Introduce composed annotations for web scopes

This commit introduces the following common composed annotations for
web scopes.

- @RequestScope
- @SessionScope
- @ApplicationScope

Issue: SPR-13993

spring-web/src/main/java/org/springframework/web/context/annotation/ApplicationScope.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2002-2016 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.annotation;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import org.springframework.context.annotation.Scope;
+import org.springframework.context.annotation.ScopedProxyMode;
+import org.springframework.core.annotation.AliasFor;
+
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+import static org.springframework.web.context.WebApplicationContext.SCOPE_APPLICATION;
+
+/**
+ * {@code @ApplicationScope} is a specialization of {@link Scope @Scope} for a
+ * component whose lifecycle is bound to the current web application.
+ *
+ * <p>Specifically, {@code @ApplicationScope} is a <em>composed annotation</em> that
+ * acts as a shortcut for {@code @Scope("application")} with the default
+ * {@link #proxyMode} set to {@link ScopedProxyMode#TARGET_CLASS TARGET_CLASS}.
+ *
+ * <p>{@code @ApplicationScope} may be used as a meta-annotation to create custom
+ * composed annotations.
+ *
+ * @author Sam Brannen
+ * @since 4.3
+ * @see RequestScope
+ * @see SessionScope
+ * @see org.springframework.context.annotation.Scope
+ * @see org.springframework.web.context.WebApplicationContext#SCOPE_APPLICATION
+ * @see org.springframework.web.context.support.ServletContextScope
+ * @see org.springframework.stereotype.Component
+ * @see org.springframework.context.annotation.Bean
+ */
+@Scope(SCOPE_APPLICATION)
+@Target({ TYPE, METHOD })
+@Retention(RUNTIME)
+@Documented
+public @interface ApplicationScope {
+
+	/**
+	 * Alias for {@link Scope#proxyMode}.
+	 * <p>Defaults to {@link ScopedProxyMode#TARGET_CLASS}.
+	 */
+	@AliasFor(annotation = Scope.class)
+	ScopedProxyMode proxyMode() default ScopedProxyMode.TARGET_CLASS;
+
+}

spring-web/src/main/java/org/springframework/web/context/annotation/RequestScope.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2002-2016 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.annotation;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import org.springframework.context.annotation.Scope;
+import org.springframework.context.annotation.ScopedProxyMode;
+import org.springframework.core.annotation.AliasFor;
+
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+import static org.springframework.web.context.WebApplicationContext.SCOPE_REQUEST;
+
+/**
+ * {@code @RequestScope} is a specialization of {@link Scope @Scope} for a
+ * component whose lifecycle is bound to the current web request.
+ *
+ * <p>Specifically, {@code @RequestScope} is a <em>composed annotation</em> that
+ * acts as a shortcut for {@code @Scope("request")} with the default
+ * {@link #proxyMode} set to {@link ScopedProxyMode#TARGET_CLASS TARGET_CLASS}.
+ *
+ * <p>{@code @RequestScope} may be used as a meta-annotation to create custom
+ * composed annotations.
+ *
+ * @author Sam Brannen
+ * @since 4.3
+ * @see SessionScope
+ * @see ApplicationScope
+ * @see org.springframework.context.annotation.Scope
+ * @see org.springframework.web.context.WebApplicationContext#SCOPE_REQUEST
+ * @see org.springframework.web.context.request.RequestScope
+ * @see org.springframework.stereotype.Component
+ * @see org.springframework.context.annotation.Bean
+ */
+@Scope(SCOPE_REQUEST)
+@Target({ TYPE, METHOD })
+@Retention(RUNTIME)
+@Documented
+public @interface RequestScope {
+
+	/**
+	 * Alias for {@link Scope#proxyMode}.
+	 * <p>Defaults to {@link ScopedProxyMode#TARGET_CLASS}.
+	 */
+	@AliasFor(annotation = Scope.class)
+	ScopedProxyMode proxyMode() default ScopedProxyMode.TARGET_CLASS;
+
+}

