Make it easier to provide a placeholder resolver that uses the context

Closes gh-235

spring-restdocs-core/src/main/java/org/springframework/restdocs/config/RestDocumentationConfigurer.java

@@ -23,7 +23,7 @@ import java.util.Map;
 
 import org.springframework.restdocs.RestDocumentationContext;
 import org.springframework.restdocs.mustache.Mustache;
-import org.springframework.restdocs.snippet.RestDocumentationContextPlaceholderResolver;
+import org.springframework.restdocs.snippet.RestDocumentationContextPlaceholderResolverFactory;
 import org.springframework.restdocs.snippet.StandardWriterResolver;
 import org.springframework.restdocs.snippet.WriterResolver;
 import org.springframework.restdocs.templates.StandardTemplateResourceResolver;
@@ -138,7 +138,7 @@ public abstract class RestDocumentationConfigurer<S extends AbstractConfigurer,
 				SnippetConfiguration snippetConfiguration = (SnippetConfiguration) configuration
 						.get(SnippetConfiguration.class.getName());
 				resolverToUse = new StandardWriterResolver(
-						new RestDocumentationContextPlaceholderResolver(context),
+						new RestDocumentationContextPlaceholderResolverFactory(),
 						snippetConfiguration.getEncoding(),
 						snippetConfiguration.getTemplateFormat());
 			}

spring-restdocs-core/src/main/java/org/springframework/restdocs/snippet/PlaceholderResolverFactory.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2014-2016 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.restdocs.snippet;
+
+import org.springframework.restdocs.RestDocumentationContext;
+import org.springframework.util.PropertyPlaceholderHelper.PlaceholderResolver;
+
+/**
+ * A factory for creating {@link PlaceholderResolver} instances.
+ *
+ * @author Andy Wilkinson
+ * @since 1.1
+ */
+public interface PlaceholderResolverFactory {
+
+	/**
+	 * Creates a new {@link PlaceholderResolver} using the given {@code context}.
+	 *
+	 * @param context the context
+	 * @return the placeholder resolver
+	 */
+	PlaceholderResolver create(RestDocumentationContext context);
+
+}

spring-restdocs-core/src/main/java/org/springframework/restdocs/snippet/RestDocumentationContextPlaceholderResolverFactory.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2014-2016 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.restdocs.snippet;
+
+import org.springframework.restdocs.RestDocumentationContext;
+import org.springframework.util.PropertyPlaceholderHelper.PlaceholderResolver;
+
+/**
+ * A {@link PlaceholderResolverFactory} that creates
+ * {@link RestDocumentationContextPlaceholderResolver} instances.
+ *
+ * @author Andy Wilkinson
+ * @since 1.1
+ */
+public final class RestDocumentationContextPlaceholderResolverFactory
+		implements PlaceholderResolverFactory {
+
+	@Override
+	public PlaceholderResolver create(RestDocumentationContext context) {
+		return new RestDocumentationContextPlaceholderResolver(context);
+	}
+
+}

spring-restdocs-core/src/main/java/org/springframework/restdocs/snippet/StandardWriterResolver.java

@@ -35,7 +35,7 @@ import org.springframework.util.PropertyPlaceholderHelper.PlaceholderResolver;
  */
 public final class StandardWriterResolver implements WriterResolver {
 
-	private final PlaceholderResolver placeholderResolver;
+	private final PlaceholderResolverFactory placeholderResolverFactory;
 
 	private final PropertyPlaceholderHelper propertyPlaceholderHelper = new PropertyPlaceholderHelper(
 			"{", "}");
@@ -52,27 +52,29 @@ public final class StandardWriterResolver implements WriterResolver {
 	 *
 	 * @param placeholderResolver the placeholder resolver
 	 * @deprecated since 1.1.0 in favor of
-	 * {@link #StandardWriterResolver(PropertyPlaceholderHelper.PlaceholderResolver, String, TemplateFormat)}
+	 * {@link #StandardWriterResolver(PlaceholderResolverFactory, String, TemplateFormat)}
 	 */
 	@Deprecated
 	public StandardWriterResolver(PlaceholderResolver placeholderResolver) {
-		this(placeholderResolver, "UTF-8", TemplateFormats.asciidoctor());
+		this(new SingleInstancePlaceholderResolverFactory(placeholderResolver), "UTF-8",
+				TemplateFormats.asciidoctor());
 	}
 
