Process all non-private methods, not just public methods

Previously, the configuration processor would ignore any
@ConfigurationProperties-annotated methods that were not public. This
prevented metadata generation for package-private @Bean methods such
as those in DataSourceConfiguration's inner-classes for DBCP2, Hikari,
and Tomcat JDBC.

This commit updates the annotation processor so that it will process
any non-private method annotated with @ConfigurationProperties.

Fixes gh-18124

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

@@ -216,7 +216,8 @@ public class ConfigurationMetadataAnnotationProcessor extends AbstractProcessor
 	}
 
 	private void processExecutableElement(String prefix, ExecutableElement element) {
-		if (element.getModifiers().contains(Modifier.PUBLIC) && (TypeKind.VOID != element.getReturnType().getKind())) {
+		if ((!element.getModifiers().contains(Modifier.PRIVATE))
+				&& (TypeKind.VOID != element.getReturnType().getKind())) {
 			Element returns = this.processingEnv.getTypeUtils().asElement(element.getReturnType());
 			if (returns instanceof TypeElement) {
 				ItemMetadata group = ItemMetadata.newGroup(prefix,

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

@@ -24,7 +24,10 @@ import org.springframework.boot.configurationsample.method.DeprecatedMethodConfi
 import org.springframework.boot.configurationsample.method.EmptyTypeMethodConfig;
 import org.springframework.boot.configurationsample.method.InvalidMethodConfig;
 import org.springframework.boot.configurationsample.method.MethodAndClassConfig;
-import org.springframework.boot.configurationsample.method.SimpleMethodConfig;
+import org.springframework.boot.configurationsample.method.PackagePrivateMethodConfig;
+import org.springframework.boot.configurationsample.method.PrivateMethodConfig;
+import org.springframework.boot.configurationsample.method.ProtectedMethodConfig;
+import org.springframework.boot.configurationsample.method.PublicMethodConfig;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -36,13 +39,32 @@ import static org.assertj.core.api.Assertions.assertThat;
 class MethodBasedMetadataGenerationTests extends AbstractMetadataGenerationTests {
 
 	@Test
-	void simpleMethodConfig() {
-		ConfigurationMetadata metadata = compile(SimpleMethodConfig.class);
-		assertThat(metadata).has(Metadata.withGroup("foo").fromSource(SimpleMethodConfig.class));
+	void publicMethodConfig() {
+		methodConfig(PublicMethodConfig.class, PublicMethodConfig.Foo.class);
+	}
+
+	@Test
+	void protectedMethodConfig() {
+		methodConfig(ProtectedMethodConfig.class, ProtectedMethodConfig.Foo.class);
+	}
+
+	@Test
+	void packagePrivateMethodConfig() {
+		methodConfig(PackagePrivateMethodConfig.class, PackagePrivateMethodConfig.Foo.class);
+	}
+
+	private void methodConfig(Class<?> config, Class<?> properties) {
+		ConfigurationMetadata metadata = compile(config);
+		assertThat(metadata).has(Metadata.withGroup("foo").fromSource(config));
+		assertThat(metadata).has(Metadata.withProperty("foo.name", String.class).fromSource(properties));
 		assertThat(metadata)
-				.has(Metadata.withProperty("foo.name", String.class).fromSource(SimpleMethodConfig.Foo.class));
-		assertThat(metadata).has(Metadata.withProperty("foo.flag", Boolean.class).withDefaultValue(false)
-				.fromSource(SimpleMethodConfig.Foo.class));
+				.has(Metadata.withProperty("foo.flag", Boolean.class).withDefaultValue(false).fromSource(properties));
+	}
+
+	@Test
+	void privateMethodConfig() {
+		ConfigurationMetadata metadata = compile(PrivateMethodConfig.class);
+		assertThat(metadata).doesNotHave(Metadata.withGroup("foo"));
 	}
 
 	@Test

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

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2012-2019 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.configurationsample.method;
+
+import org.springframework.boot.configurationsample.ConfigurationProperties;
+
+/**
+ * Sample for testing package-private method configuration.
+ *
+ * @author Andy Wilkinson
+ */
+public class PackagePrivateMethodConfig {
+
+	@ConfigurationProperties(prefix = "foo")
+	Foo foo() {
+		return new Foo();
+	}
+
+	public static class Foo {
+
+		private String name;
+
+		private boolean flag;
+
+		public String getName() {
+			return this.name;
+		}
+
+		public void setName(String name) {
+			this.name = name;
+		}
+
+		public boolean isFlag() {
+			return this.flag;
+		}
+
+		public void setFlag(boolean flag) {
+			this.flag = flag;
+		}
+
+	}
+
+}

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

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2012-2019 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.configurationsample.method;
+
+import org.springframework.boot.configurationsample.ConfigurationProperties;
+
+/**
+ * Sample for testing private method configuration.
+ *
+ * @author Andy Wilkinson
+ */
+public class PrivateMethodConfig {
+
+	@ConfigurationProperties(prefix = "foo")
+	private Foo foo() {
+		return new Foo();
+	}
+
+	public static class Foo {
+
+		private String name;
+
+		private boolean flag;
+
+		public String getName() {
+			return this.name;
+		}
+
+		public void setName(String name) {
+			this.name = name;
+		}
+
+		public boolean isFlag() {
+			return this.flag;
+		}
+
+		public void setFlag(boolean flag) {
+			this.flag = flag;
+		}
+
+	}
+
+}

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

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2012-2019 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.configurationsample.method;
+
+import org.springframework.boot.configurationsample.ConfigurationProperties;
+
+/**
+ * Sample for testing protected method configuration.
+ *
+ * @author Andy Wilkinson
+ */
+public class ProtectedMethodConfig {
+
+	@ConfigurationProperties(prefix = "foo")
+	protected Foo foo() {
+		return new Foo();
+	}
+
+	public static class Foo {
+
+		private String name;
+
+		private boolean flag;
+
+		public String getName() {
+			return this.name;
+		}
+
+		public void setName(String name) {
+			this.name = name;
+		}
+
+		public boolean isFlag() {
+			return this.flag;
+		}
+
+		public void setFlag(boolean flag) {
+			this.flag = flag;
+		}
+
+	}
+
+}

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

@@ -19,11 +19,11 @@ package org.springframework.boot.configurationsample.method;
 import org.springframework.boot.configurationsample.ConfigurationProperties;
 
 /**
- * Sample for testing simple method configuration.
+ * Sample for testing public method configuration.
  *
  * @author Stephane Nicoll
  */
-public class SimpleMethodConfig {
+public class PublicMethodConfig {
 
 	@ConfigurationProperties(prefix = "foo")
 	public Foo foo() {