public interface JokeService {
  String getJoke();
}

@Service
public class JokeServiceRestImpl implements JokeService {

  private final RestTemplate restTemplate;
  
  public JokeServiceRestImpl(RestTemplate restTemplate) { 
    this.restTemplate = restTemplate;
  }

  @Override
  public String getJoke() {
    String url = "http://api.icndb.com/jokes/random";
    ResponseEntity<String> response = 
    restTemplate.getForEntity(url, String.class);
    return response.getBody();
  }
}

@SpringBootApplication
public class JokesApplication {

  // ...
  
  @Bean
  public RestTemplate restTemplate() {
    return new RestTemplate();
  }
}

@SpringBootTest
public class JokeServiceRestImplTest {

  @Autowired
  JokeService jokeService;

  @Test
  public void joke() {
    String jokeText = jokeService.getJoke();
    Assert.assertFalse(jokeText.isEmpty());
        
    boolean jokeContainsChuckName =
      jokeText.contains("Chuck Norris");
    Assert.assertTrue(jokeContainsChuckName);
  }
}

> { "type": "success", "value": { "id": 31, "joke": "Chuck Norris has two speeds: Walk and Kill.", "categories": [] } }

public class JokeDTO {
  private ValueDTO value;

  public ValueDTO getValue() {
    return value;
  }
}

public class ValueDTO {
  private String joke;

  public String getJoke() {
    return joke;
  }
}

> { "type": "success", "value": { "id": 31, "joke": "Chuck Norris has two speeds: Walk and Kill.", "categories": [] } }

@Service
public class JokeServiceRestImpl implements JokeService {

  ...
  
  @Override
  public String getJoke() {
    ResponseEntity<Joke> responseEntity =
      restTemplate.getForEntity(URL, Joke.class);
      
    return responseEntity.getBody().getValue().getJoke();
  }
}

> Chuck Norris crossed the road. No one has ever dared question his motives.

dependencies {
  // ...
  compile 
    group: 'org.springframework.shell',
    name: 'spring-shell-starter',
  // ...
}

@ShellComponent
public class ShellCommands {
  private final JokeService jokeService;
  private String lastJoke;

  @ShellMethod("Get joke about Chuck Norris.")
  public String joke() {
    lastJoke = jokeService.getJoke();
    return lastJoke;
  } 
}

shell:>joke
Chuck Norris hosting is 101% uptime guaranteed.
shell:>joke
Product Owners never ask Chuck Norris for more features.
They ask for mercy.

@RunWith(SpringRunner.class)
@SpringBootTest(
  classes = JokesApplication.class,
  properties = {
    InteractiveShellApplicationRunner
      .SPRING_SHELL_INTERACTIVE_ENABLED + "=false",
    ScriptShellApplicationRunner
      .SPRING_SHELL_SCRIPT_ENABLED + "=false"
  }
)
public class RestJokeRetrieverTest {
// ...

org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration,\

@Configuration
@ConditionalOnClass(ObjectMapper.class)
public class JacksonAutoConfiguration {
  @Bean
  public JsonComponentModule jsonComponentModule() {
    return new JsonComponentModule();
  }

java -jar jokes.jar --debug

============================
CONDITIONS EVALUATION REPORT
============================


Positive matches:
-----------------

 CodecsAutoConfiguration.JacksonCodecConfiguration matched:
   - @ConditionalOnClass found required class 
   'com.fasterxml.jackson.databind.ObjectMapper'
   (OnClassCondition)

@Override
public void save(String jokeText) {
  jdbcTemplate.update(
    "INSERT INTO jokes (joke) VALUES (?)"
    , jokeText);
}

@Override
public List<String> getAll() {
  return jdbcTemplate.query(
    "SELECT joke FROM jokes",
    (rs, rowNum) -> rs.getString("joke"));
}

# путь к файлу
spring.datasource.url=jdbc:h2:file:./data/jokes
spring.datasource.driverClassName=org.h2.Driver

# логин
spring.datasource.username=sa

# пароль
spring.datasource.password=sa

# веб консоль
spring.h2.console.enabled=true

// используйте метод exchange RestTemplate. 
// на входу ему нужна RequestEntity, которую можно создать
// указав в конструкторе HTTP заголовки, HTTP метод и URI

// Заголовки создайте так:
MultiValueMap<String, String> headers = new LinkedMultiValueMap<>();
headers.add(HEADER_NAME, HEADER_VALUE);

// URI
String url = "http://example.com";
URI.create(url);

@ShellMethod("Get joke about Chuck Norris.")
public String joke(
  @ShellOption(defaultValue = "NERDY") 
    String category) {
  lastJoke = jokeService.getJoke(category);
  return lastJoke;
}