Avoid unnecessary creation of default StandardEnvironment instances

Issue: SPR-10568

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractBeanDefinitionReader.java

 /*
- * 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.
@@ -54,7 +54,7 @@ public abstract class AbstractBeanDefinitionReader implements EnvironmentCapable
 
 	private ClassLoader beanClassLoader;
 
-	private Environment environment = new StandardEnvironment();
+	private Environment environment;
 
 	private BeanNameGenerator beanNameGenerator = new DefaultBeanNameGenerator();
 
@@ -90,7 +90,7 @@ public abstract class AbstractBeanDefinitionReader implements EnvironmentCapable
 
 		// Inherit Environment if possible
 		if (this.registry instanceof EnvironmentCapable) {
-			this.environment = ((EnvironmentCapable)this.registry).getEnvironment();
+			this.environment = ((EnvironmentCapable) this.registry).getEnvironment();
 		}
 		else {
 			this.environment = new StandardEnvironment();

spring-beans/src/main/java/org/springframework/beans/support/ResourceEditorRegistrar.java

 /*
- * 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.
@@ -78,9 +78,12 @@ public class ResourceEditorRegistrar implements PropertyEditorRegistrar {
 	}
 
 	/**
-	 * Create a new ResourceEditorRegistrar for the given ResourceLoader
+	 * Create a new ResourceEditorRegistrar for the given {@link ResourceLoader}
+	 * and {@link PropertyResolver}.
 	 * @param resourceLoader the ResourceLoader (or ResourcePatternResolver)
 	 * to create editors for (usually an ApplicationContext)
+	 * @param propertyResolver the PropertyResolver (usually an Environment)
+	 * @see org.springframework.core.env.Environment
 	 * @see org.springframework.core.io.support.ResourcePatternResolver
 	 * @see org.springframework.context.ApplicationContext
 	 */

spring-context/src/main/java/org/springframework/context/annotation/ClassPathScanningCandidateComponentProvider.java

 /*
- * 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.
@@ -90,7 +90,7 @@ public class ClassPathScanningCandidateComponentProvider implements EnvironmentC
 
 
 	/**
-	 * Create a ClassPathScanningCandidateComponentProvider.
+	 * Create a ClassPathScanningCandidateComponentProvider with a {@link StandardEnvironment}.
 	 * @param useDefaultFilters whether to register the default filters for the
 	 * {@link Component @Component}, {@link Repository @Repository},
 	 * {@link Service @Service}, and {@link Controller @Controller}
@@ -101,6 +101,15 @@ public class ClassPathScanningCandidateComponentProvider implements EnvironmentC
 		this(useDefaultFilters, new StandardEnvironment());
 	}
 
+	/**
+	 * Create a ClassPathScanningCandidateComponentProvider with the given {@link Environment}.
+	 * @param useDefaultFilters whether to register the default filters for the
+	 * {@link Component @Component}, {@link Repository @Repository},
+	 * {@link Service @Service}, and {@link Controller @Controller}
+	 * stereotype annotations
+	 * @param environment the Environment to use
+	 * @see #registerDefaultFilters()
+	 */
 	public ClassPathScanningCandidateComponentProvider(boolean useDefaultFilters, Environment environment) {
 		if (useDefaultFilters) {
 			registerDefaultFilters();

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

 /*
- * 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.
@@ -452,7 +452,7 @@ public abstract class AbstractEnvironment implements ConfigurableEnvironment {
 	@Override
 	public <T> T getProperty(String key, Class<T> targetType, T defaultValue) {
 		return this.propertyResolver.getProperty(key, targetType, defaultValue);
-	};
+	}
 
 	@Override
 	public <T> Class<T> getPropertyAsClass(String key, Class<T> targetType) {

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

 /*
- * 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.
@@ -16,8 +16,6 @@
 
 package org.springframework.core.env;
 
-import static java.lang.String.format;
-
 import org.springframework.core.convert.ConversionException;
 import org.springframework.util.ClassUtils;
 
@@ -35,6 +33,7 @@ public class PropertySourcesPropertyResolver extends AbstractPropertyResolver {
 
 	private final PropertySources propertySources;
 
