Introduce spring-boot-autoconfigure-processor

Add an annotation processor that generates properties files for certain
auto-configuration class annotations. Currently attribute values from
@AutoConfigureOrder, @AutoConfigureBefore, @AutoConfigureAfter and
@ConditionalOnClass annotations are stored.

The properties file will allow optimizations to be added in the
`spring-boot-autoconfigure` project. Primarily by removing the need
to ASM parse as many `.class` files.

See spring-projectsgh-7573

eclipse/spring-boot-project.setup

@@ -143,7 +143,7 @@
         name="spring-boot-tools">
       <predicate
           xsi:type="predicates:NamePredicate"
-          pattern="spring-boot-(tools|antlib|configuration-.*|loader|.*-tools|.*-plugin)"/>
+          pattern="spring-boot-(tools|antlib|configuration-.*|loader|.*-tools|.*-plugin|autoconfigure-processor)"/>
     </workingSet>
     <workingSet
         name="spring-boot-starters">

spring-boot-actuator/pom.xml

@@ -274,6 +274,11 @@
 			<optional>true</optional>
 		</dependency>
 		<!-- Annotation processing -->
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-autoconfigure-processor</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-configuration-processor</artifactId>

spring-boot-autoconfigure/pom.xml

@@ -608,6 +608,11 @@
 			<optional>true</optional>
 		</dependency>
 		<!-- Annotation processing -->
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-autoconfigure-processor</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-configuration-processor</artifactId>

spring-boot-dependencies/pom.xml

@@ -271,6 +271,11 @@
 				<artifactId>spring-boot-autoconfigure</artifactId>
 				<version>1.5.0.BUILD-SNAPSHOT</version>
 			</dependency>
+			<dependency>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-autoconfigure-processor</artifactId>
+				<version>1.5.0.BUILD-SNAPSHOT</version>
+			</dependency>
 			<dependency>
 				<groupId>org.springframework.boot</groupId>
 				<artifactId>spring-boot-configuration-metadata</artifactId>

spring-boot-devtools/pom.xml

@@ -80,6 +80,11 @@
 			<optional>true</optional>
 		</dependency>
 		<!-- Annotation processing -->
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-autoconfigure-processor</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-configuration-processor</artifactId>

spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/TestCompiler.java → spring-boot-test-support/src/main/java/org/springframework/boot/junit/compiler/TestCompiler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.configurationprocessor;
+package org.springframework.boot.junit.compiler;
 
 import java.io.File;
 import java.io.IOException;
@@ -40,7 +40,10 @@
  */
 public class TestCompiler {
 
-	public static final File ORIGINAL_SOURCE_FOLDER = new File("src/test/java");
+	/**
+	 * The default source folder.
+	 */
+	public static final File SOURCE_FOLDER = new File("src/test/java");
 
 	private final JavaCompiler compiler;
 
@@ -100,7 +103,7 @@ public static String sourcePathFor(Class<?> type) {
 	}
 
 	protected File getSourceFolder() {
-		return ORIGINAL_SOURCE_FOLDER;
+		return SOURCE_FOLDER;
 	}
 
 	/**

spring-boot-test-support/src/main/java/org/springframework/boot/junit/compiler/package-info.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2012-2017 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.
+ */
+
+/**
+ * Utilities to work with the Java compiler at test time.
+ */
+package org.springframework.boot.junit.compiler;

spring-boot-tools/pom.xml

@@ -20,6 +20,7 @@
 		<main.basedir>${basedir}/..</main.basedir>
 	</properties>
 	<modules>
+		<module>spring-boot-autoconfigure-processor</module>
 		<module>spring-boot-configuration-metadata</module>
 		<module>spring-boot-configuration-processor</module>
 		<module>spring-boot-loader</module>

