Merge branch cbeams/SPR-9439

* SPR-9439:
  Introduce ConfigurableWebEnvironment
  Introduce ConfigurableEnvironment#merge
  Polish

spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java

@@ -378,14 +378,19 @@ protected ResourcePatternResolver getResourcePatternResolver() {
 
 	/**
 	 * {@inheritDoc}
-	 * <p>The parent {@linkplain #getEnvironment() environment} is
-	 * delegated to this (child) context if the parent is a
-	 * {@link ConfigurableApplicationContext} implementation.
+	 * <p>The parent {@linkplain ApplicationContext#getEnvironment() environment} is
+	 * {@linkplain ConfigurableEnvironment#merge(ConfigurableEnvironment) merged} with
+	 * this (child) application context environment if the parent is non-{@code null} and
+	 * its environment is an instance of {@link ConfigurableEnvironment}.
+	 * @see ConfigurableEnvironment#merge(ConfigurableEnvironment)
 	 */
 	public void setParent(ApplicationContext parent) {
 		this.parent = parent;
-		if (parent instanceof ConfigurableApplicationContext) {
-			this.setEnvironment(((ConfigurableApplicationContext)parent).getEnvironment());
+		if (parent != null) {
+			Object parentEnvironment =  parent.getEnvironment();
+			if (parentEnvironment instanceof ConfigurableEnvironment) {
+				this.environment.merge((ConfigurableEnvironment)parentEnvironment);
+			}
 		}
 	}
 

spring-core/src/main/java/org/springframework/core/env/AbstractEnvironment.java

@@ -387,6 +387,20 @@ protected String getSystemAttribute(String propertyName) {
 		return systemProperties;
 	}
 
+	public void merge(ConfigurableEnvironment parent) {
+		for (PropertySource<?> ps : parent.getPropertySources()) {
+			if (!this.propertySources.contains(ps.getName())) {
+				this.propertySources.addLast(ps);
+			}
+		}
+		for (String profile : parent.getActiveProfiles()) {
+			this.activeProfiles.add(profile);
+		}
+		for (String profile : parent.getDefaultProfiles()) {
+			this.defaultProfiles.add(profile);
+		}
+	}
+
 
 	//---------------------------------------------------------------------
 	// Implementation of ConfigurablePropertyResolver interface

spring-core/src/main/java/org/springframework/core/env/ConfigurableEnvironment.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -55,13 +55,14 @@
  *   propertySources.replace(StandardEnvironment.SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME, mockEnvVars);
  * </pre>
  *
- * When an {@link Environment} is being used by an ApplicationContext, it is important
- * that any such PropertySource manipulations be performed <em>before</em> the context's
- * {@link org.springframework.context.support.AbstractApplicationContext#refresh()
- * refresh()} method is called. This ensures that all property sources are available
- * during the container bootstrap process, including use by
- * {@linkplain org.springframework.context.support.PropertySourcesPlaceholderConfigurer
- * property placeholder configurers}.
+ * When an {@link Environment} is being used by an {@code ApplicationContext}, it is
+ * important that any such {@code PropertySource} manipulations be performed
+ * <em>before</em> the context's {@link
+ * org.springframework.context.support.AbstractApplicationContext#refresh() refresh()}
+ * method is called. This ensures that all property sources are available during the
+ * container bootstrap process, including use by {@linkplain
+ * org.springframework.context.support.PropertySourcesPlaceholderConfigurer property
+ * placeholder configurers}.
  *
  *
  * @author Chris Beams
@@ -78,7 +79,6 @@ public interface ConfigurableEnvironment extends Environment, ConfigurableProper
 	 * <p>Any existing active profiles will be replaced with the given arguments; call
 	 * with zero arguments to clear the current set of active profiles. Use
 	 * {@link #addActiveProfile} to add a profile while preserving the existing set.
-	 *
 	 * @see #addActiveProfile
 	 * @see #setDefaultProfiles
 	 * @see org.springframework.context.annotation.Profile
@@ -123,12 +123,10 @@ public interface ConfigurableEnvironment extends Environment, ConfigurableProper
 	 * Return the value of {@link System#getenv()} if allowed by the current
 	 * {@link SecurityManager}, otherwise return a map implementation that will attempt
 	 * to access individual keys using calls to {@link System#getenv(String)}.
-	 *
 	 * <p>Note that most {@link Environment} implementations will include this system
 	 * environment map as a default {@link PropertySource} to be searched. Therefore, it
 	 * is recommended that this method not be used directly unless bypassing other
 	 * property sources is expressly intended.
-	 *
 	 * <p>Calls to {@link Map#get(Object)} on the Map returned will never throw
 	 * {@link IllegalAccessException}; in cases where the SecurityManager forbids access
 	 * to a property, {@code null} will be returned and an INFO-level log message will be
@@ -140,17 +138,35 @@ public interface ConfigurableEnvironment extends Environment, ConfigurableProper
 	 * Return the value of {@link System#getProperties()} if allowed by the current
 	 * {@link SecurityManager}, otherwise return a map implementation that will attempt
 	 * to access individual keys using calls to {@link System#getProperty(String)}.
-	 *
 	 * <p>Note that most {@code Environment} implementations will include this system
 	 * properties map as a default {@link PropertySource} to be searched. Therefore, it is
 	 * recommended that this method not be used directly unless bypassing other property
 	 * sources is expressly intended.
-	 *
 	 * <p>Calls to {@link Map#get(Object)} on the Map returned will never throw
 	 * {@link IllegalAccessException}; in cases where the SecurityManager forbids access
 	 * to a property, {@code null} will be returned and an INFO-level log message will be
 	 * issued noting the exception.
 	 */
 	Map<String, Object> getSystemProperties();
 
