Add Kotlin alternatives to Java documentation samples

See gh-29499

Author: p7nov

spring-boot-project/spring-boot-docs/build.gradle

@@ -4,6 +4,7 @@ plugins {
 	id "org.asciidoctor.jvm.convert"
 	id "org.springframework.boot.conventions"
 	id "org.springframework.boot.deployed"
+	id 'org.jetbrains.kotlin.jvm'
 }
 
 description = "Spring Boot Docs"
@@ -102,6 +103,7 @@ dependencies {
 		exclude group: "javax.xml.bind", module: "jaxb-api"
 		exclude group: "org.jboss.spec.javax.transaction", module: "jboss-transaction-api_1.2_spec"
 	}
+	implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
 	implementation("org.jooq:jooq") {
 		exclude group: "javax.xml.bind", module: "jaxb-api"
 	}
@@ -321,6 +323,9 @@ syncDocumentationSourceForAsciidoctor {
 	from("src/test/java") {
 		into "test/java"
 	}
+	from("src/main/kotlin") {
+		into "main/kotlin"
+	}
 	from("src/main/groovy") {
 		into "main/groovy"
 	}
@@ -345,6 +350,9 @@ syncDocumentationSourceForAsciidoctorMultipage {
 	from("src/test/java") {
 		into "test/java"
 	}
+	from("src/main/kotlin") {
+		into "main/kotlin"
+	}
 	from("src/main/groovy") {
 		into "main/groovy"
 	}
@@ -369,6 +377,9 @@ syncDocumentationSourceForAsciidoctorPdf {
 	from("src/test/java") {
 		into "test/java"
 	}
+	from("src/main/kotlin") {
+		into "main/kotlin"
+	}
 	from("src/main/groovy") {
 		into "main/groovy"
 	}

spring-boot-project/spring-boot-docs/src/docs/asciidoc/attributes.adoc

@@ -19,6 +19,7 @@
 :github-issues: https://github.com/{github-repo}/issues/
 :github-wiki: https://github.com/{github-repo}/wiki
 :docs-java: {docdir}/../main/java/org/springframework/boot/docs
+:docs-kotlin: {docdir}/../main/kotlin/org/springframework/boot/docs
 :docs-groovy: {docdir}/../main/groovy/org/springframework/boot/docs
 :docs-resources: ../../main/resources
 :spring-boot-code: https://github.com/{github-repo}/tree/{github-tag}

spring-boot-project/spring-boot-docs/src/main/kotlin/org/springframework/boot/docs/actuator/cloudfoundry/customcontextpath/MyCloudFoundryConfiguration.kt

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2012-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.actuator.cloudfoundry.customcontextpath
+
+import org.apache.catalina.Host
+import org.apache.catalina.core.StandardContext
+import org.apache.catalina.startup.Tomcat.FixContextListener
+import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory
+import org.springframework.boot.web.servlet.ServletContextInitializer
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+import java.io.IOException
+import javax.servlet.*
+import kotlin.jvm.Throws
+
+@Configuration(proxyBeanMethods = false)
+class MyCloudFoundryConfiguration {
+	@Bean
+	fun servletWebServerFactory(): TomcatServletWebServerFactory {
+		return object : TomcatServletWebServerFactory() {
+			override fun prepareContext(host: Host, initializers: Array<ServletContextInitializer>) {
+				super.prepareContext(host, initializers)
+				val child = StandardContext()
+				child.addLifecycleListener(FixContextListener())
+				child.path = "/cloudfoundryapplication"
+				val initializer = getServletContextInitializer(contextPath)
+				child.addServletContainerInitializer(initializer, emptySet())
+				child.crossContext = true
+				host.addChild(child)
+			}
+		}
+	}
+
+	private fun getServletContextInitializer(contextPath: String): ServletContainerInitializer {
+		return ServletContainerInitializer { classes: Set<Class<*>?>?, context: ServletContext ->
+			val servlet: Servlet = object : GenericServlet() {
+				@Throws(ServletException::class, IOException::class)
+				override fun service(req: ServletRequest, res: ServletResponse) {
+					val context = req.servletContext.getContext(contextPath)
+					context.getRequestDispatcher("/cloudfoundryapplication").forward(req, res)
+				}
+			}
+			context.addServlet("cloudfoundry", servlet).addMapping("/*")
+		}
+	}
+}

spring-boot-project/spring-boot-docs/src/main/kotlin/org/springframework/boot/docs/actuator/endpoints/health/reactivehealthindicators/MyReactiveHealthIndicator.kt

