Generate standard configuration meta-data

Update the `spring-boot`, `spring-boot-autoconfigure` and
`spring-boot-actuator` project to generate configuration meta-data
files during compilation.

See gh-1001

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/DataSourceConfigMetadata.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2012-2014 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.autoconfigure.jdbc;
+
+import com.zaxxer.hikari.HikariDataSource;
+import org.apache.commons.dbcp.BasicDataSource;
+import org.apache.tomcat.jdbc.pool.DataSource;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+/**
+ * Expose the metadata of the supported data sources. Only used to harvest
+ * the relevant properties metadata.
+ *
+ * @author Stephane Nicoll
+ * @since 1.2.0
+ */
+class DataSourceConfigMetadata {
+
+	@ConfigurationProperties(DataSourceProperties.PREFIX)
+	public DataSource tomcatDataSource() {
+		return (DataSource) DataSourceBuilder.create().type(DataSource.class).build();
+	}
+
+	@ConfigurationProperties(DataSourceProperties.PREFIX)
+	public HikariDataSource hikariDataSource() {
+		return (HikariDataSource) DataSourceBuilder.create().type(HikariDataSource.class).build();
+	}
+
+	@ConfigurationProperties(DataSourceProperties.PREFIX)
+	public BasicDataSource dbcpDataSource() {
+		return (BasicDataSource)DataSourceBuilder.create().type(BasicDataSource.class).build();
+	}
+
+}

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/DataSourceProperties.java

@@ -80,7 +80,7 @@ public class DataSourceProperties implements BeanClassLoaderAware, InitializingB
 				.get(this.classLoader);
 	}
 
-	protected String getDriverClassName() {
+	public String getDriverClassName() {
 		if (StringUtils.hasText(this.driverClassName)) {
 			Assert.state(ClassUtils.isPresent(this.driverClassName, null),
 					"Cannot load driver class: " + this.driverClassName);

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/ServerProperties.java

@@ -381,4 +381,5 @@ public class ServerProperties implements EmbeddedServletContainerCustomizer {
 		}
 
 	}
+
 }

spring-boot-autoconfigure/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -0,0 +1,85 @@
+{"properties": [
+  {
+    "name": "spring.aop.auto",
+    "dataType": "java.lang.Boolean",
+    "description": "Automatically adds @EnableAspectJAutoProxy.",
+    "defaultValue": true,
+  },
+  {
+    "name": "spring.aop.proxy-target-class",
+    "dataType": "java.lang.Boolean",
+    "description": "Whether subclass-based (CGLIB) proxies are to be created (true) as opposed to standard Java interface-based proxies (false).",
+    "defaultValue": false,
+  },
+  {
+    "name": "spring.batch.enabled",
+    "dataType": "java.lang.Boolean",
+    "description": "Execute all Spring Batch jobs in the context on startup.",
+    "defaultValue": true,
+  },
+  {
+    "name": "spring.data.elasticsearch.repositories.enabled",
+    "dataType": "java.lang.Boolean",
+    "description": "Automatically enable Elasticsearch repositories.",
+    "defaultValue": true,
+  },
+  {
+    "name": "spring.data.jpa.repositories.enabled",
+    "dataType": "java.lang.Boolean",
+    "description": "Automatically enable JPA repositories.",
+    "defaultValue": true,
+  },
+  {
+    "name": "spring.data.mongo.repositories.enabled",
+    "dataType": "java.lang.Boolean",
+    "description": "Automatically enable Mongo repositories.",
+    "defaultValue": true,
+  },
+  {
+    "name": "spring.data.solr.repositories.enabled",
+    "dataType": "java.lang.Boolean",
+    "description": "Automatically enable Solr repositories.",
+    "defaultValue": true,
+  },
+  {
+    "name": "spring.jmx.enabled",
+    "dataType": "java.lang.Boolean",
+    "description": "Automatically expose management beans to the JMX domain",
+    "defaultValue": true,
+  },
+  {
+    "name": "spring.jpa.open-in-view",
+    "dataType": "java.lang.Boolean",
+    "description": "Automatically register OpenEntityManagerInViewInterceptor. Binds a JPA EntityManager to the thread for the entire processing of the request.",
+    "defaultValue": true,
+  },
+  {
+    "name": "spring.mobile.devicedelegatingviewresolver.enabled",
+    "dataType": "java.lang.Boolean",
+    "description": "Enable device view resolver.",
+    "defaultValue": false,
+  },
+  {
+    "name": "spring.mobile.sitepreference.enabled",
+    "dataType": "java.lang.Boolean",
+    "description": "Enable SitePreferenceHandler.",
+    "defaultValue": true,
+  },
+  {
+    "name": "spring.social.auto-connection-views",
+    "dataType": "java.lang.Boolean",
+    "description": "Automatically enable the connection status view for supported providers.",
+    "defaultValue": false,
+  },
+  {
+    "name": "spring.view.prefix",
+    "dataType": "java.lang.String",
+    "description": "Spring MVC view prefix.",
+  },
+  {
+    "name": "spring.view.suffix",
+    "dataType": "java.lang.String",
+    "description": "Spring MVC view suffix.",
+  }
+]}
+