Polish CORS global configuration

This commit introduces the following changes:
 - configureCors(CorsConfigurer configurer) is renamed to
   addCorsMappings(CorsRegistry registry)
 - enableCors(String... pathPatterns) is renamed to
   addMapping(String pathPattern)
 - <cors /> element must have at least one <mapping /> child
   element in order to be consistent with XML based configuration
   and have more explicit configuration

Issues: SPR-12933, SPR-13046

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/CorsRegistration.java

@@ -34,12 +34,12 @@ import org.springframework.web.cors.CorsConfiguration;
  */
 public class CorsRegistration {
 
-	private final String[] pathPatterns;
+	private final String pathPattern;
 
 	private final CorsConfiguration config;
 
-	public CorsRegistration(String... pathPatterns) {
-		this.pathPatterns = (pathPatterns.length == 0 ? new String[]{ "/**" } : pathPatterns);
+	public CorsRegistration(String pathPattern) {
+		this.pathPattern = pathPattern;
 		// Same default values than @CrossOrigin annotation + allows simple methods
 		this.config = new CorsConfiguration();
 		this.config.addAllowedOrigin("*");
@@ -81,8 +81,8 @@ public class CorsRegistration {
 		return this;
 	}
 
-	protected String[] getPathPatterns() {
-		return this.pathPatterns;
+	protected String getPathPattern() {
+		return this.pathPattern;
 	}
 
 	protected CorsConfiguration getCorsConfiguration() {

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/CorsRegistry.java

@@ -24,25 +24,27 @@ import java.util.Map;
 import org.springframework.web.cors.CorsConfiguration;
 
 /**
- * Assist with the registration of {@link CorsConfiguration} mapped to one or more path patterns.
+ * Assist with the registration of {@link CorsConfiguration} mapped on a path pattern.
  * @author Sebastien Deleuze
  *
  * @since 4.2
  * @see CorsRegistration
  */
-public class CorsConfigurer {
+public class CorsRegistry {
 
 	private final List<CorsRegistration> registrations = new ArrayList<CorsRegistration>();
 
 
 	/**
-	 * Enable cross origin requests on the specified path patterns. If no path pattern is specified,
-	 * cross-origin request handling is mapped on "/**" .
+	 * Enable cross origin requests processing on the specified path pattern.
+	 * Exact path mapping URIs (such as "/admin") are supported as well as Ant-stype path
+	 * patterns (such as /admin/**).
 	 *
-	 * <p>By default, all origins, all headers and credentials are allowed. Max age is set to 30 minutes.</p>
+	 * <p>By default, all origins, all headers, credentials and GET, HEAD, POST methods are allowed.
+	 * Max age is set to 30 minutes.</p>
 	 */
-	public CorsRegistration enableCors(String... pathPatterns) {
-		CorsRegistration registration = new CorsRegistration(pathPatterns);
+	public CorsRegistration addMapping(String pathPattern) {
+		CorsRegistration registration = new CorsRegistration(pathPattern);
 		this.registrations.add(registration);
 		return registration;
 	}
@@ -50,9 +52,7 @@ public class CorsConfigurer {
 	protected Map<String, CorsConfiguration> getCorsConfigurations() {
 		Map<String, CorsConfiguration> configs = new LinkedHashMap<String, CorsConfiguration>(this.registrations.size());
 		for (CorsRegistration registration : this.registrations) {
-			for (String pathPattern : registration.getPathPatterns()) {
-				configs.put(pathPattern, registration.getCorsConfiguration());
-			}
+			configs.put(registration.getPathPattern(), registration.getCorsConfiguration());
 		}
 		return configs;
 	}

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/DelegatingWebMvcConfiguration.java

@@ -133,8 +133,8 @@ public class DelegatingWebMvcConfiguration extends WebMvcConfigurationSupport {
 	}
 
 	@Override
-	protected void configureCors(CorsConfigurer configurer) {
-		this.configurers.configureCors(configurer);
+	protected void addCorsMappings(CorsRegistry registry) {
+		this.configurers.addCorsMappings(registry);
 	}
 
 }

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurationSupport.java

@@ -875,19 +875,19 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 	 */
 	protected final Map<String, CorsConfiguration> getCorsConfigurations() {
 		if (this.corsConfigurations == null) {
-			CorsConfigurer registry = new CorsConfigurer();
-			configureCors(registry);
+			CorsRegistry registry = new CorsRegistry();
+			addCorsMappings(registry);
 			this.corsConfigurations = registry.getCorsConfigurations();
 		}
 		return this.corsConfigurations;
 	}
 
 	/**
-	 * Override this method to configure cross-origin requests handling.
+	 * Override this method to configure cross origin requests processing.
 	 * @since 4.2
-	 * @see CorsConfigurer
+	 * @see CorsRegistry
 	 */
-	protected void configureCors(CorsConfigurer configurer) {
+	protected void addCorsMappings(CorsRegistry registry) {
 	}
 
 

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurer.java

@@ -183,9 +183,9 @@ public interface WebMvcConfigurer {
 	void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer);
 
 	/**
-	 * Configure cross-origin requests handling.
+	 * Configure cross origin requests processing.
 	 * @since 4.2
 	 */
-	void configureCors(CorsConfigurer configurer);
+	void addCorsMappings(CorsRegistry registry);
 
 }

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurerAdapter.java

@@ -170,7 +170,7 @@ public abstract class WebMvcConfigurerAdapter implements WebMvcConfigurer {
 	 * <p>This implementation is empty.
 	 */
 	@Override
-	public void configureCors(CorsConfigurer configurer) {
+	public void addCorsMappings(CorsRegistry registry) {
 	}
 