+
 	/**
 	 * Create a new resolver against the given property sources.
 	 * @param propertySources the set of {@link PropertySource} objects to use
@@ -43,11 +42,14 @@ public class PropertySourcesPropertyResolver extends AbstractPropertyResolver {
 		this.propertySources = propertySources;
 	}
 
+
 	@Override
 	public boolean containsProperty(String key) {
-		for (PropertySource<?> propertySource : this.propertySources) {
-			if (propertySource.containsProperty(key)) {
-				return true;
+		if (this.propertySources != null) {
+			for (PropertySource<?> propertySource : this.propertySources) {
+				if (propertySource.containsProperty(key)) {
+					return true;
+				}
 			}
 		}
 		return false;
@@ -55,45 +57,41 @@ public class PropertySourcesPropertyResolver extends AbstractPropertyResolver {
 
 	@Override
 	public String getProperty(String key) {
-		if (logger.isTraceEnabled()) {
-			logger.trace(format("getProperty(\"%s\") (implicit targetType [String])", key));
-		}
-		return this.getProperty(key, String.class);
+		return getProperty(key, String.class);
 	}
 
 	@Override
 	public <T> T getProperty(String key, Class<T> targetValueType) {
 		boolean debugEnabled = logger.isDebugEnabled();
 		if (logger.isTraceEnabled()) {
-			logger.trace(format("getProperty(\"%s\", %s)", key, targetValueType.getSimpleName()));
+			logger.trace(String.format("getProperty(\"%s\", %s)", key, targetValueType.getSimpleName()));
 		}
-
-		for (PropertySource<?> propertySource : this.propertySources) {
-			if (debugEnabled) {
-				logger.debug(format("Searching for key '%s' in [%s]", key, propertySource.getName()));
-			}
-			Object value;
-			if ((value = propertySource.getProperty(key)) != null) {
-				Class<?> valueType = value.getClass();
-				if (String.class.equals(valueType)) {
-					value = this.resolveNestedPlaceholders((String) value);
-				}
+		if (this.propertySources != null) {
+			for (PropertySource<?> propertySource : this.propertySources) {
 				if (debugEnabled) {
-					logger.debug(
-							format("Found key '%s' in [%s] with type [%s] and value '%s'",
-									key, propertySource.getName(), valueType.getSimpleName(), value));
+					logger.debug(String.format("Searching for key '%s' in [%s]", key, propertySource.getName()));
 				}
-				if (!this.conversionService.canConvert(valueType, targetValueType)) {
-					throw new IllegalArgumentException(
-							format("Cannot convert value [%s] from source type [%s] to target type [%s]",
-									value, valueType.getSimpleName(), targetValueType.getSimpleName()));
+				Object value;
+				if ((value = propertySource.getProperty(key)) != null) {
+					Class<?> valueType = value.getClass();
+					if (String.class.equals(valueType)) {
+						value = this.resolveNestedPlaceholders((String) value);
+					}
+					if (debugEnabled) {
+						logger.debug(String.format("Found key '%s' in [%s] with type [%s] and value '%s'",
+								key, propertySource.getName(), valueType.getSimpleName(), value));
+					}
+					if (!this.conversionService.canConvert(valueType, targetValueType)) {
+						throw new IllegalArgumentException(String.format(
+								"Cannot convert value [%s] from source type [%s] to target type [%s]",
+								value, valueType.getSimpleName(), targetValueType.getSimpleName()));
+					}
+					return conversionService.convert(value, targetValueType);
 				}
-				return conversionService.convert(value, targetValueType);
 			}
 		}
-
 		if (debugEnabled) {
-			logger.debug(format("Could not find key '%s' in any property source. Returning [null]", key));
+			logger.debug(String.format("Could not find key '%s' in any property source. Returning [null]", key));
 		}
 		return null;
 	}
@@ -102,51 +100,52 @@ public class PropertySourcesPropertyResolver extends AbstractPropertyResolver {
 	public <T> Class<T> getPropertyAsClass(String key, Class<T> targetValueType) {
 		boolean debugEnabled = logger.isDebugEnabled();
 		if (logger.isTraceEnabled()) {
-			logger.trace(format("getPropertyAsClass(\"%s\", %s)", key, targetValueType.getSimpleName()));
+			logger.trace(String.format("getPropertyAsClass(\"%s\", %s)", key, targetValueType.getSimpleName()));
 		}
-
-		for (PropertySource<?> propertySource : this.propertySources) {
-			if (debugEnabled) {
-				logger.debug(format("Searching for key '%s' in [%s]", key, propertySource.getName()));
-			}
-			Object value;
-			if ((value = propertySource.getProperty(key)) != null) {
+		if (this.propertySources != null) {
+			for (PropertySource<?> propertySource : this.propertySources) {
 				if (debugEnabled) {
-					logger.debug(
-							format("Found key '%s' in [%s] with value '%s'", key, propertySource.getName(), value));
+					logger.debug(String.format("Searching for key '%s' in [%s]", key, propertySource.getName()));
 				}
-
-				Class<?> clazz;
-				if (value instanceof String) {
-					try {
-						clazz = ClassUtils.forName((String)value, null);
-					} catch (Exception ex) {
-						throw new ClassConversionException((String)value, targetValueType, ex);
+				Object value = propertySource.getProperty(key);
+				if (value != null) {
+					if (debugEnabled) {
+						logger.debug(String.format("Found key '%s' in [%s] with value '%s'", key, propertySource.getName(), value));
 					}
+					Class<?> clazz;
+					if (value instanceof String) {
+						try {
+							clazz = ClassUtils.forName((String)value, null);
+						}
+						catch (Exception ex) {
+							throw new ClassConversionException((String)value, targetValueType, ex);
+						}
+					}
+					else if (value instanceof Class) {
+						clazz = (Class<?>)value;
+					}
+					else {
+						clazz = value.getClass();
+					}
+					if (!targetValueType.isAssignableFrom(clazz)) {
+						throw new ClassConversionException(clazz, targetValueType);
+					}
+					@SuppressWarnings("unchecked")
+					Class<T> targetClass = (Class<T>) clazz;
+					return targetClass;
 				}
-				else if (value instanceof Class) {
-					clazz = (Class<?>)value;
-				} else {
-					clazz = value.getClass();
-				}
-
-				if (!targetValueType.isAssignableFrom(clazz)) {
-					throw new ClassConversionException(clazz, targetValueType);
-				}
-				@SuppressWarnings("unchecked")
-				Class<T> targetClass = (Class<T>)clazz;
-				return targetClass;
 			}
 		}
-
 		if (debugEnabled) {
-			logger.debug(format("Could not find key '%s' in any property source. Returning [null]", key));
+			logger.debug(String.format("Could not find key '%s' in any property source. Returning [null]", key));
 		}
 		return null;
 	}
 
