DATACMNS-744 - Removed strong dependency to Querydsl in web support.

Moved all Querydsl related bean definitions and customizations to a dedicated configuration class that only gets included if Querydsl is on the classpath.

Extracted a QuerydslActivator for use in Spring Data REST, which uses HateoasAwareSpringDataWebConfiguration via inheritance, not via @EnableSpringDataWebSupport.

Previously, we exposed a QuerydslBindingsFactory as bean method return type which breaks Spring bootstrap even if it's lazy due to its references to Querydsl types.

Related tickets: DATACMNS-669.

src/main/java/org/springframework/data/web/config/EnableSpringDataWebSupport.java

@@ -33,6 +33,7 @@ import org.springframework.core.env.Environment;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.core.type.AnnotationMetadata;
 import org.springframework.core.type.filter.AnnotationTypeFilter;
+import org.springframework.data.querydsl.QueryDslUtils;
 import org.springframework.data.web.PageableHandlerMethodArgumentResolver;
 import org.springframework.util.ClassUtils;
 
@@ -70,7 +71,8 @@ import org.springframework.util.ClassUtils;
 @Retention(RetentionPolicy.RUNTIME)
 @Target({ ElementType.TYPE, ElementType.ANNOTATION_TYPE })
 @Inherited
-@Import(EnableSpringDataWebSupport.SpringDataWebConfigurationImportSelector.class)
+@Import({ EnableSpringDataWebSupport.SpringDataWebConfigurationImportSelector.class,
+		EnableSpringDataWebSupport.QuerydslActivator.class })
 public @interface EnableSpringDataWebSupport {
 
 	/**
@@ -81,7 +83,8 @@ public @interface EnableSpringDataWebSupport {
 	 * 
 	 * @author Oliver Gierke
 	 */
-	class SpringDataWebConfigurationImportSelector implements ImportSelector, EnvironmentAware, ResourceLoaderAware {
+	static class SpringDataWebConfigurationImportSelector
+			implements ImportSelector, EnvironmentAware, ResourceLoaderAware {
 
 		// Don't make final to allow test cases faking this to false
 		private static boolean HATEOAS_PRESENT = ClassUtils.isPresent("org.springframework.hateoas.Link", null);
@@ -135,4 +138,25 @@ public @interface EnableSpringDataWebSupport {
 			return imports.toArray(new String[imports.size()]);
 		}
 	}
+
+	/**
+	 * Import selector to register {@link QuerydslWebConfiguration} as configuration class if Querydsl is on the
+	 * classpath.
+	 *
+	 * @author Oliver Gierke
+	 * @soundtrack Anika Nilles - Chary Life
+	 * @since 1.11
+	 */
+	static class QuerydslActivator implements ImportSelector {
+
+		/* 
+		 * (non-Javadoc)
+		 * @see org.springframework.context.annotation.ImportSelector#selectImports(org.springframework.core.type.AnnotationMetadata)
+		 */
+		@Override
+		public String[] selectImports(AnnotationMetadata importingClassMetadata) {
+			return QueryDslUtils.QUERY_DSL_PRESENT ? new String[] { QuerydslWebConfiguration.class.getName() }
+					: new String[0];
+		}
+	}
 }

