Add CompositeRequestCondition

The new type makes it easier providing multiple custom request mapping
conditions via setters on RequestMappingHandlerMapping.

Issue: SPR-9350

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/condition/CompositeRequestCondition.java

@@ -0,0 +1,181 @@
+/*
+ * Copyright 2002-2012 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.servlet.mvc.condition;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.springframework.util.Assert;
+import org.springframework.util.ObjectUtils;
+
+import edu.emory.mathcs.backport.java.util.Collections;
+
+/**
+ * Implements the {@link RequestCondition} contract by delegating to multiple
+ * {@code RequestCondition} types and using a logical conjunction (' && ') to
+ * ensure all conditions match a given request.
+ *
+ * <p>When {@code CompositeRequestCondition} instances are combined or compared
+ * they are expected to (a) contain the same number of conditions and (b) that
+ * conditions in the respective index are of the same type. It is acceptable to
+ * provide {@code null} conditions or no conditions at all to the constructor.
+ *
+ * @author Rossen Stoyanchev
+ * @since 3.2
+ */
+public class CompositeRequestCondition extends AbstractRequestCondition<CompositeRequestCondition> {
+
+	private final RequestConditionHolder[] requestConditions;
+
+	/**
+	 * Create an instance with 0 or more {@code RequestCondition} types. It is
+	 * important to create {@code CompositeRequestCondition} instances with the
+	 * same number of conditions so they may be compared and combined.
+	 * It is acceptable to provide {@code null} conditions.
+	 */
+	public CompositeRequestCondition(RequestCondition<?>... requestConditions) {
+		this.requestConditions = wrap(requestConditions);
+	}
+
+	private RequestConditionHolder[] wrap(RequestCondition<?>... rawConditions) {
+		RequestConditionHolder[] wrappedConditions = new RequestConditionHolder[rawConditions.length];
+		for (int i = 0; i < rawConditions.length; i++) {
+			wrappedConditions[i] = new RequestConditionHolder(rawConditions[i]);
+		}
+		return wrappedConditions;
+	}
+
+	private CompositeRequestCondition(RequestConditionHolder[] requestConditions) {
+		this.requestConditions = requestConditions;
+	}
+
+	/**
+	 * Whether this instance contains 0 conditions or not.
+	 */
+	public boolean isEmpty() {
+		return ObjectUtils.isEmpty(this.requestConditions);
+	}
+
+	/**
+	 * Return the underlying conditions, possibly empty but never {@code null}.
+	 */
+	public List<RequestCondition<?>> getConditions() {
+		return unwrap();
+	}
+
+	private List<RequestCondition<?>> unwrap() {
+		List<RequestCondition<?>> result = new ArrayList<RequestCondition<?>>();
+		for (RequestConditionHolder holder : this.requestConditions) {
+			result.add(holder.getCondition());
+		}
+		return result;
+	}
+
+	@Override
+	protected Collection<?> getContent() {
+		return (isEmpty()) ? Collections.emptyList() : getConditions();
+	}
+
+	@Override
+	protected String getToStringInfix() {
+		return " && ";
+	}
+
+	private int getLength() {
+		return this.requestConditions.length;
+	}
+
+	/**
+	 * If one instance is empty, return the other.
+	 * If both instances have conditions, combine the individual conditions
+	 * after ensuring they are of the same type and number.
+	 */
+	public CompositeRequestCondition combine(CompositeRequestCondition other) {
+		if (isEmpty() && other.isEmpty()) {
+			return this;
+		}
+		else if (other.isEmpty()) {
+			return this;
+		}
+		else if (isEmpty()) {
+			return other;
+		}
+		else {
+			assertNumberOfConditions(other);
+			RequestConditionHolder[] combinedConditions = new RequestConditionHolder[getLength()];
+			for (int i = 0; i < getLength(); i++) {
+				combinedConditions[i] = this.requestConditions[i].combine(other.requestConditions[i]);
+			}
+			return new CompositeRequestCondition(combinedConditions);
+		}
+	}
+
+	private void assertNumberOfConditions(CompositeRequestCondition other) {
+		Assert.isTrue(getLength() == other.getLength(),
+				"Cannot combine CompositeRequestConditions with a different number of conditions. "
+					+ this.requestConditions + " and  " + other.requestConditions);
+	}
+
+	/**
+	 * Delegate to <em>all</em> contained conditions to match the request and return the
+	 * resulting "matching" condition instances.
+	 * <p>An empty {@code CompositeRequestCondition} matches to all requests.
+	 */
+	public CompositeRequestCondition getMatchingCondition(HttpServletRequest request) {
+		if (isEmpty()) {
+			return this;
+		}
+		RequestConditionHolder[] matchingConditions = new RequestConditionHolder[getLength()];
+		for (int i = 0; i < getLength(); i++) {
+			matchingConditions[i] = this.requestConditions[i].getMatchingCondition(request);
+			if (matchingConditions[i] == null) {
+				return null;
+			}
+		}
+		return new CompositeRequestCondition(matchingConditions);
+	}
+
+	/**
+	 * If one instance is empty, the other "wins". If both instances have
+	 * conditions, compare them in the order in which they were provided.
+	 */
+	public int compareTo(CompositeRequestCondition other, HttpServletRequest request) {
+		if (isEmpty() && other.isEmpty()) {
+			return 0;
+		}
+		else if (isEmpty()) {
+			return 1;
+		}
+		else if (other.isEmpty()) {
+			return -1;
+		}
+		else {
+			assertNumberOfConditions(other);
+			for (int i = 0; i < getLength(); i++) {
+				int result = this.requestConditions[i].compareTo(other.requestConditions[i], request);
+				if (result != 0) {
+					return result;
+				}
+			}
+			return 0;
+		}
+	}
+
+}