+	/**
+	 * Append the given parent environment's active profiles, default profiles and
+	 * property sources to this (child) environment's respective collections of each.
+	 * <p>For any identically-named {@code PropertySource} instance existing in both
+	 * parent and child, the child instance is to be preserved and the parent instance
+	 * discarded. This has the effect of allowing overriding of property sources by the
+	 * child as well as avoiding redundant searches through common property source types,
+	 * e.g. system environment and system properties.
+	 * <p>Active and default profile names are also filtered for duplicates, to avoid
+	 * confusion and redundant storage.
+	 * <p>The parent environment remains unmodified in any case. Note that any changes to
+	 * the parent environment occurring after the call to {@code merge} will not be
+	 * reflected in the child. Therefore, care should be taken to configure parent
+	 * property sources and profile information prior to calling {@code merge}.
+	 * @param parent the environment to merge with
+	 * @since 3.2
+	 * @see org.springframework.context.support.AbstractApplicationContext#setParent
+	 */
+	void merge(ConfigurableEnvironment parent);
+
 }

spring-core/src/main/java/org/springframework/util/Assert.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 the original author or authors.
+ * Copyright 2002-2012 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
@@ -335,7 +335,7 @@ public static void isInstanceOf(Class type, Object obj, String message) {
 		notNull(type, "Type to check against must not be null");
 		if (!type.isInstance(obj)) {
 			throw new IllegalArgumentException(message +
-					"Object of class [" + (obj != null ? obj.getClass().getName() : "null") +
+					". Object of class [" + (obj != null ? obj.getClass().getName() : "null") +
 					"] must be an instance of " + type);
 		}
 	}

spring-core/src/test/java/org/springframework/core/env/StandardEnvironmentTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -16,22 +16,6 @@
 
 package org.springframework.core.env;
 