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2012-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.actuator.endpoints.health.reactivehealthindicators
+
+import org.springframework.boot.actuate.health.Health
+import org.springframework.boot.actuate.health.ReactiveHealthIndicator
+import org.springframework.stereotype.Component
+import reactor.core.publisher.Mono
+
+@Component
+class MyReactiveHealthIndicator : ReactiveHealthIndicator {
+	override fun health(): Mono<Health> {
+		// @formatter:off
+		return doHealthCheck()!!.onErrorResume { exception: Throwable? ->
+			Mono.just(
+				Health.Builder().down(exception).build()
+			)
+		}
+		// @formatter:on
+	}
+
+	private fun doHealthCheck(): Mono<Health>? {
+		// perform some specific health check
+		return  /**/null
+	}
+}

spring-boot-project/spring-boot-docs/src/main/kotlin/org/springframework/boot/docs/actuator/endpoints/health/writingcustomhealthindicators/MyHealthIndicator.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2012-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.actuator.endpoints.health.writingcustomhealthindicators
+
+import org.springframework.boot.actuate.health.Health
+import org.springframework.boot.actuate.health.HealthIndicator
+import org.springframework.stereotype.Component
+
+@Component
+class MyHealthIndicator : HealthIndicator {
+	override fun health(): Health {
+		val errorCode = check()
+		return if (errorCode != 0) {
+			Health.down().withDetail("Error Code", errorCode).build()
+		} else Health.up().build()
+	}
+
+	private fun check(): Int {
+		// perform some specific health check
+		return  /**/0
+	}
+}

spring-boot-project/spring-boot-docs/src/main/kotlin/org/springframework/boot/docs/actuator/endpoints/implementingcustom/CustomData.kt

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2012-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.actuator.endpoints.implementingcustom
+
+class CustomData(val name: String, val counter: Int)

spring-boot-project/spring-boot-docs/src/main/kotlin/org/springframework/boot/docs/actuator/endpoints/implementingcustom/MyEndpoint.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2012-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.actuator.endpoints.implementingcustom
+
+import org.springframework.boot.actuate.endpoint.annotation.Endpoint
+import org.springframework.boot.actuate.endpoint.annotation.ReadOperation
+import org.springframework.boot.actuate.endpoint.annotation.WriteOperation
+
+@Endpoint(id = "custom")
+class MyEndpoint {
+	// tag::read[]
+	@get:ReadOperation
+	val data: CustomData
+		get() = CustomData("test", 5)
+
+	// end::read[]
+	// tag::write[]
+	@WriteOperation
+	fun updateData(name: String?, counter: Int) {
+		// injects "test" and 42
+	} // end::write[]
+}

spring-boot-project/spring-boot-docs/src/main/kotlin/org/springframework/boot/docs/actuator/endpoints/info/writingcustominfocontributors/MyInfoContributor.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2012-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.actuator.endpoints.info.writingcustominfocontributors
+
+import org.springframework.boot.actuate.info.Info
+import org.springframework.boot.actuate.info.InfoContributor
+import org.springframework.stereotype.Component
+import java.util.*
+
+@Component
+class MyInfoContributor : InfoContributor {
+	override fun contribute(builder: Info.Builder) {
+		builder.withDetail("example", Collections.singletonMap("key", "value"))
+	}
+}

spring-boot-project/spring-boot-docs/src/main/kotlin/org/springframework/boot/docs/actuator/endpoints/security/exposeall/MySecurityConfiguration.kt

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2012-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.actuator.endpoints.security.exposeall
+
+import org.springframework.boot.actuate.autoconfigure.security.servlet.EndpointRequest
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+import org.springframework.security.config.annotation.web.builders.HttpSecurity
+import org.springframework.security.config.annotation.web.configurers.ExpressionUrlAuthorizationConfigurer
+import org.springframework.security.config.annotation.web.configurers.ExpressionUrlAuthorizationConfigurer.ExpressionInterceptUrlRegistry
+import org.springframework.security.web.SecurityFilterChain
+
+@Configuration(proxyBeanMethods = false)
+class MySecurityConfiguration {
+	@Bean
+	fun securityFilterChain(http: HttpSecurity): SecurityFilterChain {
+		http.requestMatcher(EndpointRequest.toAnyEndpoint())
+			.authorizeRequests { requests: ExpressionUrlAuthorizationConfigurer<HttpSecurity>.ExpressionInterceptUrlRegistry ->
+				requests.anyRequest().permitAll()
+			}
+		return http.build()
+	}
+}

spring-boot-project/spring-boot-docs/src/main/kotlin/org/springframework/boot/docs/actuator/endpoints/security/typical/MySecurityConfiguration.kt

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2012-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.actuator.endpoints.security.typical
+
+import org.springframework.boot.actuate.autoconfigure.security.servlet.EndpointRequest
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+import org.springframework.security.config.annotation.web.builders.HttpSecurity
+import org.springframework.security.config.annotation.web.configurers.ExpressionUrlAuthorizationConfigurer
+import org.springframework.security.config.annotation.web.configurers.ExpressionUrlAuthorizationConfigurer.ExpressionInterceptUrlRegistry
+import org.springframework.security.web.SecurityFilterChain
+
+@Configuration(proxyBeanMethods = false)
+class MySecurityConfiguration {
+	@Bean
+	fun securityFilterChain(http: HttpSecurity): SecurityFilterChain {
+		http.requestMatcher(EndpointRequest.toAnyEndpoint())
+			.authorizeRequests { requests: ExpressionUrlAuthorizationConfigurer<HttpSecurity>.ExpressionInterceptUrlRegistry ->
+				requests.anyRequest().hasRole("ENDPOINT_ADMIN")
+			}
+		http.httpBasic()
+		return http.build()
+	}
+}