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/condition/RequestConditionHolder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -23,40 +23,42 @@ import javax.servlet.http.HttpServletRequest;
 
 
 /**
- * A holder for a {@link RequestCondition} useful when the type of the held
+ * A holder for a {@link RequestCondition} useful when the type of the request
- * request condition is not known ahead of time - e.g. custom condition.
+ * condition is not known ahead of time, e.g. custom condition. Since this
+ * class is also an implementation of {@code RequestCondition}, effectively it
+ * decorates the held request condition and allows it to be combined and compared
+ * with other request conditions in a type and null safe way.
  *
- * <p>An implementation of {@code RequestCondition} itself, a
+ * <p>When two {@code RequestConditionHolder} instances are combined or compared
- * {@code RequestConditionHolder} decorates the held request condition allowing
+ * with each other, it is expected the conditions they hold are of the same type.
- * it to be combined and compared with other custom request conditions while
+ * If they are not, a {@link ClassCastException} is raised.
- * ensuring type and null safety.
  *
  * @author Rossen Stoyanchev
  * @since 3.1
  */
 public final class RequestConditionHolder extends AbstractRequestCondition<RequestConditionHolder> {
 
-	@SuppressWarnings("rawtypes")
+	private final RequestCondition<Object> condition;
-	private final RequestCondition condition;
 
 	/**
 	 * Create a new holder to wrap the given request condition.
 	 * @param requestCondition the condition to hold, may be {@code null}
 	 */
+	@SuppressWarnings("unchecked")
 	public RequestConditionHolder(RequestCondition<?> requestCondition) {
-		this.condition = requestCondition;
+		this.condition = (RequestCondition<Object>) requestCondition;
 	}
 
 	/**
 	 * Return the held request condition, or {@code null} if not holding one.
 	 */
 	public RequestCondition<?> getCondition() {
-		return condition;
+		return this.condition;
 	}
 
 	@Override
 	protected Collection<?> getContent() {
-		return condition != null ? Collections.singleton(condition) : Collections.emptyList();
+		return this.condition != null ? Collections.singleton(this.condition) : Collections.emptyList();
 	}
 