-import static java.lang.String.format;
-import static org.hamcrest.CoreMatchers.equalTo;
-import static org.hamcrest.CoreMatchers.instanceOf;
-import static org.hamcrest.CoreMatchers.is;
-import static org.hamcrest.CoreMatchers.not;
-import static org.hamcrest.CoreMatchers.notNullValue;
-import static org.hamcrest.CoreMatchers.nullValue;
-import static org.junit.Assert.assertSame;
-import static org.junit.Assert.assertThat;
-import static org.junit.Assert.fail;
-import static org.junit.matchers.JUnitMatchers.hasItem;
-import static org.junit.matchers.JUnitMatchers.hasItems;
-import static org.springframework.core.env.AbstractEnvironment.ACTIVE_PROFILES_PROPERTY_NAME;
-import static org.springframework.core.env.AbstractEnvironment.DEFAULT_PROFILES_PROPERTY_NAME;
-import static org.springframework.core.env.AbstractEnvironment.RESERVED_DEFAULT_PROFILE_NAME;
-
 import java.lang.reflect.Field;
 import java.security.AccessControlException;
 import java.security.Permission;
@@ -40,8 +24,18 @@
 import java.util.Map;
 
 import org.junit.Test;
+
 import org.springframework.mock.env.MockPropertySource;
 
+import static java.lang.String.*;
+
+import static org.hamcrest.CoreMatchers.*;
+
+import static org.junit.Assert.*;
+import static org.junit.matchers.JUnitMatchers.*;
+
+import static org.springframework.core.env.AbstractEnvironment.*;
+
 /**
  * Unit tests for {@link StandardEnvironment}.
  *
@@ -62,6 +56,47 @@ public class StandardEnvironmentTests {
 
 	private ConfigurableEnvironment environment = new StandardEnvironment();
 
+	@Test
+	public void merge() {
+		ConfigurableEnvironment child = new StandardEnvironment();
+		child.setActiveProfiles("c1", "c2");
+		child.getPropertySources().addLast(
+				new MockPropertySource("childMock")
+					.withProperty("childKey", "childVal")
+					.withProperty("bothKey", "childBothVal"));
+
+		ConfigurableEnvironment parent = new StandardEnvironment();
+		parent.setActiveProfiles("p1", "p2");
+		parent.getPropertySources().addLast(
+				new MockPropertySource("parentMock")
+					.withProperty("parentKey", "parentVal")
+					.withProperty("bothKey", "parentBothVal"));
+
+		assertThat(child.getProperty("childKey"), is("childVal"));
+		assertThat(child.getProperty("parentKey"), nullValue());
+		assertThat(child.getProperty("bothKey"), is("childBothVal"));
+
+		assertThat(parent.getProperty("childKey"), nullValue());
+		assertThat(parent.getProperty("parentKey"), is("parentVal"));
+		assertThat(parent.getProperty("bothKey"), is("parentBothVal"));
+
+		assertThat(child.getActiveProfiles(), equalTo(new String[]{"c1","c2"}));
+		assertThat(parent.getActiveProfiles(), equalTo(new String[]{"p1","p2"}));
+
+		child.merge(parent);
+
+		assertThat(child.getProperty("childKey"), is("childVal"));
+		assertThat(child.getProperty("parentKey"), is("parentVal"));
+		assertThat(child.getProperty("bothKey"), is("childBothVal"));
+
+		assertThat(parent.getProperty("childKey"), nullValue());
+		assertThat(parent.getProperty("parentKey"), is("parentVal"));
+		assertThat(parent.getProperty("bothKey"), is("parentBothVal"));
+
+		assertThat(child.getActiveProfiles(), equalTo(new String[]{"c1","c2","p1","p2"}));
+		assertThat(parent.getActiveProfiles(), equalTo(new String[]{"p1","p2"}));
+	}
+
 	@Test
 	public void propertySourceOrder() {
 		ConfigurableEnvironment env = new StandardEnvironment();

spring-web/src/main/java/org/springframework/web/context/ConfigurableWebApplicationContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -71,6 +71,11 @@ public interface ConfigurableWebApplicationContext extends WebApplicationContext
 	 */
 	ServletConfig getServletConfig();
 
+	/**
+	 * Return the {@link ConfigurableWebEnvironment} used by this web application context.
+	 */
+	ConfigurableWebEnvironment getEnvironment();
+
 	/**
 	 * Set the namespace for this web application context,
 	 * to be used for building a default context config location.