spring-web/src/main/java/org/springframework/web/context/annotation/SessionScope.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2002-2016 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.annotation;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import org.springframework.context.annotation.Scope;
+import org.springframework.context.annotation.ScopedProxyMode;
+import org.springframework.core.annotation.AliasFor;
+
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+import static org.springframework.web.context.WebApplicationContext.SCOPE_SESSION;
+
+/**
+ * {@code @SessionScope} is a specialization of {@link Scope @Scope} for a
+ * component whose lifecycle is bound to the current web session.
+ *
+ * <p>Specifically, {@code @SessionScope} is a <em>composed annotation</em> that
+ * acts as a shortcut for {@code @Scope("session")} with the default
+ * {@link #proxyMode} set to {@link ScopedProxyMode#TARGET_CLASS TARGET_CLASS}.
+ *
+ * <p>{@code @SessionScope} may be used as a meta-annotation to create custom
+ * composed annotations.
+ *
+ * @author Sam Brannen
+ * @since 4.3
+ * @see RequestScope
+ * @see ApplicationScope
+ * @see org.springframework.context.annotation.Scope
+ * @see org.springframework.web.context.WebApplicationContext#SCOPE_SESSION
+ * @see org.springframework.web.context.request.SessionScope
+ * @see org.springframework.stereotype.Component
+ * @see org.springframework.context.annotation.Bean
+ */
+@Scope(SCOPE_SESSION)
+@Target({ TYPE, METHOD })
+@Retention(RUNTIME)
+@Documented
+public @interface SessionScope {
+
+	/**
+	 * Alias for {@link Scope#proxyMode}.
+	 * <p>Defaults to {@link ScopedProxyMode#TARGET_CLASS}.
+	 */
+	@AliasFor(annotation = Scope.class)
+	ScopedProxyMode proxyMode() default ScopedProxyMode.TARGET_CLASS;
+
+}

src/asciidoc/whats-new.adoc

@@ -662,10 +662,11 @@ Spring 4.3 also improves the caching abstraction as follows:
 === Web Improvements
 
 * Built-in support for <<mvc-ann-requestmapping-head-options,HTTP HEAD and HTTP OPTIONS>>.
+* New `@RequestScope`, `@SessionScope`, and `@ApplicationScope` _composed annotations_ for web scopes.
 * New `@RestControllerAdvice` annotation with combined `@ControllerAdvice` with `@ResponseBody` semantics.
-* `@ResponseStatus` supported on the class level and inherited on all methods.
+* `@ResponseStatus` is now supported at the class level and inherited by all methods.
 * New `@SessionAttribute` annotation for access to session attributes (see <<mvc-ann-sessionattrib-global, example>>).
-* New `@RequestAttribute` annotation for access to session attributes (see <<mvc-ann-requestattrib, example>>).
+* New `@RequestAttribute` annotation for access to request attributes (see <<mvc-ann-requestattrib, example>>).
 * `@ModelAttribute` allows preventing data binding via `binding=false` attribute (see <<mvc-ann-modelattrib-method-args, reference>>).
 * `AsyncRestTemplate` supports request interception.
 

src/test/java/org/springframework/context/annotation/scope/ClassPathBeanDefinitionScannerScopeIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -17,50 +17,50 @@
 package org.springframework.context.annotation.scope;
 
 import org.junit.After;
-import static org.junit.Assert.*;
 import org.junit.Before;
 import org.junit.Test;
 
 import org.springframework.aop.support.AopUtils;
-import org.springframework.beans.factory.config.BeanDefinition;
-import org.springframework.beans.factory.support.BeanDefinitionRegistry;
-import org.springframework.beans.factory.support.BeanNameGenerator;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.ClassPathBeanDefinitionScanner;
-import org.springframework.context.annotation.Scope;
 import org.springframework.context.annotation.ScopedProxyMode;
 import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.mock.web.MockHttpSession;
 import org.springframework.stereotype.Component;
+import org.springframework.web.context.annotation.RequestScope;
+import org.springframework.web.context.annotation.SessionScope;
 import org.springframework.web.context.request.RequestContextHolder;
 import org.springframework.web.context.request.ServletRequestAttributes;
 import org.springframework.web.context.support.GenericWebApplicationContext;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.springframework.context.annotation.ScopedProxyMode.DEFAULT;
+import static org.springframework.context.annotation.ScopedProxyMode.INTERFACES;
+import static org.springframework.context.annotation.ScopedProxyMode.NO;
+import static org.springframework.context.annotation.ScopedProxyMode.TARGET_CLASS;
+
 /**
  * @author Mark Fisher
  * @author Juergen Hoeller
  * @author Chris Beams
+ * @author Sam Brannen
  */
 public class ClassPathBeanDefinitionScannerScopeIntegrationTests {
 
 	private static final String DEFAULT_NAME = "default";
-
 	private static final String MODIFIED_NAME = "modified";
 