 	@Override
@@ -69,20 +71,19 @@ public final class RequestConditionHolder extends AbstractRequestCondition<Reque
 	 * instances after making sure the conditions are of the same type.
 	 * Or if one holder is empty, the other holder is returned.
 	 */
-	@SuppressWarnings("unchecked")
 	public RequestConditionHolder combine(RequestConditionHolder other) {
-		if (condition == null && other.condition == null) {
+		if (this.condition == null && other.condition == null) {
 			return this;
 		}
-		else if (condition == null) {
+		else if (this.condition == null) {
 			return other;
 		}
 		else if (other.condition == null) {
 			return this;
 		}
 		else {
-			assertIsCompatible(other);
+			assertEqualConditionTypes(other);
-			RequestCondition<?> combined = (RequestCondition<?>) condition.combine(other.condition);
+			RequestCondition<?> combined = (RequestCondition<?>) this.condition.combine(other.condition);
 			return new RequestConditionHolder(combined);
 		}
 	}
@@ -90,8 +91,8 @@ public final class RequestConditionHolder extends AbstractRequestCondition<Reque
 	/**
 	 * Ensure the held request conditions are of the same type.
 	 */
-	private void assertIsCompatible(RequestConditionHolder other) {
+	private void assertEqualConditionTypes(RequestConditionHolder other) {
-		Class<?> clazz = condition.getClass();
+		Class<?> clazz = this.condition.getClass();
 		Class<?> otherClazz = other.condition.getClass();
 		if (!clazz.equals(otherClazz)) {
 			throw new ClassCastException("Incompatible request conditions: " + clazz + " and " + otherClazz);
@@ -104,10 +105,10 @@ public final class RequestConditionHolder extends AbstractRequestCondition<Reque
 	 * holder, return the same holder instance.
 	 */
 	public RequestConditionHolder getMatchingCondition(HttpServletRequest request) {
-		if (condition == null) {
+		if (this.condition == null) {
 			return this;
 		}
-		RequestCondition<?> match = (RequestCondition<?>) condition.getMatchingCondition(request);
+		RequestCondition<?> match = (RequestCondition<?>) this.condition.getMatchingCondition(request);
 		return (match != null) ? new RequestConditionHolder(match) : null;
 	}
 
@@ -116,20 +117,19 @@ public final class RequestConditionHolder extends AbstractRequestCondition<Reque
 	 * instances after making sure the conditions are of the same type.
 	 * Or if one holder is empty, the other holder is preferred.
 	 */
-	@SuppressWarnings("unchecked")
 	public int compareTo(RequestConditionHolder other, HttpServletRequest request) {
-		if (condition == null && other.condition == null) {
+		if (this.condition == null && other.condition == null) {
 			return 0;
 		}
-		else if (condition == null) {
+		else if (this.condition == null) {
 			return 1;
 		}
 		else if (other.condition == null) {
 			return -1;
 		}
 		else {
-			assertIsCompatible(other);
+			assertEqualConditionTypes(other);
-			return condition.compareTo(other.condition, request);
+			return this.condition.compareTo(other.condition, request);
 		}
 	}
 

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerMapping.java

@@ -21,6 +21,8 @@ import java.lang.reflect.Method;
 import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.servlet.mvc.condition.AbstractRequestCondition;
+import org.springframework.web.servlet.mvc.condition.CompositeRequestCondition;
 import org.springframework.web.servlet.mvc.condition.ConsumesRequestCondition;
 import org.springframework.web.servlet.mvc.condition.HeadersRequestCondition;
 import org.springframework.web.servlet.mvc.condition.ParamsRequestCondition;
@@ -113,23 +115,16 @@ public class RequestMappingHandlerMapping extends RequestMappingInfoHandlerMappi
 		return info;
 	}
 
-	/**
-	 * Provide a custom method-level request condition.
-	 * The custom {@link RequestCondition} can be of any type so long as the
-	 * same condition type is returned from all calls to this method in order
-	 * to ensure custom request conditions can be combined and compared.
-	 * @param method the handler method for which to create the condition
-	 * @return the condition, or {@code null}
-	 */
-	protected RequestCondition<?> getCustomMethodCondition(Method method) {
-		return null;
-	}
-
 	/**
 	 * Provide a custom type-level request condition.
 	 * The custom {@link RequestCondition} can be of any type so long as the
 	 * same condition type is returned from all calls to this method in order
 	 * to ensure custom request conditions can be combined and compared.
+	 *
+	 * <p>Consider extending {@link AbstractRequestCondition} for custom
+	 * condition types and using {@link CompositeRequestCondition} to provide
+	 * multiple custom conditions.
+	 *
 	 * @param handlerType the handler type for which to create the condition
 	 * @return the condition, or {@code null}
 	 */
@@ -137,6 +132,23 @@ public class RequestMappingHandlerMapping extends RequestMappingInfoHandlerMappi
 		return null;
 	}
 
+	/**
+	 * Provide a custom method-level request condition.
+	 * The custom {@link RequestCondition} can be of any type so long as the
+	 * same condition type is returned from all calls to this method in order
+	 * to ensure custom request conditions can be combined and compared.
+	 *
+	 * <p>Consider extending {@link AbstractRequestCondition} for custom
+	 * condition types and using {@link CompositeRequestCondition} to provide
+	 * multiple custom conditions.
+	 *
+	 * @param method the handler method for which to create the condition
+	 * @return the condition, or {@code null}
+	 */
+	protected RequestCondition<?> getCustomMethodCondition(Method method) {
+		return null;
+	}
+
 	/**
 	 * Created a RequestMappingInfo from a RequestMapping annotation.
 	 */

