spring boot与ktor整合的实现方法

dependencies {
  implementation "org.springframework.boot:spring-boot-starter-aop:${springBootVersion}"
  implementation "io.ktor:ktor-jackson:${ktorVersion}"
  compile "io.ktor:ktor-server-netty:${ktorVersion}"
  compile "io.ktor:ktor-html-builder:${ktorVersion}"

  testImplementation "org.springframework.boot:spring-boot-starter-test:${springBootVersion}"
  testCompile "io.ktor:ktor-client-apache:${ktorVersion}"
  testCompile "io.ktor:ktor-server-test-host:${ktorVersion}"
}

jar {
  from {
    configurations.runtime.collect { zipTree(it) }
  }
}

task sourceJar(type: Jar) {
  from sourceSets.main.allSource
  classifier 'sources'
}

interface KRouter {
  fun Routing.route()
}

@ContextDsl
fun Routing.request(
 path: String, 
 body: PipelineInterceptor<Unit, ApplicationCall>
) = route(path) { handle(body) }

interface KModule {

  fun Application.defaultRegister(
   useCompress: Boolean = false, 
   redirectHttps: Boolean = false, 
   headers: String = ""
  ) {
    install(ContentNegotiation) { jackson { } }
    install(PartialContent) { maxRangeCount = 10 }
    if (useCompress) {
      install(Compression) {
        gzip { priority = 1.0 }
        deflate {
          priority = 10.0
          minimumSize(1024)
        }
      }
    }
    if (redirectHttps) {
      install(HttpsRedirect) {
        sslPort = URLProtocol.HTTPS.defaultPort
        permanentRedirect = true
      }
    }
    if (headers != "") {
      install(DefaultHeaders) {
        headers.toCookieMap().forEach { (t, u) -> header(t, "$u") }
      }
    }
  }

  @ContextDsl
  fun Application.register()
}

/**
 * spring.ktor 配置项
 * @param host 服务器主机名
 * @param port 绑定端口
 * @param compress 是否启用压缩
 * @param redirectHttps 是否自动重定向到 https
 * @param headers 默认的请求头
 */
@ConfigurationProperties(prefix = "spring.ktor")
open class KProperties(
    open var host: String = "0.0.0.0",
    open var port: Int = 8080,
    open var compress: Boolean = false,
    open var redirectHttps: Boolean = false,
    open var headers: String = ""
)

@Configuration
@EnableConfigurationProperties(KProperties::class)
open class KConfiguration {

  @Resource
  private lateinit var properties: KProperties

  @Bean
  @ConditionalOnMissingBean
  open fun engineFactory() = Netty

  @Bean
  @ConditionalOnMissingBean
  open fun applicationEngine(
   engineFactory: ApplicationEngineFactory<ApplicationEngine, out ApplicationEngine.Configuration>, 
   context: ApplicationContext
  ): ApplicationEngine {
    return embeddedServer(engineFactory, host = properties.host, port = properties.port) {
      val modules = context.getBeansOfType(KModule::class.java).values
      val routes = context.getBeansOfType(KRouter::class.java).values
      modules.forEach { it.apply {
        defaultRegister(
          useCompress = properties.compress, 
          redirectHttps = properties.redirectHttps, 
          headers = properties.headers)
        register()
      } }
      routing { routes.forEach { it.apply { route() } } }
    }.start()
  }

  @Bean
  @ConditionalOnMissingBean
  open fun application(
    applicationEngine: ApplicationEngine, 
    context: ApplicationContext
  ): Application = applicationEngine.environment.application
}

{
 "properties": [
  {
   "name": "spring.ktor.port",
   "type": "java.lang.Integer",
   "description": "服务启动时使用的端口号."
  },
  {
   "name": "spring.ktor.host",
   "type": "java.lang.String",
   "description": "服务的主机IP或域名."
  },
  {
   "name": "spring.ktor.compress",
   "type": "java.lang.Boolean",
   "description": "是否启用压缩."
  },
  {
   "name": "spring.ktor.redirectHttps",
   "type": "java.lang.Boolean",
   "description": "是否自动重定向到 https."
  },
  {
   "name": "spring.ktor.headers",
   "type": "java.lang.String",
   "description": "默认的请求头，以分号隔开."
  }
 ]
}

implementation "com.rarnu:spring-boot-starter-ktor:0.0.1"

spring:
 ktor:
  port: 9000
  compress: true
  headers: X-Engine=Ktor

class TestConfiguration {
  @Bean
  fun engineFactory() = TestEngine
}

@Component
class TestModule : KModule {
  override fun Application.register() {
  // TODO: install custom plugins
  }
}

@Controller
class TestController : KRouter {

  override fun Routing.route() {

    request("/") {
      call.respond(mapOf("code" to "001", "msg" to "操作成功。"))
    }

    get("/hello") {
      call.respondText { "OK" }
    }
  }
}

@SpringBootApplication
open class SpringKtorApplication

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

$ gradle clean build
$ java -jar test-ktor.jar