 }

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurerComposite.java

@@ -154,9 +154,9 @@ class WebMvcConfigurerComposite implements WebMvcConfigurer {
 	}
 
 	@Override
-	public void configureCors(CorsConfigurer configurer) {
+	public void addCorsMappings(CorsRegistry registry) {
 		for (WebMvcConfigurer delegate : this.delegates) {
-			delegate.configureCors(configurer);
+			delegate.addCorsMappings(registry);
 		}
 	}
 

spring-webmvc/src/main/resources/org/springframework/web/servlet/config/spring-mvc-4.2.xsd

@@ -1237,17 +1237,15 @@
 	<xsd:element name="cors">
 		<xsd:annotation>
 			<xsd:documentation><![CDATA[
-	Configure cross origin requests handling.
-	By default, all origins, GET HEAD POST methods, all headers and credentials
-	are allowed and max age is set to 30 minutes.
+	Configure cross origin requests processing.
 			]]></xsd:documentation>
 		</xsd:annotation>
 		<xsd:complexType>
 			<xsd:sequence>
-				<xsd:element name="mapping" minOccurs="0" maxOccurs="unbounded">
+				<xsd:element name="mapping" minOccurs="1" maxOccurs="unbounded">
 					<xsd:annotation>
 						<xsd:documentation><![CDATA[
-				Enable cross origin requests handling on the specified path patterns.
+				Enable cross origin requests processing on the specified path pattern.
 				By default, all origins, GET HEAD POST methods, all headers and credentials
 				are allowed and max age is set to 30 minutes.
 						]]></xsd:documentation>

spring-webmvc/src/test/java/org/springframework/web/servlet/config/annotation/CorsRegistryTests.java

@@ -27,50 +27,37 @@ import org.junit.Test;
 import org.springframework.web.cors.CorsConfiguration;
 
 /**
- * Test fixture with a {@link CorsConfigurer}.
+ * Test fixture with a {@link CorsRegistry}.
  *
  * @author Sebastien Deleuze
  */
-public class CorsConfigurerTests {
+public class CorsRegistryTests {
 
-	private CorsConfigurer configurer;
+	private CorsRegistry registry;
 
 	@Before
 	public void setUp() {
-		this.configurer = new CorsConfigurer();
+		this.registry = new CorsRegistry();
 	}
 
 	@Test
-	public void noCorsConfigured() {
-		assertTrue(this.configurer.getCorsConfigurations().isEmpty());
+	public void noMapping() {
+		assertTrue(this.registry.getCorsConfigurations().isEmpty());
 	}
 
 	@Test
-	public void multipleCorsConfigured() {
-		this.configurer.enableCors("/foo");
-		this.configurer.enableCors("/bar");
-		assertEquals(2, this.configurer.getCorsConfigurations().size());
+	public void multipleMappings() {
+		this.registry.addMapping("/foo");
+		this.registry.addMapping("/bar");
+		assertEquals(2, this.registry.getCorsConfigurations().size());
 	}
 
 	@Test
-	public void defaultCorsRegistration() {
-		this.configurer.enableCors();
-		Map<String, CorsConfiguration> configs = this.configurer.getCorsConfigurations();
-		assertEquals(1, configs.size());
-		CorsConfiguration config = configs.get("/**");
-		assertEquals(Arrays.asList("*"), config.getAllowedOrigins());
-		assertEquals(Arrays.asList("GET", "HEAD", "POST"), config.getAllowedMethods());
-		assertEquals(Arrays.asList("*"), config.getAllowedHeaders());
-		assertEquals(true, config.getAllowCredentials());
-		assertEquals(Long.valueOf(1800), config.getMaxAge());
-	}
-
-	@Test
-	public void customizedCorsRegistration() {
-		this.configurer.enableCors("/foo").allowedOrigins("http://domain2.com", "http://domain2.com")
+	public void customizedMapping() {
+		this.registry.addMapping("/foo").allowedOrigins("http://domain2.com", "http://domain2.com")
 				.allowedMethods("DELETE").allowCredentials(false).allowedHeaders("header1", "header2")
 				.exposedHeaders("header3", "header4").maxAge(3600);
-		Map<String, CorsConfiguration> configs = this.configurer.getCorsConfigurations();
+		Map<String, CorsConfiguration> configs = this.registry.getCorsConfigurations();
 		assertEquals(1, configs.size());
 		CorsConfiguration config = configs.get("/foo");
 		assertEquals(Arrays.asList("http://domain2.com", "http://domain2.com"), config.getAllowedOrigins());

spring-webmvc/src/test/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurationSupportExtensionTests.java

@@ -404,8 +404,8 @@ public class WebMvcConfigurationSupportExtensionTests {
 		}
 
 		@Override
-		public void configureCors(CorsConfigurer registry) {
-			registry.enableCors("/resources/**");
+		public void addCorsMappings(CorsRegistry registry) {
+			registry.addMapping("/resources/**");
 		}
 	
 	}

spring-webmvc/src/test/resources/org/springframework/web/servlet/config/mvc-config-cors-minimal.xml

@@ -6,7 +6,9 @@
 		http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">
 
 	<!-- <mvc:cors /> element before <mvc:annotation-driven /> one -->
-	<mvc:cors />
+	<mvc:cors>
+		<mvc:mapping path="/**" />
+	</mvc:cors>
 
 	<mvc:annotation-driven />