GenericFilterBean lazily initializes its default environment

Alignment with HttpServletBean; consistent use of EnvironmentCapable.

Issue: SPR-15469

Author: jhoeller

spring-context/src/main/java/org/springframework/context/ConfigurableApplicationContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -103,18 +103,19 @@ public interface ConfigurableApplicationContext extends ApplicationContext, Life
 	void setParent(ApplicationContext parent);
 
 	/**
-	 * Return the Environment for this application context in configurable form.
+	 * Set the {@code Environment} for this application context.
+	 * @param environment the new environment
 	 * @since 3.1
 	 */
-	@Override
-	ConfigurableEnvironment getEnvironment();
+	void setEnvironment(ConfigurableEnvironment environment);
 
 	/**
-	 * Set the {@code Environment} for this application context.
-	 * @param environment the new environment
+	 * Return the {@code Environment} for this application context in configurable
+	 * form, allowing for further customization.
 	 * @since 3.1
 	 */
-	void setEnvironment(ConfigurableEnvironment environment);
+	@Override
+	ConfigurableEnvironment getEnvironment();
 
 	/**
 	 * Add a new BeanFactoryPostProcessor that will get applied to the internal

spring-context/src/main/java/org/springframework/context/EnvironmentAware.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -25,11 +25,12 @@
  *
  * @author Chris Beams
  * @since 3.1
+ * @see org.springframework.core.env.EnvironmentCapable
  */
 public interface EnvironmentAware extends Aware {
 
 	/**
-	 * Set the {@code Environment} that this object runs in.
+	 * Set the {@code Environment} that this component runs in.
 	 */
 	void setEnvironment(Environment environment);
 

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

@@ -280,8 +280,22 @@ public ApplicationContext getParent() {
 	}
 
 	/**
-	 * {@inheritDoc}
-	 * <p>If {@code null}, a new environment will be initialized via
+	 * Set the {@code Environment} for this application context.
+	 * <p>Default value is determined by {@link #createEnvironment()}. Replacing the
+	 * default with this method is one option but configuration through {@link
+	 * #getEnvironment()} should also be considered. In either case, such modifications
+	 * should be performed <em>before</em> {@link #refresh()}.
+	 * @see org.springframework.context.support.AbstractApplicationContext#createEnvironment
+	 */
+	@Override
+	public void setEnvironment(ConfigurableEnvironment environment) {
+		this.environment = environment;
+	}
+
+	/**
+	 * Return the {@code Environment} for this application context in configurable
+	 * form, allowing for further customization.
+	 * <p>If none specified, a default environment will be initialized via
 	 * {@link #createEnvironment()}.
 	 */
 	@Override
@@ -293,16 +307,12 @@ public ConfigurableEnvironment getEnvironment() {
 	}
 
 	/**
-	 * {@inheritDoc}
-	 * <p>Default value is determined by {@link #createEnvironment()}. Replacing the
-	 * default with this method is one option but configuration through {@link
-	 * #getEnvironment()} should also be considered. In either case, such modifications
-	 * should be performed <em>before</em> {@link #refresh()}.
-	 * @see org.springframework.context.support.AbstractApplicationContext#createEnvironment
+	 * Create and return a new {@link StandardEnvironment}.
+	 * <p>Subclasses may override this method in order to supply
+	 * a custom {@link ConfigurableEnvironment} implementation.
 	 */
-	@Override
-	public void setEnvironment(ConfigurableEnvironment environment) {
-		this.environment = environment;
+	protected ConfigurableEnvironment createEnvironment() {
+		return new StandardEnvironment();
 	}
 
 	/**
@@ -443,7 +453,7 @@ protected ResourcePatternResolver getResourcePatternResolver() {
 	//---------------------------------------------------------------------
 
 	/**
-	 * {@inheritDoc}
+	 * Set the parent of this application context.
 	 * <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
@@ -494,15 +504,6 @@ public Collection<ApplicationListener<?>> getApplicationListeners() {
 		return this.applicationListeners;
 	}
 
-	/**
-	 * Create and return a new {@link StandardEnvironment}.
-	 * <p>Subclasses may override this method in order to supply
-	 * a custom {@link ConfigurableEnvironment} implementation.
-	 */
-	protected ConfigurableEnvironment createEnvironment() {
-		return new StandardEnvironment();
-	}
-
 	@Override
 	public void refresh() throws BeansException, IllegalStateException {
 		synchronized (this.startupShutdownMonitor) {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -41,7 +41,8 @@
 public interface EnvironmentCapable {
 
 	/**
-	 * Return the {@link Environment} associated with this component.
+	 * Return the {@link Environment} associated with this component
+	 * (may be {@code null} or a default environment).
 	 */
 	Environment getEnvironment();