src/main/java/org/springframework/data/web/config/QuerydslWebConfiguration.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2015 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.data.web.config;
+
+import java.util.List;
+
+import org.springframework.beans.factory.ObjectFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Lazy;
+import org.springframework.core.convert.ConversionService;
+import org.springframework.data.querydsl.SimpleEntityPathResolver;
+import org.springframework.data.querydsl.binding.QuerydslBindingsFactory;
+import org.springframework.data.web.querydsl.QuerydslPredicateArgumentResolver;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
+
+import com.mysema.query.types.Predicate;
+
+/**
+ * Querydsl-specific web configuration for Spring Data. Registers a {@link HandlerMethodArgumentResolver} that builds up
+ * {@link Predicate}s from web requests.
+ * 
+ * @author Oliver Gierke
+ * @since 1.11
+ * @soundtrack Anika Nilles - Alter Ego
+ */
+@Configuration
+public class QuerydslWebConfiguration extends WebMvcConfigurerAdapter {
+
+	@Autowired @Qualifier("mvcConversionService") ObjectFactory<ConversionService> conversionService;
+
+	/**
+	 * Default {@link QuerydslPredicateArgumentResolver} to create Querydsl {@link Predicate} instances for Spring MVC
+	 * controller methods.
+	 * 
+	 * @return
+	 */
+	@Lazy
+	@Bean
+	public QuerydslPredicateArgumentResolver querydslPredicateArgumentResolver() {
+		return new QuerydslPredicateArgumentResolver(querydslBindingsFactory(), conversionService.getObject());
+	}
+
+	@Lazy
+	@Bean
+	public QuerydslBindingsFactory querydslBindingsFactory() {
+		return new QuerydslBindingsFactory(SimpleEntityPathResolver.INSTANCE);
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter#addArgumentResolvers(java.util.List)
+	 */
+	@Override
+	public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
+		argumentResolvers.add(0, querydslPredicateArgumentResolver());
+	}
+}

src/main/java/org/springframework/data/web/config/SpringDataWebConfiguration.java

@@ -23,25 +23,18 @@ import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.context.annotation.Lazy;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.data.geo.format.DistanceFormatter;
 import org.springframework.data.geo.format.PointFormatter;
-import org.springframework.data.querydsl.QueryDslUtils;
-import org.springframework.data.querydsl.SimpleEntityPathResolver;
-import org.springframework.data.querydsl.binding.QuerydslBindingsFactory;
 import org.springframework.data.repository.support.DomainClassConverter;
 import org.springframework.data.web.PageableHandlerMethodArgumentResolver;
 import org.springframework.data.web.ProxyingHandlerMethodArgumentResolver;
 import org.springframework.data.web.SortHandlerMethodArgumentResolver;
-import org.springframework.data.web.querydsl.QuerydslPredicateArgumentResolver;
 import org.springframework.format.FormatterRegistry;
 import org.springframework.format.support.FormattingConversionService;
 import org.springframework.web.method.support.HandlerMethodArgumentResolver;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
 
-import com.mysema.query.types.Predicate;
-
 /**
  * Configuration class to register {@link PageableHandlerMethodArgumentResolver},
  * {@link SortHandlerMethodArgumentResolver} and {@link DomainClassConverter}.
@@ -73,24 +66,6 @@ public class SpringDataWebConfiguration extends WebMvcConfigurerAdapter {
 		return new SortHandlerMethodArgumentResolver();
 	}
 
-	/**
-	 * Default {@link QuerydslPredicateArgumentResolver} to create Querydsl {@link Predicate} instances for Spring MVC
-	 * controller methods.
-	 * 
-	 * @return
-	 */
-	@Lazy
-	@Bean
-	public HandlerMethodArgumentResolver querydslPredicateArgumentResolver() {
-		return new QuerydslPredicateArgumentResolver(querydslBindingsFactory(), conversionService.getObject());
-	}
-
-	@Lazy
-	@Bean
-	public QuerydslBindingsFactory querydslBindingsFactory() {
-		return new QuerydslBindingsFactory(SimpleEntityPathResolver.INSTANCE);
-	}
-
 	/* 
 	 * (non-Javadoc)
 	 * @see org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter#addFormatters(org.springframework.format.FormatterRegistry)
@@ -122,10 +97,6 @@ public class SpringDataWebConfiguration extends WebMvcConfigurerAdapter {
 		argumentResolvers.add(sortResolver());
 		argumentResolvers.add(pageableResolver());
 
-		if (QueryDslUtils.QUERY_DSL_PRESENT) {
-			argumentResolvers.add(querydslPredicateArgumentResolver());
-		}
-
 		ProxyingHandlerMethodArgumentResolver resolver = new ProxyingHandlerMethodArgumentResolver(
 				conversionService.getObject());
 		resolver.setBeanFactory(context);
@@ -133,5 +104,4 @@ public class SpringDataWebConfiguration extends WebMvcConfigurerAdapter {
 
 		argumentResolvers.add(resolver);
 	}
-
 }