SWF-8214 javadoc updates

git-svn-id: https://src.springframework.org/svn/spring-framework/trunk@4218 50f2f4bb-b051-0410-bef5-90022cba6387

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/handler/AbstractHandlerMethodMapping.java

@@ -36,7 +36,21 @@ import org.springframework.web.method.HandlerMethodSelector;
 
 /**
  * Abstract base class for {@link org.springframework.web.servlet.HandlerMapping HandlerMapping} implementations that
- * support {@link HandlerMethod}s.
+ * support mapping requests to {@link HandlerMethod}s rather than to handlers.
+ * 
+ * <p>Each {@link HandlerMethod} is registered with a unique key. Subclasses define the key type and how to create it
+ * for a given handler method. Keys represent conditions for matching a handler method to a request. 
+ *
+ * <p>Subclasses must also define how to create a key for an incoming request. The resulting key is used to perform 
+ * a {@link HandlerMethod} lookup possibly resulting in a direct match. However, when a map lookup is insufficient, 
+ * the keys of all handler methods are iterated and subclasses are allowed to make an exhaustive check of key 
+ * conditions against the request.
+ * 
+ * <p>Since there can be more than one matching key for a request, subclasses must define a comparator for sorting
+ * the keys of matching handler methods in order to find the most specific match.
+ *
+ * @param <T> A unique key for the registration of mapped {@link HandlerMethod}s representing the conditions to
+ * match a handler method to a request.
  * 
  * @author Arjen Poutsma
  * @author Rossen Stoyanchev
@@ -80,6 +94,9 @@ public abstract class AbstractHandlerMethodMapping<T> extends AbstractHandlerMap
 	 */
 	protected abstract boolean isHandler(String beanName);
 
+	/**
+	 * Detect and register handler methods for the specified handler.
+	 */
 	private void detectHandlerMethods(final String handlerName) {
 		Class<?> handlerType = getApplicationContext().getType(handlerName);
 

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestKey.java

@@ -33,10 +33,18 @@ import org.springframework.web.servlet.mvc.method.condition.RequestConditionFact
 import org.springframework.web.util.UrlPathHelper;
 
 /**
- * TODO
+ * Contains a set of conditions to match to a given request such as URL patterns, HTTP methods, request 
+ * parameters and headers. 
+ * 
+ * <p>A {@link RequestKey} can be combined with another {@link RequestKey} resulting in a new {@link RequestKey}
+ * with conditions from both (see {@link #combine(RequestKey, PathMatcher)}).
+ * 
+ * <p>A {@link RequestKey} can be matched to a request resulting in a new {@link RequestKey} with the subset of
+ * conditions relevant to the request (see {@link #getMatchingKey(HttpServletRequest, PathMatcher, UrlPathHelper)}).
  * 
  * @author Arjen Poutsma
  * @author Rossen Stoyanchev
+ * @since 3.1
  */
 public final class RequestKey {
 
@@ -52,14 +60,19 @@ public final class RequestKey {
 
 	private int hash;
 
+	/**
+	 * Creates a new {@code RequestKey} instance with the given URL patterns and HTTP methods.
+	 * 
+	 * <p>Package protected for testing purposes.
+	 */
 	RequestKey(Collection<String> patterns, Collection<RequestMethod> methods) {
 		this(patterns, methods, null, null, null);
 	}
 
 	/**
-	 * Creates a new {@code RequestKey} instance with the given parameters.
+	 * Creates a new {@code RequestKey} instance with a full set of conditions.
 	 * 
-	 * <p/>Package protected for testing purposes.
+	 * <p>Package protected for testing purposes.
 	 */
 	RequestKey(Collection<String> patterns,
 			   Collection<RequestMethod> methods,
@@ -152,12 +165,22 @@ public final class RequestKey {
 	}
 
 	/**
-	 * Combines this {@code RequestKey} with another. The typical use case for this is combining type
+	 * Combines this {@code RequestKey} with another as follows: 
-	 * and method-level {@link RequestMapping @RequestMapping} annotations.
+	 * <ul>
-	 *
+	 * <li>URL patterns:
-	 * @param methodKey the method-level RequestKey
+	 * 	<ul>
+	 * 	  <li>If both keys have path patterns combine them according to the rules of the given {@link PathMatcher}.
+	 * 	  <li>If either key contains path patterns but not both use only what is available.
+	 * 	  <li>If neither key contains path patterns use "/".
+	 * 	</ul>
+	 * <li>HTTP methods are combined as union of all HTTP methods listed in both keys.
+	 * <li>Request parameter are combined into a logical AND.
+	 * <li>Request header are combined into a logical AND.
+	 * <li>Consumes .. TODO
+	 * </ul>
+	 * @param methodKey the key to combine with
 	 * @param pathMatcher to {@linkplain PathMatcher#combine(String, String) combine} the patterns
-	 * @return the combined request key
+	 * @return a new request key containing conditions from both keys
 	 */
 	public RequestKey combine(RequestKey methodKey, PathMatcher pathMatcher) {
 		Set<String> patterns = combinePatterns(this.patterns, methodKey.patterns, pathMatcher);
@@ -199,15 +222,18 @@ public final class RequestKey {
 	}
 
