Feign annotated parameter processors

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/AnnotatedParameterProcessor.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2013-2015 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.cloud.netflix.feign;
+
+import java.lang.annotation.Annotation;
+import java.util.Collection;
+
+import feign.MethodMetadata;
+
+/**
+ * Feign contract method parameter processor.
+ *
+ * @author Jakub Narloch
+ */
+public interface AnnotatedParameterProcessor {
+
+	/**
+	 * Retrieves the processor supported annotation type.
+	 *
+	 * @return the annotation type
+	 */
+	Class<? extends Annotation> getAnnotationType();
+
+	/**
+	 * Process the annotated parameter.
+	 *
+	 * @param context    the parameter context
+	 * @param annotation the annotation instance
+	 * @return whether the parameter is http
+	 */
+	boolean processArgument(AnnotatedParameterContext context, Annotation annotation);
+
+	/**
+	 * Specifies the parameter context.
+	 *
+	 * @author Jakub Narloch
+	 */
+	interface AnnotatedParameterContext {
+
+		/**
+		 * Retrieves the method metadata.
+		 *
+		 * @return the method metadata
+		 */
+		MethodMetadata getMethodMetadata();
+
+		/**
+		 * Retrieves the index of the parameter.
+		 *
+		 * @return the parameter index
+		 */
+		int getParameterIndex();
+
+		/**
+		 * Sets the parameter name.
+		 *
+		 * @param name the name of the parameter
+		 */
+		void setParameterName(String name);
+
+		/**
+		 * Sets the template parameter.
+		 *
+		 * @param name the template parameter
+		 * @param rest the existing parameter values
+		 * @return parameters
+		 */
+		Collection<String> setTemplateParameter(String name, Collection<String> rest);
+	}
+}

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/FeignClientsConfiguration.java

@@ -16,6 +16,9 @@
 
 package org.springframework.cloud.netflix.feign;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import org.apache.http.client.HttpClient;
 import org.springframework.beans.factory.ObjectFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -44,6 +47,9 @@ public class FeignClientsConfiguration {
 	@Autowired
 	private ObjectFactory<HttpMessageConverters> messageConverters;
 
+	@Autowired(required = false)
+	private List<AnnotatedParameterProcessor> parameterProcessors = new ArrayList<>();
+
 	@Bean
 	@ConditionalOnMissingBean
 	public Decoder feignDecoder() {
@@ -59,7 +65,7 @@ public class FeignClientsConfiguration {
 	@Bean
 	@ConditionalOnMissingBean
 	public Contract feignContract() {
-		return new SpringMvcContract();
+		return new SpringMvcContract(parameterProcessors);
 	}
 
 	@Configuration

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/annotation/PathVariableParameterProcessor.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2013-2015 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.cloud.netflix.feign.annotation;
+
+import java.lang.annotation.Annotation;
+import java.util.Collection;
+import java.util.Map;
+
+import org.springframework.cloud.netflix.feign.AnnotatedParameterProcessor;
+import org.springframework.web.bind.annotation.PathVariable;
+
+import feign.MethodMetadata;
+
+import static feign.Util.checkState;
+import static feign.Util.emptyToNull;
+
+/**
+ * {@link PathVariable} parameter processor.
+ *
+ * @author Jakub Narloch
+ * @see AnnotatedParameterProcessor
+ */
+public class PathVariableParameterProcessor implements AnnotatedParameterProcessor {
+
+    private static final Class<PathVariable> ANNOTATION = PathVariable.class;
+
+    @Override
+    public Class<? extends Annotation> getAnnotationType() {
+        return ANNOTATION;
+    }
+
+    @Override
+    public boolean processArgument(AnnotatedParameterContext context, Annotation annotation) {
+        String name = ANNOTATION.cast(annotation).value();
+        checkState(emptyToNull(name) != null,
+                "PathVariable annotation was empty on param %s.", context.getParameterIndex());
+        context.setParameterName(name);
+
+        MethodMetadata data = context.getMethodMetadata();
+        String varName = '{' + name + '}';
+        if (!data.template().url().contains(varName)
+                && !searchMapValues(data.template().queries(), varName)
+                && !searchMapValues(data.template().headers(), varName)) {
+            data.formParams().add(name);
+        }
+        return true;
+    }
+
+    private <K, V> boolean searchMapValues(Map<K, Collection<V>> map, V search) {
+        Collection<Collection<V>> values = map.values();
+        if (values == null) {
+            return false;
+        }
+        for (Collection<V> entry : values) {
+            if (entry.contains(search)) {
+                return true;
+            }
+        }
+        return false;
+    }
+}

