Only generate time-to-live property for matching endpoints

This commit makes sure that a "cache.time-to-live" property is not
generated for endpoints that do not have a main read operation (i.e. a
read operation with no parameter or only nullable parameters).

This matches the endpoint feature that provides caching for only such
operation.

Closes gh-11703

spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -1241,11 +1241,9 @@ content into your application. Rather, pick only the properties that you need.
 	management.endpoint.scheduledtasks.enabled= # Whether to enable the scheduled tasks endpoint.
 
 	# SESSIONS ENDPOINT ({sc-spring-boot-actuator}/session/SessionsEndpoint.{sc-ext}[SessionsEndpoint])
-	management.endpoint.sessions.cache.time-to-live=0ms # Maximum time that a response can be cached.
 	management.endpoint.sessions.enabled= # Whether to enable the sessions endpoint.
 
 	# SHUTDOWN ENDPOINT ({sc-spring-boot-actuator}/context/ShutdownEndpoint.{sc-ext}[ShutdownEndpoint])
-	management.endpoint.shutdown.cache.time-to-live=0ms # Maximum time that a response can be cached.
 	management.endpoint.shutdown.enabled=false # Whether to enable the shutdown endpoint.
 
 	# THREAD DUMP ENDPOINT ({sc-spring-boot-actuator}/management/ThreadDumpEndpoint.{sc-ext}[ThreadDumpEndpoint])

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/ConfigurationMetadataAnnotationProcessor.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -46,6 +46,7 @@ import javax.lang.model.element.VariableElement;
 import javax.lang.model.type.DeclaredType;
 import javax.lang.model.type.TypeKind;
 import javax.lang.model.type.TypeMirror;
+import javax.lang.model.util.ElementFilter;
 import javax.lang.model.util.Elements;
 import javax.tools.Diagnostic.Kind;
 
@@ -83,6 +84,11 @@ public class ConfigurationMetadataAnnotationProcessor extends AbstractProcessor
 	static final String ENDPOINT_ANNOTATION = "org.springframework.boot.actuate."
 			+ "endpoint.annotation.Endpoint";
 
+	static final String READ_OPERATION_ANNOTATION = "org.springframework.boot.actuate."
+			+ "endpoint.annotation.ReadOperation";
+
+	static final String NULLABLE_ANNOTATION = "org.springframework.lang.Nullable";
+
 	static final String LOMBOK_DATA_ANNOTATION = "lombok.Data";
 
 	static final String LOMBOK_GETTER_ANNOTATION = "lombok.Getter";
@@ -118,6 +124,10 @@ public class ConfigurationMetadataAnnotationProcessor extends AbstractProcessor
 		return ENDPOINT_ANNOTATION;
 	}
 
+	protected String readOperationAnnotation() {
+		return READ_OPERATION_ANNOTATION;
+	}
+
 	@Override
 	public SourceVersion getSupportedSourceVersion() {
 		return SourceVersion.latestSupported();
@@ -425,9 +435,32 @@ public class ConfigurationMetadataAnnotationProcessor extends AbstractProcessor
 				Boolean.class.getName(), type, null,
 				String.format("Whether to enable the %s endpoint.", endpointId),
 				(enabledByDefault == null ? true : enabledByDefault), null));
-		this.metadataCollector.add(ItemMetadata.newProperty(endpointKey,
-				"cache.time-to-live", Duration.class.getName(), type, null,
-				"Maximum time that a response can be cached.", 0, null));
+		if (hasMainReadOperation(element)) {
+			this.metadataCollector.add(ItemMetadata.newProperty(endpointKey,
+					"cache.time-to-live", Duration.class.getName(), type, null,
+					"Maximum time that a response can be cached.", 0, null));
+		}
+	}
+
+	private boolean hasMainReadOperation(TypeElement element) {
+		for (ExecutableElement method : ElementFilter
+				.methodsIn(element.getEnclosedElements())) {
+			if (hasAnnotation(method, readOperationAnnotation())
+					&& (TypeKind.VOID != method.getReturnType().getKind())
+					&& hasNoOrOptionalParameters(method)) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+	private boolean hasNoOrOptionalParameters(ExecutableElement method) {
+		for (VariableElement parameter : method.getParameters()) {
+			if (!hasAnnotation(parameter, NULLABLE_ANNOTATION)) {
+				return false;
+			}
+		}
+		return true;
 	}
 
 	private boolean isNested(Element returnType, VariableElement field,

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/ConfigurationMetadataAnnotationProcessorTests.java