spring-web/src/main/java/org/springframework/web/context/ConfigurableWebEnvironment.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2002-2012 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.web.context;
+
+import javax.servlet.ServletConfig;
+import javax.servlet.ServletContext;
+
+import org.springframework.core.env.ConfigurableEnvironment;
+
+/**
+ * Specialization of {@link ConfigurableEnvironment} allowing initialization of
+ * servlet-related {@link org.springframework.core.env.PropertySource} objects at the
+ * earliest moment the {@link ServletContext} and (optionally) {@link ServletConfig}
+ * become available.
+ *
+ * @author Chris Beams
+ * @since 3.1.2
+ * @see ConfigurableWebApplicationContext#getEnvironment()
+ */
+public interface ConfigurableWebEnvironment extends ConfigurableEnvironment {
+
+	/**
+	 * Replace any {@linkplain
+	 * org.springframework.core.env.PropertySource.StubPropertySource stub property source}
+	 * instances acting as placeholders with real servlet context/config property sources
+	 * using the given parameters.
+	 * @param servletContext the {@link ServletContext} (may not be {@code null})
+	 * @param servletConfig the {@link ServletContext} ({@code null} if not available)
+	 */
+	void initPropertySources(ServletContext servletContext, ServletConfig servletConfig);
+
+}

spring-web/src/main/java/org/springframework/web/context/ContextLoader.java

@@ -44,7 +44,6 @@
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
-import org.springframework.web.context.support.WebApplicationContextUtils;
 
 /**
  * Performs the actual initialization work for the root application context.
@@ -485,15 +484,9 @@ protected void customizeContext(ServletContext servletContext, ConfigurableWebAp
 			initializerInstances.add(BeanUtils.instantiateClass(initializerClass));
 		}
 
-		Collections.sort(initializerInstances, new AnnotationAwareOrderComparator());
-
-		// eagerly attempt to initialize servlet property sources in case initializers
-		// below depend on accessing context-params via the Environment API. Note that
-		// depending on application context implementation, this initialization will be
-		// attempted again during context refresh.
-		WebApplicationContextUtils.initServletPropertySources(
-				applicationContext.getEnvironment().getPropertySources(), servletContext);
+		applicationContext.getEnvironment().initPropertySources(servletContext, null);
 
+		Collections.sort(initializerInstances, new AnnotationAwareOrderComparator());
 		for (ApplicationContextInitializer<ConfigurableApplicationContext> initializer : initializerInstances) {
 			initializer.initialize(applicationContext);
 		}

spring-web/src/main/java/org/springframework/web/context/support/AbstractRefreshableWebApplicationContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -27,7 +27,9 @@
 import org.springframework.ui.context.Theme;
 import org.springframework.ui.context.ThemeSource;
 import org.springframework.ui.context.support.UiApplicationContextUtils;
+import org.springframework.util.Assert;
 import org.springframework.web.context.ConfigurableWebApplicationContext;
+import org.springframework.web.context.ConfigurableWebEnvironment;
 import org.springframework.web.context.ServletConfigAware;
 import org.springframework.web.context.ServletContextAware;
 
@@ -139,6 +141,14 @@ protected ConfigurableEnvironment createEnvironment() {
 		return new StandardServletEnvironment();
 	}
 
+	@Override
+	public ConfigurableWebEnvironment getEnvironment() {
+		ConfigurableEnvironment env = super.getEnvironment();
+		Assert.isInstanceOf(ConfigurableWebEnvironment.class, env,
+				"ConfigurableWebApplicationContext environment must be of type " +
+				"ConfigurableWebEnvironment");
+		return (ConfigurableWebEnvironment) env;
+	}
 
 	/**
 	 * Register request/session scopes, a {@link ServletContextAwareProcessor}, etc.
@@ -186,9 +196,7 @@ protected void onRefresh() {
 	@Override
 	protected void initPropertySources() {
 		super.initPropertySources();
-		WebApplicationContextUtils.initServletPropertySources(
-				this.getEnvironment().getPropertySources(), this.servletContext,
-				this.servletConfig);
+		this.getEnvironment().initPropertySources(this.servletContext, this.servletConfig);
 	}
 
 	public Theme getTheme(String themeName) {