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/condition/CompositeRequestConditionTests.java

@@ -0,0 +1,141 @@
+/*
+ * Copyright 2002-2011 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.servlet.mvc.condition;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.mock.web.MockHttpServletRequest;
+import org.springframework.web.bind.annotation.RequestMethod;
+
+/**
+ * A test fixture for {@link CompositeRequestCondition} tests.
+ *
+ * @author Rossen Stoyanchev
+ */
+public class CompositeRequestConditionTests {
+
+	private ParamsRequestCondition param1;
+	private ParamsRequestCondition param2;
+	private ParamsRequestCondition param3;
+
+	private HeadersRequestCondition header1;
+	private HeadersRequestCondition header2;
+	private HeadersRequestCondition header3;
+
+	@Before
+	public void setup() {
+		this.param1 = new ParamsRequestCondition("param1");
+		this.param2 = new ParamsRequestCondition("param2");
+		this.param3 = this.param1.combine(this.param2);
+
+		this.header1 = new HeadersRequestCondition("header1");
+		this.header2 = new HeadersRequestCondition("header2");
+		this.header3 = this.header1.combine(this.header2);
+	}
+
+	@Test
+	public void combine() {
+		CompositeRequestCondition cond1 = new CompositeRequestCondition(this.param1, this.header1);
+		CompositeRequestCondition cond2 = new CompositeRequestCondition(this.param2, this.header2);
+		CompositeRequestCondition cond3 = new CompositeRequestCondition(this.param3, this.header3);
+
+		assertEquals(cond3, cond1.combine(cond2));
+	}
+
+	@Test
+	public void combineEmpty() {
+		CompositeRequestCondition empty = new CompositeRequestCondition();
+		CompositeRequestCondition notEmpty = new CompositeRequestCondition(this.param1);
+
+		assertSame(empty, empty.combine(empty));
+		assertSame(notEmpty, notEmpty.combine(empty));
+		assertSame(notEmpty, empty.combine(notEmpty));
+	}
+
+	@Test(expected=IllegalArgumentException.class)
+	public void combineDifferentLength() {
+		CompositeRequestCondition cond1 = new CompositeRequestCondition(this.param1);
+		CompositeRequestCondition cond2 = new CompositeRequestCondition(this.param1, this.header1);
+		cond1.combine(cond2);
+	}
+
+	@Test
+	public void match() {
+		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/");
+		request.setParameter("param1", "paramValue1");
+		request.addHeader("header1", "headerValue1");
+
+		RequestCondition<?> getPostCond = new RequestMethodsRequestCondition(RequestMethod.GET, RequestMethod.POST);
+		RequestCondition<?> getCond = new RequestMethodsRequestCondition(RequestMethod.GET);
+
+		CompositeRequestCondition condition = new CompositeRequestCondition(this.param1, getPostCond);
+		CompositeRequestCondition matchingCondition = new CompositeRequestCondition(this.param1, getCond);
+
+		assertEquals(matchingCondition, condition.getMatchingCondition(request));
+	}
+
+	@Test
+	public void noMatch() {
+		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/");
+		CompositeRequestCondition cond = new CompositeRequestCondition(this.param1);
+
+		assertNull(cond.getMatchingCondition(request));
+	}
+
+	@Test
+	public void matchEmpty() {
+		CompositeRequestCondition empty = new CompositeRequestCondition();
+		assertSame(empty, empty.getMatchingCondition(new MockHttpServletRequest()));
+	}
+
+	@Test
+	public void compare() {
+		HttpServletRequest request = new MockHttpServletRequest();
+
+		CompositeRequestCondition cond1 = new CompositeRequestCondition(this.param1);
+		CompositeRequestCondition cond3 = new CompositeRequestCondition(this.param3);
+
+		assertEquals(1, cond1.compareTo(cond3, request));
+		assertEquals(-1, cond3.compareTo(cond1, request));
+	}
+
+	@Test
+	public void compareEmpty() {
+		HttpServletRequest request = new MockHttpServletRequest();
+
+		CompositeRequestCondition empty = new CompositeRequestCondition();
+		CompositeRequestCondition notEmpty = new CompositeRequestCondition(this.param1);
+
+		assertEquals(0, empty.compareTo(empty, request));
+		assertEquals(-1, notEmpty.compareTo(empty, request));
+		assertEquals(1, empty.compareTo(notEmpty, request));
+	}
+
+	@Test(expected=IllegalArgumentException.class)
+	public void compareDifferentLength() {
+		CompositeRequestCondition cond1 = new CompositeRequestCondition(this.param1);
+		CompositeRequestCondition cond2 = new CompositeRequestCondition(this.param1, this.header1);
+		cond1.compareTo(cond2, new MockHttpServletRequest());
+	}
+
+}