@@ -591,8 +591,7 @@ public class ConfigurationMetadataAnnotationProcessorTests {
 		assertThat(metadata).has(Metadata.withGroup("management.endpoint.disabled")
 				.fromSource(DisabledEndpoint.class));
 		assertThat(metadata).has(enabledFlag("disabled", false));
-		assertThat(metadata).has(cacheTtl("disabled"));
-		assertThat(metadata.getItems()).hasSize(3);
+		assertThat(metadata.getItems()).hasSize(2);
 	}
 
 	@Test
@@ -601,8 +600,7 @@ public class ConfigurationMetadataAnnotationProcessorTests {
 		assertThat(metadata).has(Metadata.withGroup("management.endpoint.enabled")
 				.fromSource(EnabledEndpoint.class));
 		assertThat(metadata).has(enabledFlag("enabled", true));
-		assertThat(metadata).has(cacheTtl("enabled"));
-		assertThat(metadata.getItems()).hasSize(3);
+		assertThat(metadata.getItems()).hasSize(2);
 	}
 
 	@Test
@@ -634,8 +632,7 @@ public class ConfigurationMetadataAnnotationProcessorTests {
 		assertThat(metadata).has(Metadata.withGroup("management.endpoint.pascal-case")
 				.fromSource(CamelCaseEndpoint.class));
 		assertThat(metadata).has(enabledFlag("PascalCase", "pascal-case", true));
-		assertThat(metadata).has(cacheTtl("pascal-case"));
-		assertThat(metadata.getItems()).hasSize(3);
+		assertThat(metadata.getItems()).hasSize(2);
 	}
 
 	@Test
@@ -658,6 +655,25 @@ public class ConfigurationMetadataAnnotationProcessorTests {
 		assertThat(metadata.getItems()).hasSize(3);
 	}
 
+	@Test
+	public void incrementalEndpointBuildChangeCacheFlag() throws Exception {
+		TestProject project = new TestProject(this.temporaryFolder,
+				IncrementalEndpoint.class);
+		ConfigurationMetadata metadata = project.fullBuild();
+		assertThat(metadata).has(Metadata.withGroup("management.endpoint.incremental")
+				.fromSource(IncrementalEndpoint.class));
+		assertThat(metadata).has(enabledFlag("incremental", true));
+		assertThat(metadata).has(cacheTtl("incremental"));
+		assertThat(metadata.getItems()).hasSize(3);
+		project.replaceText(IncrementalEndpoint.class, "@Nullable String param",
+				"String param");
+		metadata = project.incrementalBuild(IncrementalEndpoint.class);
+		assertThat(metadata).has(Metadata.withGroup("management.endpoint.incremental")
+				.fromSource(IncrementalEndpoint.class));
+		assertThat(metadata).has(enabledFlag("incremental", true));
+		assertThat(metadata.getItems()).hasSize(2);
+	}
+
 	@Test
 	public void incrementalEndpointBuildEnableSpecificEndpoint() throws Exception {
 		TestProject project = new TestProject(this.temporaryFolder,

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/TestConfigurationMetadataAnnotationProcessor.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -48,6 +48,8 @@ public class TestConfigurationMetadataAnnotationProcessor
 
 	static final String ENDPOINT_ANNOTATION = "org.springframework.boot.configurationsample.Endpoint";
 
+	static final String READ_OPERATION_ANNOTATION = "org.springframework.boot.configurationsample.ReadOperation";
+
 	private ConfigurationMetadata metadata;
 
 	private final File outputLocation;
@@ -76,6 +78,11 @@ public class TestConfigurationMetadataAnnotationProcessor
 		return ENDPOINT_ANNOTATION;
 	}
 
+	@Override
+	protected String readOperationAnnotation() {
+		return READ_OPERATION_ANNOTATION;
+	}
+
 	@Override
 	protected ConfigurationMetadata writeMetaData() throws Exception {
 		super.writeMetaData();

