Allow access to applied property sources

Add PropertySourcesPlaceholderConfigurer.getAppliedPropertySources() to
allow access to the PropertySources that were actually applied.

Issue: SPR-10545

Author: philwebb

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -31,6 +31,7 @@
 import org.springframework.core.env.PropertySource;
 import org.springframework.core.env.PropertySources;
 import org.springframework.core.env.PropertySourcesPropertyResolver;
+import org.springframework.util.Assert;
 import org.springframework.util.StringValueResolver;
 
 /**
@@ -79,6 +80,8 @@ public class PropertySourcesPlaceholderConfigurer extends PlaceholderConfigurerS
 
 	private MutablePropertySources propertySources;
 
+	private PropertySources appliedPropertySources;
+
 	private Environment environment;
 
 
@@ -149,6 +152,7 @@ public String getProperty(String key) {
 		}
 
 		this.processProperties(beanFactory, new PropertySourcesPropertyResolver(this.propertySources));
+		this.appliedPropertySources = this.propertySources;
 	}
 
 	/**
@@ -186,4 +190,16 @@ protected void processProperties(ConfigurableListableBeanFactory beanFactory, Pr
 				"Call processProperties(ConfigurableListableBeanFactory, ConfigurablePropertyResolver) instead");
 	}
 
+	/**
+	 * Returns the property sources that were actually applied during
+	 * {@link #postProcessBeanFactory(ConfigurableListableBeanFactory) post-processing}.
+	 * @return the property sources that were applied
+	 * @throws IllegalStateException if the property sources have not yet been applied
+	 * @since 4.0
+	 */
+	public PropertySources getAppliedPropertySources() throws IllegalStateException {
+		Assert.state(this.appliedPropertySources != null, "PropertySources have not get been applied");
+		return this.appliedPropertySources;
+	}
+
 }

spring-context/src/test/java/org/springframework/context/support/PropertySourcesPlaceholderConfigurerTests.java

@@ -16,28 +16,26 @@
 
 package org.springframework.context.support;
 
-import static org.hamcrest.CoreMatchers.equalTo;
-import static org.hamcrest.CoreMatchers.is;
-import static org.hamcrest.CoreMatchers.nullValue;
-import static org.junit.Assert.assertThat;
-import static org.springframework.beans.factory.support.BeanDefinitionBuilder.genericBeanDefinition;
-import static org.springframework.beans.factory.support.BeanDefinitionBuilder.rootBeanDefinition;
-
 import java.util.Properties;
 
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
 import org.springframework.beans.factory.BeanDefinitionStoreException;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
-import org.springframework.core.env.StandardEnvironment;
 import org.springframework.core.env.MutablePropertySources;
 import org.springframework.core.env.PropertySource;
+import org.springframework.core.env.StandardEnvironment;
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
 import org.springframework.mock.env.MockEnvironment;
 import org.springframework.mock.env.MockPropertySource;
-
 import org.springframework.tests.sample.beans.TestBean;
 
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+import static org.springframework.beans.factory.support.BeanDefinitionBuilder.*;
+
 /**
  * Unit tests for {@link PropertySourcesPlaceholderConfigurer}.
  *
@@ -46,6 +44,9 @@
  */
 public class PropertySourcesPlaceholderConfigurerTests {
 
+	@Rule
+	public ExpectedException thrown = ExpectedException.none();
+
 	@Test
 	public void replacementFromEnvironmentProperties() {
 		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
@@ -62,6 +63,7 @@ public void replacementFromEnvironmentProperties() {
 		ppc.setEnvironment(env);
 		ppc.postProcessBeanFactory(bf);
 		assertThat(bf.getBean(TestBean.class).getName(), equalTo("myValue"));
+		assertThat(ppc.getAppliedPropertySources(), not(nullValue()));
 	}
 
 	@Test
@@ -104,6 +106,7 @@ public void explicitPropertySources() {
 		pc.setPropertySources(propertySources);
 		pc.postProcessBeanFactory(bf);
 		assertThat(bf.getBean(TestBean.class).getName(), equalTo("foo"));
+		assertEquals(pc.getAppliedPropertySources().iterator().next(), propertySources.iterator().next());
 	}
 
 	@Test
@@ -123,6 +126,7 @@ public void explicitPropertySourcesExcludesEnvironment() {
 		pc.setIgnoreUnresolvablePlaceholders(true);
 		pc.postProcessBeanFactory(bf);
 		assertThat(bf.getBean(TestBean.class).getName(), equalTo("${my.name}"));
+		assertEquals(pc.getAppliedPropertySources().iterator().next(), propertySources.iterator().next());
 	}
 
 	@Test
@@ -254,4 +258,11 @@ public void nullValueIsPreserved() {
 		ppc.postProcessBeanFactory(bf);
 		assertThat(bf.getBean(TestBean.class).getName(), nullValue());
 	}
+
+	@Test
+	public void getAppliedPropertySourcesTooEarly() throws Exception {
+		PropertySourcesPlaceholderConfigurer ppc = new PropertySourcesPlaceholderConfigurer();
+		thrown.expect(IllegalStateException.class);
+		ppc.getAppliedPropertySources();
+	}
 }