spring-boot-tools/spring-boot-autoconfigure-processor/pom.xml

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-tools</artifactId>
+		<version>1.5.0.BUILD-SNAPSHOT</version>
+	</parent>
+	<artifactId>spring-boot-autoconfigure-processor</artifactId>
+	<name>Spring Boot Auto-Configure Annotation Processor</name>
+	<description>Spring Auto-Configure Annotation Processor</description>
+	<url>http://projects.spring.io/spring-boot/</url>
+	<organization>
+		<name>Pivotal Software, Inc.</name>
+		<url>http://www.spring.io</url>
+	</organization>
+	<properties>
+		<main.basedir>${basedir}/../..</main.basedir>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-test-support</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<configuration>
+					<!-- Ensure own annotation processor doesn't kick in -->
+					<proc>none</proc>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+</project>

spring-boot-tools/spring-boot-autoconfigure-processor/src/main/java/org/springframework/boot/autoconfigureprocessor/AutoConfigureAnnotationProcessor.java

@@ -0,0 +1,214 @@
+/*
+ * Copyright 2012-2017 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.autoconfigureprocessor;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.Set;
+
+import javax.annotation.processing.AbstractProcessor;
+import javax.annotation.processing.RoundEnvironment;
+import javax.annotation.processing.SupportedAnnotationTypes;
+import javax.lang.model.element.AnnotationMirror;
+import javax.lang.model.element.AnnotationValue;
+import javax.lang.model.element.Element;
+import javax.lang.model.element.ElementKind;
+import javax.lang.model.element.ExecutableElement;
+import javax.lang.model.element.TypeElement;
+import javax.lang.model.type.DeclaredType;
+import javax.lang.model.type.TypeMirror;
+import javax.tools.FileObject;
+import javax.tools.StandardLocation;
+
+/**
+ * Annotation processor to store certain annotations from auto-configuration classes in a
+ * property file.
+ *
+ * @author Madhura Bhave
+ * @author Phillip Webb
+ */
+@SupportedAnnotationTypes({ "org.springframework.context.annotation.Configuration",
+		"org.springframework.boot.autoconfigure.condition.ConditionalOnClass",
+		"org.springframework.boot.autoconfigure.AutoConfigureBefore",
+		"org.springframework.boot.autoconfigure.AutoConfigureAfter",
+		"org.springframework.boot.autoconfigure.AutoConfigureOrder" })
+public class AutoConfigureAnnotationProcessor extends AbstractProcessor {
+
+	protected static final String PROPERTIES_PATH = "META-INF/"
+			+ "spring-autoconfigure-metadata.properties";
+
+	private Map<String, String> annotations;
+
+	private final Properties properties = new Properties();
+
+	public AutoConfigureAnnotationProcessor() {
+		Map<String, String> annotations = new LinkedHashMap<String, String>();
+		addAnnotations(annotations);
+		this.annotations = Collections.unmodifiableMap(annotations);
+	}
+
+	protected void addAnnotations(Map<String, String> annotations) {
+		annotations.put("Configuration",
+				"org.springframework.context.annotation.Configuration");
+		annotations.put("ConditionalOnClass",
+				"org.springframework.boot.autoconfigure.condition.ConditionalOnClass");
+		annotations.put("AutoConfigureBefore",
+				"org.springframework.boot.autoconfigure.AutoConfigureBefore");
+		annotations.put("AutoConfigureAfter",
+				"org.springframework.boot.autoconfigure.AutoConfigureAfter");
+		annotations.put("AutoConfigureOrder",
+				"org.springframework.boot.autoconfigure.AutoConfigureOrder");
+	}
+
+	@Override
+	public boolean process(Set<? extends TypeElement> annotations,
+			RoundEnvironment roundEnv) {
+		for (Map.Entry<String, String> entry : this.annotations.entrySet()) {
+			process(roundEnv, entry.getKey(), entry.getValue());
+		}
+		if (roundEnv.processingOver()) {
+			try {
+				writeProperties();
+			}
+			catch (Exception ex) {
+				throw new IllegalStateException("Failed to write metadata", ex);
+			}
+		}
+		return false;
+	}
+