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/annotation/RequestHeaderParameterProcessor.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2013-2015 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.cloud.netflix.feign.annotation;
+
+import java.lang.annotation.Annotation;
+import java.util.Collection;
+
+import org.springframework.cloud.netflix.feign.AnnotatedParameterProcessor;
+import org.springframework.web.bind.annotation.RequestHeader;
+
+import feign.MethodMetadata;
+
+import static feign.Util.checkState;
+import static feign.Util.emptyToNull;
+
+/**
+ * {@link RequestHeader} parameter processor.
+ *
+ * @author Jakub Narloch
+ * @see AnnotatedParameterProcessor
+ */
+public class RequestHeaderParameterProcessor implements AnnotatedParameterProcessor {
+
+    private static final Class<RequestHeader> ANNOTATION = RequestHeader.class;
+
+    @Override
+    public Class<? extends Annotation> getAnnotationType() {
+        return ANNOTATION;
+    }
+
+    @Override
+    public boolean processArgument(AnnotatedParameterContext context, Annotation annotation) {
+        String name = ANNOTATION.cast(annotation).value();
+        checkState(emptyToNull(name) != null,
+                "RequestHeader.value() was empty on parameter %s", context.getParameterIndex());
+        context.setParameterName(name);
+
+        MethodMetadata data = context.getMethodMetadata();
+        Collection<String> header = context.setTemplateParameter(name, data.template().headers().get(name));
+        data.template().header(name, header);
+        return true;
+    }
+}

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/annotation/RequestParamParameterProcessor.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2013-2015 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.cloud.netflix.feign.annotation;
+
+import java.lang.annotation.Annotation;
+import java.util.Collection;
+
+import org.springframework.cloud.netflix.feign.AnnotatedParameterProcessor;
+import org.springframework.web.bind.annotation.RequestParam;
+
+import feign.MethodMetadata;
+
+import static feign.Util.checkState;
+import static feign.Util.emptyToNull;
+
+/**
+ * {@link RequestParam} parameter processor.
+ *
+ * @author Jakub Narloch
+ * @see AnnotatedParameterProcessor
+ */
+public class RequestParamParameterProcessor implements AnnotatedParameterProcessor {
+
+    private static final Class<RequestParam> ANNOTATION = RequestParam.class;
+
+    @Override
+    public Class<? extends Annotation> getAnnotationType() {
+        return ANNOTATION;
+    }
+
+    @Override
+    public boolean processArgument(AnnotatedParameterContext context, Annotation annotation) {
+        String name = ANNOTATION.cast(annotation).value();
+        checkState(emptyToNull(name) != null,
+                "RequestParam.value() was empty on parameter %s", context.getParameterIndex());
+        context.setParameterName(name);
+
+        MethodMetadata data = context.getMethodMetadata();
+        Collection<String> query = context.setTemplateParameter(name, data.template().queries().get(name));
+        data.template().query(name, query);
+        return true;
+    }
+}

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/support/SpringMvcContract.java

@@ -16,19 +16,26 @@
 
 package org.springframework.cloud.netflix.feign.support;
 
-import feign.Contract;
-import feign.MethodMetadata;
-import org.springframework.web.bind.annotation.PathVariable;
-import org.springframework.web.bind.annotation.RequestHeader;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestParam;
-
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Method;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
+import org.springframework.cloud.netflix.feign.AnnotatedParameterProcessor;
+import org.springframework.cloud.netflix.feign.annotation.PathVariableParameterProcessor;
+import org.springframework.cloud.netflix.feign.annotation.RequestHeaderParameterProcessor;
+import org.springframework.cloud.netflix.feign.annotation.RequestParamParameterProcessor;
+import org.springframework.util.Assert;
+import org.springframework.web.bind.annotation.RequestMapping;
+
+import feign.Contract;
+import feign.MethodMetadata;
+
 import static feign.Util.checkState;
 import static feign.Util.emptyToNull;
 