 	/**
-	 * Returns a new {@code RequestKey} that contains all matching attributes of this key, given the {@link
+	 * Returns a new {@code RequestKey} that contains all conditions of this key that are relevant to the request.
-	 * HttpServletRequest}. Matching patterns in the returned RequestKey are sorted according to {@link
+	 * <ul>
-	 * PathMatcher#getPatternComparator(String)} with the best matching pattern at the top.
+	 * <li>The list of URL path patterns is trimmed to contain the patterns that match the URL with matching patterns 
-	 *
+	 * sorted via {@link PathMatcher#getPatternComparator(String)}. 
-	 * @param request the servlet request
+	 * <li>The list of HTTP methods is trimmed to contain only the method of the request. 
-	 * @param pathMatcher to {@linkplain PathMatcher#match(String, String) match} patterns
+	 * <li>Request parameter and request header conditions are included in full. 
-	 * @param urlPathHelper to create the {@linkplain UrlPathHelper#getLookupPathForRequest(HttpServletRequest) lookup
+	 * <li>The list of consumes conditions is trimmed and sorted to match the request "Content-Type" header.
-	 * path}
+	 * </ul>   
-	 * @return a new request key that contains all matching attributes
+	 * @param request the current request
+	 * @param pathMatcher to check for matching patterns
+	 * @param urlPathHelper to derive the lookup path for the request
+	 * @return a new request key that contains all matching attributes, or {@code null} if not all conditions match
 	 */
 	public RequestKey getMatchingKey(HttpServletRequest request, PathMatcher pathMatcher, UrlPathHelper urlPathHelper) {
 		if (!checkMethod(request) || !paramsCondition.match(request) || !headersCondition.match(request) ||
@@ -217,7 +243,7 @@ public final class RequestKey {
 		else {
 			List<String> matchingPatterns = getMatchingPatterns(request, pathMatcher, urlPathHelper);
 			if (!matchingPatterns.isEmpty()) {
-				Set<RequestMethod> matchingMethods = getMatchingMethods(request);
+				Set<RequestMethod> matchingMethods = getMatchingMethod(request);
 				return new RequestKey(matchingPatterns, matchingMethods, this.paramsCondition, this.headersCondition,
 						this.consumesCondition);
 			}
@@ -245,7 +271,7 @@ public final class RequestKey {
 		return matchingPatterns;
 	}
 
-	private Set<RequestMethod> getMatchingMethods(HttpServletRequest request) {
+	private Set<RequestMethod> getMatchingMethod(HttpServletRequest request) {
 		if (this.methods.isEmpty()) {
 			return this.methods;
 		}

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerMethodMapping.java

@@ -23,6 +23,7 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+
 import javax.servlet.http.HttpServletRequest;
 
 import org.springframework.core.annotation.AnnotationUtils;
@@ -44,7 +45,22 @@ import org.springframework.web.servlet.handler.MappedInterceptors;
 import org.springframework.web.util.UrlPathHelper;
 
 /**
- * TODO
+ * An {@link AbstractHandlerMethodMapping} variant that uses {@link RequestKey}s for the registration and the lookup 
+ * of {@link HandlerMethod}s.
+ * 
+ * <p>A {@link RequestKey} for an incoming request contains the URL and the HTTP method of the request. 
+ * A {@link RequestKey} for a handler method contains all conditions found in the method @{@link RequestMapping} 
+ * annotation combined with all conditions found in the type @{@link RequestMapping} annotation, if present. 
+ * 
+ * <p>An incoming request matches to a handler method directly when a @{@link RequestMapping} annotation contains 
+ * a single, non-pattern URL and a single HTTP method. When a {@link RequestKey} contains additional conditions 
+ * (e.g. more URL patterns, request parameters, headers, etc) those conditions must be checked against the 
+ * request rather than against the key that represents it. This results in the creation of a new handler method 
+ * {@link RequestKey} with the subset of conditions relevant to the current request (see 
+ * {@link RequestKey#getMatchingKey(HttpServletRequest, PathMatcher, UrlPathHelper)}).
+ * Such keys can then be compared against each other, in the context of the current request, making it possible 
+ * to select to the best matching {@link RequestKey} in case of multiple matches and also the best matching 
+ * pattern within the selected key.   
  * 
  * @author Arjen Poutsma
  * @author Rossen Stoyanchev
@@ -168,6 +184,18 @@ public class RequestMappingHandlerMethodMapping extends AbstractHandlerMethodMap
 		}
 	}
 