+	private void process(RoundEnvironment roundEnv, String propertyKey,
+			String annotationName) {
+		TypeElement annotationType = this.processingEnv.getElementUtils()
+				.getTypeElement(annotationName);
+		if (annotationType != null) {
+			for (Element element : roundEnv.getElementsAnnotatedWith(annotationType)) {
+				Element enclosingElement = element.getEnclosingElement();
+				if (enclosingElement != null
+						&& enclosingElement.getKind() == ElementKind.PACKAGE) {
+					processElement(element, propertyKey, annotationName);
+				}
+			}
+		}
+	}
+
+	private void processElement(Element element, String propertyKey,
+			String annotationName) {
+		try {
+			String qualifiedName = getQualifiedName(element);
+			AnnotationMirror annotation = getAnnotation(element, annotationName);
+			if (qualifiedName != null && annotation != null) {
+				List<Object> values = getValues(annotation);
+				this.properties.put(qualifiedName + "." + propertyKey,
+						toCommaDelimitedString(values));
+				this.properties.put(qualifiedName, "");
+			}
+		}
+		catch (Exception ex) {
+			throw new IllegalStateException(
+					"Error processing configuration meta-data on " + element, ex);
+		}
+	}
+
+	private AnnotationMirror getAnnotation(Element element, String type) {
+		if (element != null) {
+			for (AnnotationMirror annotation : element.getAnnotationMirrors()) {
+				if (type.equals(annotation.getAnnotationType().toString())) {
+					return annotation;
+				}
+			}
+		}
+		return null;
+	}
+
+	private String toCommaDelimitedString(List<Object> list) {
+		StringBuilder result = new StringBuilder();
+		for (Object item : list) {
+			result.append(result.length() != 0 ? "," : "");
+			result.append(item);
+		}
+		return result.toString();
+	}
+
+	@SuppressWarnings("unchecked")
+	private List<Object> getValues(AnnotationMirror annotation) {
+		List<Object> result = new ArrayList<Object>();
+		for (Map.Entry<? extends ExecutableElement, ? extends AnnotationValue> entry : annotation
+				.getElementValues().entrySet()) {
+			String attributeName = entry.getKey().getSimpleName().toString();
+			if ("name".equals(attributeName) || "value".equals(attributeName)) {
+				Object value = entry.getValue().getValue();
+				if (value instanceof List) {
+					for (AnnotationValue annotationValue : (List<AnnotationValue>) value) {
+						result.add(annotationValue.getValue());
+					}
+				}
+				else {
+					result.add(value);
+				}
+			}
+		}
+		return result;
+	}
+
+	private String getQualifiedName(Element element) {
+		if (element != null) {
+			TypeElement enclosingElement = getEnclosingTypeElement(element.asType());
+			if (enclosingElement != null) {
+				return getQualifiedName(enclosingElement) + "$"
+						+ ((DeclaredType) element.asType()).asElement().getSimpleName()
+								.toString();
+			}
+			if (element instanceof TypeElement) {
+				return ((TypeElement) element).getQualifiedName().toString();
+			}
+		}
+		return null;
+	}
+
+	private TypeElement getEnclosingTypeElement(TypeMirror type) {
+		if (type instanceof DeclaredType) {
+			DeclaredType declaredType = (DeclaredType) type;
+			Element enclosingElement = declaredType.asElement().getEnclosingElement();
+			if (enclosingElement != null && enclosingElement instanceof TypeElement) {
+				return (TypeElement) enclosingElement;
+			}
+		}
+		return null;
+	}
+
+	private void writeProperties() throws IOException {
+		if (!this.properties.isEmpty()) {
+			FileObject file = this.processingEnv.getFiler()
+					.createResource(StandardLocation.CLASS_OUTPUT, "", PROPERTIES_PATH);
+			OutputStream outputStream = file.openOutputStream();
+			try {
+				this.properties.store(outputStream, null);
+			}
+			finally {
+				outputStream.close();
+			}
+		}
+	}
+
+}

spring-boot-tools/spring-boot-autoconfigure-processor/src/main/resources/META-INF/services/javax.annotation.processing.Processor

@@ -0,0 +1 @@
+org.springframework.boot.autoconfigureprocessor.AutoConfigureAnnotationProcessor