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/ReadOperation.java

+/*
+ * Copyright 2012-2018 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
+ *
+ *      http://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.configurationsample;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Alternative to Spring Boot's {@code @ReadOperation} for testing (removes the need for a
+ * dependency on the real annotation).
+ *
+ * @author Stephane Nicoll
+ */
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+public @interface ReadOperation {
+
+	String[] produces() default {};
+
+}

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/endpoint/CustomPropertiesEndpoint.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -18,6 +18,7 @@ package org.springframework.boot.configurationsample.endpoint;
 
 import org.springframework.boot.configurationsample.ConfigurationProperties;
 import org.springframework.boot.configurationsample.Endpoint;
+import org.springframework.boot.configurationsample.ReadOperation;
 
 /**
  * An endpoint with additional custom properties.
@@ -30,6 +31,7 @@ public class CustomPropertiesEndpoint {
 
 	private String name = "test";
 
+	@ReadOperation
 	public String getName() {
 		return this.name;
 	}

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/endpoint/EnabledEndpoint.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -17,6 +17,7 @@
 package org.springframework.boot.configurationsample.endpoint;
 
 import org.springframework.boot.configurationsample.Endpoint;
+import org.springframework.boot.configurationsample.ReadOperation;
 
 /**
  * An endpoint that is enabled unless configured explicitly.
@@ -26,4 +27,13 @@ import org.springframework.boot.configurationsample.Endpoint;
 @Endpoint(id = "enabled")
 public class EnabledEndpoint {
 
+	public String someMethod() {
+		return "not a read operation";
+	}
+
+	@ReadOperation
+	public String retrieve(String parameter, Integer anotherParameter)  {
+		return "not a main read operation";
+	}
+
 }

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/endpoint/SimpleEndpoint.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -17,6 +17,7 @@
 package org.springframework.boot.configurationsample.endpoint;
 
 import org.springframework.boot.configurationsample.Endpoint;
+import org.springframework.boot.configurationsample.ReadOperation;
 
 /**
  * A simple endpoint with no default override.
@@ -26,4 +27,9 @@ import org.springframework.boot.configurationsample.Endpoint;
 @Endpoint(id = "simple")
 public class SimpleEndpoint {
 
+	@ReadOperation
+	public String invoke() {
+		return "test";
+	}
+
 }

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/endpoint/SpecificEndpoint.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -17,14 +17,21 @@
 package org.springframework.boot.configurationsample.endpoint;
 
 import org.springframework.boot.configurationsample.MetaEndpoint;
+import org.springframework.boot.configurationsample.ReadOperation;
+import org.springframework.lang.Nullable;
 
 /**
  * An meta-annotated endpoint similar to {@code @WebEndpoint} or {@code @JmxEndpoint} in
- * Boot.
+ * Spring Boot. Also with a package private read operation that has an optional argument.
  *
  * @author Stephane Nicoll
  */
 @MetaEndpoint(id = "specific", enableByDefault = true)
 public class SpecificEndpoint {
 
+	@ReadOperation
+	String invoke(@Nullable String param) {
+		return "test";
+	}
+
 }

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/endpoint/incremental/IncrementalEndpoint.java

@@ -17,6 +17,8 @@
 package org.springframework.boot.configurationsample.endpoint.incremental;
 
 import org.springframework.boot.configurationsample.Endpoint;
+import org.springframework.boot.configurationsample.ReadOperation;
+import org.springframework.lang.Nullable;
 
 /**
  * An endpoint that is enabled by default.
@@ -26,4 +28,9 @@ import org.springframework.boot.configurationsample.Endpoint;
 @Endpoint(id = "incremental")
 public class IncrementalEndpoint {
 
+	@ReadOperation
+	public String invoke(@Nullable String param) {
+		return "test";
+	}
+
 }

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/endpoint/incremental/IncrementalSpecificEndpoint.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -20,7 +20,7 @@ import org.springframework.boot.configurationsample.MetaEndpoint;
 
 /**
  * An meta-annotated endpoint similar to {@code @WebEndpoint} or {@code @JmxEndpoint} in
- * Boot.
+ * Spring Boot.
  *
  * @author Stephane Nicoll
  */