-	private ServletRequestAttributes oldRequestAttributes;
-
-	private ServletRequestAttributes newRequestAttributes;
+	private ServletRequestAttributes oldRequestAttributes = new ServletRequestAttributes(new MockHttpServletRequest());
+	private ServletRequestAttributes newRequestAttributes = new ServletRequestAttributes(new MockHttpServletRequest());
 
 	private ServletRequestAttributes oldRequestAttributesWithSession;
-
 	private ServletRequestAttributes newRequestAttributesWithSession;
 
 
 	@Before
 	public void setUp() {
-		this.oldRequestAttributes = new ServletRequestAttributes(new MockHttpServletRequest());
-		this.newRequestAttributes = new ServletRequestAttributes(new MockHttpServletRequest());
-
 		MockHttpServletRequest oldRequestWithSession = new MockHttpServletRequest();
 		oldRequestWithSession.setSession(new MockHttpSession());
 		this.oldRequestAttributesWithSession = new ServletRequestAttributes(oldRequestWithSession);
@@ -72,14 +72,14 @@ public class ClassPathBeanDefinitionScannerScopeIntegrationTests {
 
 	@After
 	public void tearDown() throws Exception {
-		RequestContextHolder.setRequestAttributes(null);
+		RequestContextHolder.resetRequestAttributes();
 	}
 
 
 	@Test
-	public void testSingletonScopeWithNoProxy() {
+	public void singletonScopeWithNoProxy() {
 		RequestContextHolder.setRequestAttributes(oldRequestAttributes);
-		ApplicationContext context = createContext(ScopedProxyMode.NO);
+		ApplicationContext context = createContext(NO);
 		ScopedTestBean bean = (ScopedTestBean) context.getBean("singleton");
 
 		// should not be a proxy
@@ -98,9 +98,9 @@ public class ClassPathBeanDefinitionScannerScopeIntegrationTests {
 	}
 
 	@Test
-	public void testSingletonScopeIgnoresProxyInterfaces() {
+	public void singletonScopeIgnoresProxyInterfaces() {
 		RequestContextHolder.setRequestAttributes(oldRequestAttributes);
-		ApplicationContext context = createContext(ScopedProxyMode.INTERFACES);
+		ApplicationContext context = createContext(INTERFACES);
 		ScopedTestBean bean = (ScopedTestBean) context.getBean("singleton");
 
 		// should not be a proxy
@@ -119,9 +119,9 @@ public class ClassPathBeanDefinitionScannerScopeIntegrationTests {
 	}
 
 	@Test
-	public void testSingletonScopeIgnoresProxyTargetClass() {
+	public void singletonScopeIgnoresProxyTargetClass() {
 		RequestContextHolder.setRequestAttributes(oldRequestAttributes);
-		ApplicationContext context = createContext(ScopedProxyMode.TARGET_CLASS);
+		ApplicationContext context = createContext(TARGET_CLASS);
 		ScopedTestBean bean = (ScopedTestBean) context.getBean("singleton");
 
 		// should not be a proxy
@@ -140,9 +140,9 @@ public class ClassPathBeanDefinitionScannerScopeIntegrationTests {
 	}
 
 	@Test
-	public void testRequestScopeWithNoProxy() {
+	public void requestScopeWithNoProxy() {
 		RequestContextHolder.setRequestAttributes(oldRequestAttributes);
-		ApplicationContext context = createContext(ScopedProxyMode.NO);
+		ApplicationContext context = createContext(NO);
 		ScopedTestBean bean = (ScopedTestBean) context.getBean("request");
 
 		// should not be a proxy
@@ -161,9 +161,9 @@ public class ClassPathBeanDefinitionScannerScopeIntegrationTests {
 	}
 
 	@Test
-	public void testRequestScopeWithProxiedInterfaces() {
+	public void requestScopeWithProxiedInterfaces() {
 		RequestContextHolder.setRequestAttributes(oldRequestAttributes);
-		ApplicationContext context = createContext(ScopedProxyMode.INTERFACES);
+		ApplicationContext context = createContext(INTERFACES);
 		IScopedTestBean bean = (IScopedTestBean) context.getBean("request");
 
 		// should be dynamic proxy, implementing both interfaces
@@ -182,9 +182,9 @@ public class ClassPathBeanDefinitionScannerScopeIntegrationTests {
 	}
 
 	@Test
-	public void testRequestScopeWithProxiedTargetClass() {
+	public void requestScopeWithProxiedTargetClass() {
 		RequestContextHolder.setRequestAttributes(oldRequestAttributes);
-		ApplicationContext context = createContext(ScopedProxyMode.TARGET_CLASS);
+		ApplicationContext context = createContext(TARGET_CLASS);
 		IScopedTestBean bean = (IScopedTestBean) context.getBean("request");
 