+	/**
+	 * Returns a new {@link RequestKey} with attributes matching to the current request or {@code null}.
+	 * @see RequestKey#getMatchingKey(HttpServletRequest, PathMatcher, UrlPathHelper)
+	 */
+	@Override
+	protected RequestKey getMatchingKey(RequestKey key, HttpServletRequest request) {
+		return key.getMatchingKey(request, pathMatcher, urlPathHelper);
+	}
+
+	/**
+	 * Returns a {@link Comparator} that can be used to sort and select the best matching {@link RequestKey}.
+	 */
 	@Override
 	protected Comparator<RequestKey> getKeyComparator(HttpServletRequest request) {
 		return new RequestKeyComparator(request);
@@ -181,24 +209,10 @@ public class RequestMappingHandlerMethodMapping extends AbstractHandlerMethodMap
 		request.setAttribute(HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE, uriTemplateVariables);
 	}
 
-	@Override
+	/**
-	protected RequestKey getMatchingKey(RequestKey key, HttpServletRequest request) {
+	 * Iterates all {@link RequestKey}s looking for keys that match by URL but not by HTTP method.
-		return key.getMatchingKey(request, pathMatcher, urlPathHelper);
+	 * @exception HttpRequestMethodNotSupportedException if there are matches by URL but not by HTTP method
-	}
+	 */
-
-	@Override
-	protected HandlerExecutionChain getHandlerExecutionChain(Object handler, HttpServletRequest request) {
-		HandlerExecutionChain chain = super.getHandlerExecutionChain(handler, request);
-		if (this.mappedInterceptors != null) {
-			String lookupPath = urlPathHelper.getLookupPathForRequest(request);
-			HandlerInterceptor[] handlerInterceptors = mappedInterceptors.getInterceptors(lookupPath, pathMatcher);
-			if (handlerInterceptors.length > 0) {
-				chain.addInterceptors(handlerInterceptors);
-			}
-		}
-		return chain;
-	}
-
 	@Override
 	protected HandlerMethod handleNoMatch(Set<RequestKey> requestKeys, HttpServletRequest request)
 			throws HttpRequestMethodNotSupportedException {
@@ -223,13 +237,29 @@ public class RequestMappingHandlerMethodMapping extends AbstractHandlerMethodMap
 	}
 
 	/**
-	 * A comparator for RequestKey types. Effective comparison can only be done in the context of a specific request. For
+	 * Adds mapped interceptors to the handler execution chain.
-	 * example not all configured patterns may apply to the current request. Therefore an HttpServletRequest is required as
+	 */
-	 * input.
+	@Override
+	protected HandlerExecutionChain getHandlerExecutionChain(Object handler, HttpServletRequest request) {
+		HandlerExecutionChain chain = super.getHandlerExecutionChain(handler, request);
+		if (this.mappedInterceptors != null) {
+			String lookupPath = urlPathHelper.getLookupPathForRequest(request);
+			HandlerInterceptor[] handlerInterceptors = mappedInterceptors.getInterceptors(lookupPath, pathMatcher);
+			if (handlerInterceptors.length > 0) {
+				chain.addInterceptors(handlerInterceptors);
+			}
+		}
+		return chain;
+	}
+
+	/**
+	 * A comparator for {@link RequestKey}s. Effective comparison can only be done in the context of a 
+	 * specific request. For example not all {@link RequestKey} patterns may apply to the current request. 
+	 * Therefore an HttpServletRequest is required as input.
 	 *
-	 * Furthermore, the following assumptions are made about the input RequestKeys: <ul> <li>Each RequestKey has been fully
+	 * <p>Furthermore, the following assumptions are made about the input RequestKeys: 
-	 * matched to the request <li>The RequestKey contains matched patterns only <li>Patterns are ordered with the best
+	 * <ul><li>Each RequestKey has been fully matched to the request <li>The RequestKey contains matched 
-	 * matching pattern at the top </ul>
+	 * patterns only <li>Patterns are ordered with the best matching pattern at the top </ul>
 	 *
 	 * @see RequestMappingHandlerMethodMapping#getMatchingKey(RequestKey, HttpServletRequest)
 	 */