+
 	@SuppressWarnings("serial")
-	static class ClassConversionException extends ConversionException {
+	private static class ClassConversionException extends ConversionException {
+
 		public ClassConversionException(Class<?> actual, Class<?> expected) {
 			super(String.format("Actual type %s is not assignable to expected type %s", actual.getName(), expected.getName()));
 		}
@@ -155,4 +154,5 @@ public class PropertySourcesPropertyResolver extends AbstractPropertyResolver {
 			super(String.format("Could not find/load class %s during attempt to convert to %s", actual, expected.getName()), ex);
 		}
 	}
+
 }

spring-core/src/main/java/org/springframework/core/io/ResourceEditor.java

 /*
- * 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.
@@ -19,12 +19,11 @@ package org.springframework.core.io;
 import java.beans.PropertyEditorSupport;
 import java.io.IOException;
 
-import org.springframework.core.env.StandardEnvironment;
 import org.springframework.core.env.PropertyResolver;
+import org.springframework.core.env.StandardEnvironment;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
-
 /**
  * {@link java.beans.PropertyEditor Editor} for {@link Resource}
  * descriptors, to automatically convert {@code String} locations
@@ -51,7 +50,7 @@ public class ResourceEditor extends PropertyEditorSupport {
 
 	private final ResourceLoader resourceLoader;
 
-	private final PropertyResolver propertyResolver;
+	private PropertyResolver propertyResolver;
 
 	private final boolean ignoreUnresolvablePlaceholders;
 