@@ -41,6 +48,24 @@ public class SpringMvcContract extends Contract.BaseContract {
 
 	private static final String CONTENT_TYPE = "Content-Type";
 
+	private final Map<Class<? extends Annotation>, AnnotatedParameterProcessor> annotatedArgumentProcessors;
+
+	public SpringMvcContract() {
+		this(Collections.<AnnotatedParameterProcessor>emptyList());
+	}
+
+	public SpringMvcContract(List<AnnotatedParameterProcessor> annotatedParameterProcessors) {
+		Assert.notNull(annotatedParameterProcessors, "Parameter processors can not be null.");
+
+		List<AnnotatedParameterProcessor> processors;
+		if(!annotatedParameterProcessors.isEmpty()) {
+			processors = new ArrayList<>(annotatedParameterProcessors);
+		} else {
+			processors = getDefaultAnnotatedArgumentsProcessors();
+		}
+		this.annotatedArgumentProcessors = toAnnotatedArgumentProcessorMap(processors);
+	}
+
 	@Override
 	public MethodMetadata parseAndValidateMetadata(Class<?> targetType, Method method) {
 		MethodMetadata md = super.parseAndValidateMetadata(targetType, method);
@@ -109,6 +134,7 @@ public class SpringMvcContract extends Contract.BaseContract {
 		parseHeaders(data, method, methodMapping);
 	}
 
+
 	private void checkAtMostOne(Method method, Object[] values, String fieldName) {
 		checkState(values != null && (values.length == 0 || values.length == 1),
 				"Method %s can only contain at most 1 %s field. Found: %s",
@@ -123,72 +149,19 @@ public class SpringMvcContract extends Contract.BaseContract {
 	}
 
 	@Override
-	protected boolean processAnnotationsOnParameter(MethodMetadata data,
-			Annotation[] annotations, int paramIndex) {
+	protected boolean processAnnotationsOnParameter(MethodMetadata data, Annotation[] annotations, int paramIndex) {
 		boolean isHttpAnnotation = false;
-		// TODO: support spring parameter annotations?
+
+		AnnotatedParameterProcessor.AnnotatedParameterContext context =
+				new SimpleAnnotatedParameterContext(data, paramIndex);
 		for (Annotation parameterAnnotation : annotations) {
-			if (parameterAnnotation instanceof PathVariable) {
-				String name = PathVariable.class.cast(parameterAnnotation).value();
-				checkState(emptyToNull(name) != null,
-						"PathVariable annotation was empty on param %s.", paramIndex);
-				nameParam(data, name, paramIndex);
-				isHttpAnnotation = true;
-				String varName = '{' + name + '}';
-				if (data.template().url().indexOf(varName) == -1
-						&& !searchMapValues(data.template().queries(), varName)
-						&& !searchMapValues(data.template().headers(), varName)) {
-					data.formParams().add(name);
-				}
-			}
-			else if (parameterAnnotation instanceof RequestParam) {
-				String name = RequestParam.class.cast(parameterAnnotation).value();
-				checkState(emptyToNull(name) != null,
-						"QueryParam.value() was empty on parameter %s", paramIndex);
-				Collection<String> query = addTemplatedParam(data.template().queries()
-						.get(name), name);
-				data.template().query(name, query);
-				nameParam(data, name, paramIndex);
-				isHttpAnnotation = true;
-			}
-			else if (parameterAnnotation instanceof RequestHeader) {
-				String name = RequestHeader.class.cast(parameterAnnotation).value();
-				checkState(emptyToNull(name) != null,
-						"HeaderParam.value() was empty on parameter %s", paramIndex);
-				Collection<String> header = addTemplatedParam(data.template().headers()
-						.get(name), name);
-				data.template().header(name, header);
-				nameParam(data, name, paramIndex);
-				isHttpAnnotation = true;
-			}
-
-			// TODO
-			/*
-			 * else if (annotationType == FormParam.class) { String name =
-			 * FormParam.class.cast(parameterAnnotation).value();
-			 * checkState(emptyToNull(name) != null,
-			 * "FormParam.value() was empty on parameter %s", paramIndex);
-			 * data.formParams().add(name); nameParam(data, name, paramIndex);
-			 * isHttpAnnotation = true; }
-			 */
-
+			AnnotatedParameterProcessor processor =
+					annotatedArgumentProcessors.get(parameterAnnotation.annotationType());
+			isHttpAnnotation |= processor.processArgument(context, parameterAnnotation);
 		}
 		return isHttpAnnotation;
 	}
 