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/condition/RequestConditionHolderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -27,23 +27,12 @@ import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.web.bind.annotation.RequestMethod;
 
 /**
- * A test fixture for
+ * A test fixture for {@link RequestConditionHolder} tests.
- * {code org.springframework.web.servlet.mvc.method.RequestConditionHolder} tests.
  *
  * @author Rossen Stoyanchev
  */
 public class RequestConditionHolderTests {
 
-	@Test
-	public void combineEmpty() {
-		RequestConditionHolder empty = new RequestConditionHolder(null);
-		RequestConditionHolder notEmpty = new RequestConditionHolder(new ParamsRequestCondition("name"));
-
-		assertSame(empty, empty.combine(new RequestConditionHolder(null)));
-		assertSame(notEmpty, notEmpty.combine(empty));
-		assertSame(notEmpty, empty.combine(notEmpty));
-	}
-
 	@Test
 	public void combine() {
 		RequestConditionHolder params1 = new RequestConditionHolder(new ParamsRequestCondition("name1"));
@@ -53,6 +42,16 @@ public class RequestConditionHolderTests {
 		assertEquals(expected, params1.combine(params2));
 	}
 
+	@Test
+	public void combineEmpty() {
+		RequestConditionHolder empty = new RequestConditionHolder(null);
+		RequestConditionHolder notEmpty = new RequestConditionHolder(new ParamsRequestCondition("name"));
+
+		assertSame(empty, empty.combine(empty));
+		assertSame(notEmpty, notEmpty.combine(empty));
+		assertSame(notEmpty, empty.combine(notEmpty));
+	}
+
 	@Test(expected=ClassCastException.class)
 	public void combineIncompatible() {
 		RequestConditionHolder params = new RequestConditionHolder(new ParamsRequestCondition("name"));

src/dist/changelog.txt

@@ -6,24 +6,25 @@ http://www.springsource.org
 Changes in version 3.2 M1
 -------------------------------------
 
+* add Servlet 3.0 based async support
 * upgraded to AspectJ 1.6.12, JUnit 4.10, TestNG 6.5.2
+* add HttpMessageConverter and View types compatible with Jackson 2.0
 * better handling on failure to parse invalid 'Content-Type' or 'Accept' headers
 * handle a controller method's return value based on the actual returned value (vs declared type)
 * fix issue with combining identical controller and method level request mapping paths
 * fix concurrency issue in AnnotationMethodHandlerExceptionResolver
 * fix case-sensitivity issue with some containers on access to 'Content-Disposition' header
-* add Servlet 3.0 based async support
 * fix issue with encoded params in UriComponentsBuilder
-* add HttpMessageConverter and View types compatible with Jackson 2.0
 * add pretty print option to Jackson HttpMessageConverter and View types
-* fix issue with resolving Errors controller method argument
-* detect controller methods via InitializingBean in RequestMappingHandlerMapping
 * translate IOException from Jackson to HttpMessageNotReadableException
+* fix issue with resolving Errors controller method argument
+* implement InitializingBean in RequestMappingHandlerMapping to detect controller methods
 * fix content negotiation issue when sorting selected media types by quality value
-* Prevent further writing to the response when @ResponseStatus contains a reason
+* prevent further writing to the response when @ResponseStatus contains a reason
-* Deprecate HttpStatus codes 419, 420, 421
+* deprecate HttpStatus codes 419, 420, 421
 * support access to all URI vars via @PathVariable Map<String, String>
 * add "excludedExceptions" property to SimpleUrlHandlerMapping
+* add CompositeRequestCondition for use with multiple custom request mapping conditions
 
 Changes in version 3.1.1 (2012-02-16)
 -------------------------------------