@@ -61,7 +60,7 @@ public class ResourceEditor extends PropertyEditorSupport {
 	 * using a {@link DefaultResourceLoader} and {@link StandardEnvironment}.
 	 */
 	public ResourceEditor() {
-		this(new DefaultResourceLoader(), new StandardEnvironment());
+		this(new DefaultResourceLoader(), null);
 	}
 
 	/**
@@ -73,17 +72,7 @@ public class ResourceEditor extends PropertyEditorSupport {
 	 */
 	@Deprecated
 	public ResourceEditor(ResourceLoader resourceLoader) {
-		this(resourceLoader, new StandardEnvironment(), true);
-	}
-
-	/**
-	 * Create a new instance of the {@link ResourceEditor} class
-	 * using the given {@link ResourceLoader} and {@link PropertyResolver}.
-	 * @param resourceLoader the {@code ResourceLoader} to use
-	 * @param propertyResolver the {@code PropertyResolver} to use
-	 */
-	public ResourceEditor(ResourceLoader resourceLoader, PropertyResolver propertyResolver) {
-		this(resourceLoader, propertyResolver, true);
+		this(resourceLoader, null, true);
 	}
 
 	/**
@@ -97,7 +86,17 @@ public class ResourceEditor extends PropertyEditorSupport {
 	 */
 	@Deprecated
 	public ResourceEditor(ResourceLoader resourceLoader, boolean ignoreUnresolvablePlaceholders) {
-		this(resourceLoader, new StandardEnvironment(), ignoreUnresolvablePlaceholders);
+		this(resourceLoader, null, ignoreUnresolvablePlaceholders);
+	}
+
+	/**
+	 * Create a new instance of the {@link ResourceEditor} class
+	 * using the given {@link ResourceLoader} and {@link PropertyResolver}.
+	 * @param resourceLoader the {@code ResourceLoader} to use
+	 * @param propertyResolver the {@code PropertyResolver} to use
+	 */
+	public ResourceEditor(ResourceLoader resourceLoader, PropertyResolver propertyResolver) {
+		this(resourceLoader, propertyResolver, true);
 	}
 
 	/**
@@ -110,7 +109,6 @@ public class ResourceEditor extends PropertyEditorSupport {
 	 */
 	public ResourceEditor(ResourceLoader resourceLoader, PropertyResolver propertyResolver, boolean ignoreUnresolvablePlaceholders) {
 		Assert.notNull(resourceLoader, "ResourceLoader must not be null");
-		Assert.notNull(propertyResolver, "PropertyResolver must not be null");
 		this.resourceLoader = resourceLoader;
 		this.propertyResolver = propertyResolver;
 		this.ignoreUnresolvablePlaceholders = ignoreUnresolvablePlaceholders;
@@ -137,9 +135,11 @@ public class ResourceEditor extends PropertyEditorSupport {
 	 * @see PropertyResolver#resolveRequiredPlaceholders
 	 */
 	protected String resolvePath(String path) {
-		return this.ignoreUnresolvablePlaceholders ?
-				this.propertyResolver.resolvePlaceholders(path) :
-				this.propertyResolver.resolveRequiredPlaceholders(path);
+		if (this.propertyResolver == null) {
+			this.propertyResolver = new StandardEnvironment();
+		}
+		return (this.ignoreUnresolvablePlaceholders ? this.propertyResolver.resolvePlaceholders(path) :
+				this.propertyResolver.resolveRequiredPlaceholders(path));
 	}
 
 

spring-core/src/main/java/org/springframework/core/io/support/ResourceArrayPropertyEditor.java

 /*
- * 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.
@@ -25,10 +25,12 @@ import java.util.List;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.springframework.core.env.StandardEnvironment;
+
 import org.springframework.core.env.Environment;
 import org.springframework.core.env.PropertyResolver;
+import org.springframework.core.env.StandardEnvironment;
 import org.springframework.core.io.Resource;
+import org.springframework.util.Assert;
 
 /**
  * Editor for {@link org.springframework.core.io.Resource} arrays, to
@@ -55,10 +57,10 @@ public class ResourceArrayPropertyEditor extends PropertyEditorSupport {
 
 	private static final Log logger = LogFactory.getLog(ResourceArrayPropertyEditor.class);
 