 	/**
-	 * Creates a new {@code StandardWriterResolver} that will use the given
-	 * {@code placeholderResolver} to resolve any placeholders in the
+	 * Creates a new {@code StandardWriterResolver} that will use a
+	 * {@link PlaceholderResolver} created from the given
+	 * {@code placeholderResolverFactory} to resolve any placeholders in the
 	 * {@code operationName}. Writers will use the given {@code encoding} and, when
 	 * writing to a file, will use a filename appropriate for content generated from
 	 * templates in the given {@code templateFormat}.
 	 *
-	 * @param placeholderResolver the placeholder resolver
+	 * @param placeholderResolverFactory the placeholder resolver factory
 	 * @param encoding the encoding
 	 * @param templateFormat the snippet format
 	 */
-	public StandardWriterResolver(PlaceholderResolver placeholderResolver,
+	public StandardWriterResolver(PlaceholderResolverFactory placeholderResolverFactory,
 			String encoding, TemplateFormat templateFormat) {
-		this.placeholderResolver = placeholderResolver;
+		this.placeholderResolverFactory = placeholderResolverFactory;
 		this.encoding = encoding;
 		this.templateFormat = templateFormat;
 	}
@@ -82,7 +84,7 @@ public final class StandardWriterResolver implements WriterResolver {
 			RestDocumentationContext context) throws IOException {
 		File outputFile = resolveFile(
 				this.propertyPlaceholderHelper.replacePlaceholders(operationName,
-						this.placeholderResolver),
+						this.placeholderResolverFactory.create(context)),
 				snippetName + "." + this.templateFormat.getFileExtension(), context);
 
 		if (outputFile != null) {
@@ -127,4 +129,21 @@ public final class StandardWriterResolver implements WriterResolver {
 		}
 	}
 
+	private static final class SingleInstancePlaceholderResolverFactory
+			implements PlaceholderResolverFactory {
+
+		private final PlaceholderResolver placeholderResolver;
+
+		private SingleInstancePlaceholderResolverFactory(
+				PlaceholderResolver placeholderResolver) {
+			this.placeholderResolver = placeholderResolver;
+		}
+
+		@Override
+		public PlaceholderResolver create(RestDocumentationContext context) {
+			return this.placeholderResolver;
+		}
+
+	}
+
 }

spring-restdocs-core/src/test/java/org/springframework/restdocs/snippet/StandardWriterResolverTests.java

@@ -22,7 +22,6 @@ import org.junit.Test;
 
 import org.springframework.restdocs.ManualRestDocumentation;
 import org.springframework.restdocs.RestDocumentationContext;
-import org.springframework.util.PropertyPlaceholderHelper.PlaceholderResolver;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.assertThat;
@@ -36,11 +35,11 @@ import static org.springframework.restdocs.templates.TemplateFormats.asciidoctor
  */
 public class StandardWriterResolverTests {
 
-	private final PlaceholderResolver placeholderResolver = mock(
-			PlaceholderResolver.class);
+	private final PlaceholderResolverFactory placeholderResolverFactory = mock(
+			PlaceholderResolverFactory.class);
 
 	private final StandardWriterResolver resolver = new StandardWriterResolver(
-			this.placeholderResolver, "UTF-8", asciidoctor());
+			this.placeholderResolverFactory, "UTF-8", asciidoctor());
 
 	@Test
 	public void absoluteInput() {

spring-restdocs-core/src/test/java/org/springframework/restdocs/test/OperationBuilder.java

@@ -39,7 +39,7 @@ import org.springframework.restdocs.operation.OperationResponse;
 import org.springframework.restdocs.operation.OperationResponseFactory;
 import org.springframework.restdocs.operation.Parameters;
 import org.springframework.restdocs.operation.StandardOperation;
-import org.springframework.restdocs.snippet.RestDocumentationContextPlaceholderResolver;
+import org.springframework.restdocs.snippet.RestDocumentationContextPlaceholderResolverFactory;
 import org.springframework.restdocs.snippet.StandardWriterResolver;
 import org.springframework.restdocs.snippet.WriterResolver;
 import org.springframework.restdocs.templates.StandardTemplateResourceResolver;
@@ -107,7 +107,7 @@ public class OperationBuilder {
 		this.attributes.put(RestDocumentationContext.class.getName(), context);
 		this.attributes.put(WriterResolver.class.getName(),
 				new StandardWriterResolver(
-						new RestDocumentationContextPlaceholderResolver(context), "UTF-8",
+						new RestDocumentationContextPlaceholderResolverFactory(), "UTF-8",
 						this.templateFormat));
 		return new StandardOperation(this.name,
 				(this.requestBuilder == null