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 Encoder feignEncoder() {
 	@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;
+    }
+}