-	private final PropertyResolver propertyResolver;
-
 	private final ResourcePatternResolver resourcePatternResolver;
 
+	private PropertyResolver propertyResolver;
+
 	private final boolean ignoreUnresolvablePlaceholders;
 
 
@@ -69,7 +71,7 @@ public class ResourceArrayPropertyEditor extends PropertyEditorSupport {
 	 * @see Environment
 	 */
 	public ResourceArrayPropertyEditor() {
-		this(new PathMatchingResourcePatternResolver(), new StandardEnvironment(), true);
+		this(new PathMatchingResourcePatternResolver(), null, true);
 	}
 
 	/**
@@ -80,17 +82,7 @@ public class ResourceArrayPropertyEditor extends PropertyEditorSupport {
 	 */
 	@Deprecated
 	public ResourceArrayPropertyEditor(ResourcePatternResolver resourcePatternResolver) {
-		this(resourcePatternResolver, new StandardEnvironment(), true);
-	}
-
-	/**
-	 * Create a new ResourceArrayPropertyEditor with the given {@link ResourcePatternResolver}
-	 * and {@link PropertyResolver} (typically an {@link Environment}).
-	 * @param resourcePatternResolver the ResourcePatternResolver to use
-	 * @param propertyResolver the PropertyResolver to use
-	 */
-	public ResourceArrayPropertyEditor(ResourcePatternResolver resourcePatternResolver, PropertyResolver propertyResolver) {
-		this(resourcePatternResolver, propertyResolver, true);
+		this(resourcePatternResolver, null, true);
 	}
 
 	/**
@@ -103,7 +95,17 @@ public class ResourceArrayPropertyEditor extends PropertyEditorSupport {
 	 */
 	@Deprecated
 	public ResourceArrayPropertyEditor(ResourcePatternResolver resourcePatternResolver, boolean ignoreUnresolvablePlaceholders) {
-		this(resourcePatternResolver, new StandardEnvironment(), ignoreUnresolvablePlaceholders);
+		this(resourcePatternResolver, null, ignoreUnresolvablePlaceholders);
+	}
+
+	/**
+	 * Create a new ResourceArrayPropertyEditor with the given {@link ResourcePatternResolver}
+	 * and {@link PropertyResolver} (typically an {@link Environment}).
+	 * @param resourcePatternResolver the ResourcePatternResolver to use
+	 * @param propertyResolver the PropertyResolver to use
+	 */
+	public ResourceArrayPropertyEditor(ResourcePatternResolver resourcePatternResolver, PropertyResolver propertyResolver) {
+		this(resourcePatternResolver, propertyResolver, true);
 	}
 
 	/**
@@ -116,6 +118,8 @@ public class ResourceArrayPropertyEditor extends PropertyEditorSupport {
 	 */
 	public ResourceArrayPropertyEditor(ResourcePatternResolver resourcePatternResolver,
 			PropertyResolver propertyResolver, boolean ignoreUnresolvablePlaceholders) {
+
+		Assert.notNull(resourcePatternResolver, "ResourcePatternResolver must not be null");
 		this.resourcePatternResolver = resourcePatternResolver;
 		this.propertyResolver = propertyResolver;
 		this.ignoreUnresolvablePlaceholders = ignoreUnresolvablePlaceholders;
@@ -197,9 +201,11 @@ public class ResourceArrayPropertyEditor extends PropertyEditorSupport {
 	 * @see PropertyResolver#resolveRequiredPlaceholders(String)
 	 */
 	protected String resolvePath(String path) {
-		return this.ignoreUnresolvablePlaceholders ?
-				this.propertyResolver.resolvePlaceholders(path) :
-				this.propertyResolver.resolveRequiredPlaceholders(path);
+		if (this.propertyResolver == null) {
+			this.propertyResolver = new StandardEnvironment();
+		}
+		return (this.ignoreUnresolvablePlaceholders ? this.propertyResolver.resolvePlaceholders(path) :
+				this.propertyResolver.resolveRequiredPlaceholders(path));
 	}
 
 }