-	private <K, V> boolean searchMapValues(Map<K, Collection<V>> map, V search) {
-		Collection<Collection<V>> values = map.values();
-		if (values == null) {
-			return false;
-		}
-		for (Collection<V> entry : values) {
-			if (entry.contains(search)) {
-				return true;
-			}
-		}
-		return false;
-	}
-
 	private void parseProduces(MethodMetadata md, Method method, RequestMapping annotation) {
 		checkAtMostOne(method, annotation.produces(), "produces");
 		String[] serverProduces = annotation.produces();
@@ -220,4 +193,55 @@ public class SpringMvcContract extends Contract.BaseContract {
 		}
 	}
 
+	private Map<Class<? extends Annotation>, AnnotatedParameterProcessor> toAnnotatedArgumentProcessorMap(List<AnnotatedParameterProcessor> processors) {
+		Map<Class<? extends Annotation>, AnnotatedParameterProcessor> result = new HashMap<>();
+		for(AnnotatedParameterProcessor processor : processors) {
+			result.put(processor.getAnnotationType(), processor);
+		}
+		return result;
+	}
+
+	private List<AnnotatedParameterProcessor> getDefaultAnnotatedArgumentsProcessors() {
+
+		List<AnnotatedParameterProcessor> annotatedArgumentResolvers = new ArrayList<>();
+
+		annotatedArgumentResolvers.add(new PathVariableParameterProcessor());
+		annotatedArgumentResolvers.add(new RequestParamParameterProcessor());
+		annotatedArgumentResolvers.add(new RequestHeaderParameterProcessor());
+
+		return annotatedArgumentResolvers;
+	}
+
+	private class SimpleAnnotatedParameterContext implements AnnotatedParameterProcessor.AnnotatedParameterContext {
+
+		private final MethodMetadata methodMetadata;
+
+		private final int parameterIndex;
+
+		public SimpleAnnotatedParameterContext(MethodMetadata methodMetadata, int parameterIndex) {
+			this.methodMetadata = methodMetadata;
+			this.parameterIndex = parameterIndex;
+		}
+
+		@Override
+		public MethodMetadata getMethodMetadata() {
+			return methodMetadata;
+		}
+
+		@Override
+		public int getParameterIndex() {
+			return parameterIndex;
+		}
+
+		@Override
+		public void setParameterName(String name) {
+			nameParam(methodMetadata, name, parameterIndex);
+		}
+
+		@Override
+		public Collection<String> setTemplateParameter(String name, Collection<String> rest) {
+			return addTemplatedParam(rest, name);
+		}
+	}
+
 }

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/feign/support/SpringMvcContractTest.java

@@ -1,13 +1,7 @@
 package org.springframework.cloud.netflix.feign.support;
 
-import static org.junit.Assert.assertEquals;
-
 import java.lang.reflect.Method;
 
-import lombok.AllArgsConstructor;
-import lombok.NoArgsConstructor;
-import lombok.ToString;
-
 import org.junit.Before;
 import org.junit.Test;
 import org.springframework.http.MediaType;
@@ -22,6 +16,11 @@ import org.springframework.web.bind.annotation.RequestParam;
 import com.fasterxml.jackson.annotation.JsonAutoDetect;
 
 import feign.MethodMetadata;
+import lombok.AllArgsConstructor;
+import lombok.NoArgsConstructor;
+import lombok.ToString;
+
+import static org.junit.Assert.assertEquals;
 
 /**
  * @author chadjaros