebApplicationException(Status.NOT_FOUND);
    }

    @POST
    public Response add(@PathParam("user") OptionalLong userId,
                        @NotNull @Valid Notification notification) {
        final long id = store.add(userId.get(), notification);
        return Response.created(UriBuilder.fromResource(NotificationResource.class)
                                          .build(userId.get(), id))
                       .build();
    }
}
```

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

### Initialize multiple migration bundles with custom names

Source: https://www.dropwizard.io/en/stable/manual/migrations.html

Shows how to add two MigrationsBundle instances with unique names (db1 and db2) in the initialize method, each using a different DataSourceFactory from the configuration.

```java
@Override
public void initialize(Bootstrap<ExampleConfiguration> bootstrap) {
    bootstrap.addBundle(new MigrationsBundle<ExampleConfiguration>() {
        @Override
        public DataSourceFactory getDataSourceFactory(ExampleConfiguration configuration) {
            return configuration.getDb1DataSourceFactory();
        }

        @Override
        public String name() {
            return "db1";
        }
    });

    bootstrap.addBundle(new MigrationsBundle<ExampleConfiguration>() {
        @Override
        public DataSourceFactory getDataSourceFactory(ExampleConfiguration configuration) {
            return configuration.getDb2DataSourceFactory();
        }

        @Override
        public String name() {
            return "db2";
        }
    });
}

```

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

### Configuration File with Environment Variable Substitution

Source: https://www.dropwizard.io/en/stable/manual/core.html

Shows how to reference environment variables in the configuration file. Uses StringSubstitutor syntax, with optional default values using ':-'.

```yaml
mySetting: ${DW_MY_SETTING}
defaultSetting: ${DW_DEFAULT_SETTING:-default value}
```

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

### Define a custom Command subclass (MyCommand)

Source: https://www.dropwizard.io/en/stable/manual/core.html

Extends Command to create a 'hello' command that prints a greeting. The configure method adds a required -u/--user option. The run method prints 'Hello <user>'.

```java
public class MyCommand extends Command {
    public MyCommand() {
        // The name of our command is "hello" and the description printed is
        // "Prints a greeting"
        super("hello", "Prints a greeting");
    }

    @Override
    public void configure(Subparser subparser) {
        // Add a command line option
        subparser.addArgument("-u", "--user")
                .dest("user")
                .type(String.class)
                .required(true)
                .help("The user of the program");
    }

    @Override
    public void run(Bootstrap<?> bootstrap, Namespace namespace) throws Exception {
        System.out.println("Hello " + namespace.getString("user"));
    }
}
```

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

### Enum definition for validation

Source: https://www.dropwizard.io/en/stable/manual/validation.html

Defines an enum Choice with three options used in the endpoint example.

```java
public enum Choice {
    OptionA,
    OptionB,
    OptionC
}
```

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

### YAML configuration file for Hello World

Source: https://www.dropwizard.io/en/stable/getting-started.html

YAML configuration file that specifies the template and defaultName parameters. The template uses a %s placeholder for the name, and defaultName defaults to 'Stranger'.

```yaml
---
template: Hello, %s!
defaultName: Stranger

```

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

### Executing a POST request

Source: https://www.dropwizard.io/en/stable/manual/upgrade-notes/upgrade-notes-0_8_x.html

Example of executing a POST request with Jersey 2 client in integration tests.

```java
final WebTarget target = ClientBuilder.newClient().target(
        String.format("http://localhost:%d/api/user", RULE.getLocalPort()));

final User user = new User(0L, "John", "Doe");

final Response response = target
        .request(MediaType.APPLICATION_JSON_TYPE)
        .accept(MediaType.APPLICATION_JSON_TYPE)
        .post(Entity.json(user));

assertThat(response.getStatus()).isEqualTo(Response.Status.CREATED.getStatusCode());

final URI location = response.getLocation();
assertThat(location).isNotNull();

final String path = location.getPath();
final long newId = Long.parseLong(path.substring(path.lastIndexOf("/") + 1));
assertThat(newId).isGreaterThan(0);
```

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

### DropwizardAppRule class rule

Source: https://www.dropwizard.io/en/stable/manual/upgrade-notes/upgrade-notes-0_8_x.html

The DropwizardAppRule class rule is unchanged in 0.8.x and is used in the integration testing examples below.

```java
@ClassRule
public static final DropwizardAppRule<SportChefConfiguration> RULE =
                    new DropwizardAppRule<>(App.class, "config.yaml");
```
Tokens:
Raw