 		// should be a class-based proxy
@@ -203,9 +203,9 @@ public class ClassPathBeanDefinitionScannerScopeIntegrationTests {
 	}
 
 	@Test
-	public void testSessionScopeWithNoProxy() {
+	public void sessionScopeWithNoProxy() {
 		RequestContextHolder.setRequestAttributes(oldRequestAttributesWithSession);
-		ApplicationContext context = createContext(ScopedProxyMode.NO);
+		ApplicationContext context = createContext(NO);
 		ScopedTestBean bean = (ScopedTestBean) context.getBean("session");
 
 		// should not be a proxy
@@ -224,9 +224,9 @@ public class ClassPathBeanDefinitionScannerScopeIntegrationTests {
 	}
 
 	@Test
-	public void testSessionScopeWithProxiedInterfaces() {
+	public void sessionScopeWithProxiedInterfaces() {
 		RequestContextHolder.setRequestAttributes(oldRequestAttributesWithSession);
-		ApplicationContext context = createContext(ScopedProxyMode.INTERFACES);
+		ApplicationContext context = createContext(INTERFACES);
 		IScopedTestBean bean = (IScopedTestBean) context.getBean("session");
 
 		// should be dynamic proxy, implementing both interfaces
@@ -251,9 +251,9 @@ public class ClassPathBeanDefinitionScannerScopeIntegrationTests {
 	}
 
 	@Test
-	public void testSessionScopeWithProxiedTargetClass() {
+	public void sessionScopeWithProxiedTargetClass() {
 		RequestContextHolder.setRequestAttributes(oldRequestAttributesWithSession);
-		ApplicationContext context = createContext(ScopedProxyMode.TARGET_CLASS);
+		ApplicationContext context = createContext(TARGET_CLASS);
 		IScopedTestBean bean = (IScopedTestBean) context.getBean("session");
 
 		// should be a class-based proxy
@@ -283,12 +283,7 @@ public class ClassPathBeanDefinitionScannerScopeIntegrationTests {
 		GenericWebApplicationContext context = new GenericWebApplicationContext();
 		ClassPathBeanDefinitionScanner scanner = new ClassPathBeanDefinitionScanner(context);
 		scanner.setIncludeAnnotationConfig(false);
-		scanner.setBeanNameGenerator(new BeanNameGenerator() {
-			@Override
-			public String generateBeanName(BeanDefinition definition, BeanDefinitionRegistry registry) {
-				return definition.getScope();
-			}
-		});
+		scanner.setBeanNameGenerator((definition, registry) -> definition.getScope());
 		scanner.setScopedProxyMode(scopedProxyMode);
 
 		// Scan twice in order to find errors in the bean definition compatibility check.
@@ -300,7 +295,7 @@ public class ClassPathBeanDefinitionScannerScopeIntegrationTests {
 	}
 
 
- 	public static interface IScopedTestBean {
+ 	static interface IScopedTestBean {
 
  		String getName();
 
@@ -308,7 +303,7 @@ public class ClassPathBeanDefinitionScannerScopeIntegrationTests {
  	}
 
 
-	public static abstract class ScopedTestBean implements IScopedTestBean {
+	static abstract class ScopedTestBean implements IScopedTestBean {
 
 		private String name = DEFAULT_NAME;
 
@@ -321,23 +316,23 @@ public class ClassPathBeanDefinitionScannerScopeIntegrationTests {
 
 
 	@Component
-	public static class SingletonScopedTestBean extends ScopedTestBean {
+	static class SingletonScopedTestBean extends ScopedTestBean {
 	}
 
 
-	public static interface AnotherScopeTestInterface {
+	static interface AnotherScopeTestInterface {
 	}
 
 
 	@Component
-	@Scope("request")
-	public static class RequestScopedTestBean extends ScopedTestBean implements AnotherScopeTestInterface {
+	@RequestScope(proxyMode = DEFAULT)
+	static class RequestScopedTestBean extends ScopedTestBean implements AnotherScopeTestInterface {
 	}
 
 
 	@Component
-	@Scope("session")
-	public static class SessionScopedTestBean extends ScopedTestBean implements AnotherScopeTestInterface {
+	@SessionScope(proxyMode = DEFAULT)
+	static class SessionScopedTestBean extends ScopedTestBean implements AnotherScopeTestInterface {
 	}
 
 }