Sort Support for feign pagination

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

@@ -42,6 +42,7 @@
 import org.springframework.cloud.openfeign.support.PageJacksonModule;
 import org.springframework.cloud.openfeign.support.PageableSpringEncoder;
 import org.springframework.cloud.openfeign.support.ResponseEntityDecoder;
+import org.springframework.cloud.openfeign.support.SortJacksonModule;
 import org.springframework.cloud.openfeign.support.SpringDecoder;
 import org.springframework.cloud.openfeign.support.SpringEncoder;
 import org.springframework.cloud.openfeign.support.SpringMvcContract;
@@ -150,6 +151,12 @@ public Module pageJacksonModule() {
 		return new PageJacksonModule();
 	}
 
+	@Bean
+	@ConditionalOnClass(name = "org.springframework.data.domain.Page")
+	public Module sortModule() {
+		return new SortJacksonModule();
+	}
+
 	private Encoder springEncoder(ObjectProvider<AbstractFormWriter> formWriterProvider) {
 		AbstractFormWriter formWriter = formWriterProvider.getIfAvailable();
 

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/support/PageJacksonModule.java

@@ -65,9 +65,17 @@ static class SimplePageImpl<T> implements Page<T> {
 
 		SimplePageImpl(@JsonProperty("content") List<T> content,
 				@JsonProperty("number") int number, @JsonProperty("size") int size,
-				@JsonProperty("totalElements") long totalElements) {
-			delegate = new PageImpl<>(content, PageRequest.of(number, size),
-					totalElements);
+				@JsonProperty("totalElements") long totalElements,
+				@JsonProperty("sort") Sort sort) {
+			PageRequest pageRequest;
+			if (sort != null) {
+				pageRequest = PageRequest.of(number, size, sort);
+			}
+			else {
+				pageRequest = PageRequest.of(number, size);
+			}
+			delegate = new PageImpl<>(content, pageRequest, totalElements);
+
 		}
 
 		@JsonProperty

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/support/SortJacksonModule.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2013-2020 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
+ *
+ *      https://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.openfeign.support;
+
+import com.fasterxml.jackson.core.Version;
+import com.fasterxml.jackson.databind.Module;
+import com.fasterxml.jackson.databind.module.SimpleDeserializers;
+import com.fasterxml.jackson.databind.module.SimpleSerializers;
+
+import org.springframework.data.domain.Sort;
+
+/**
+ * This jackson module provides support to add serialize and deserialize for spring
+ * {@link Sort} object.
+ *
+ * @author canbezmen
+ */
+public class SortJacksonModule extends Module {
+
+	@Override
+	public String getModuleName() {
+		return "SortModule";
+	}
+
+	@Override
+	public Version version() {
+		return new Version(0, 1, 0, "", null, null);
+	}
+
+	@Override
+	public void setupModule(SetupContext context) {
+		SimpleSerializers serializers = new SimpleSerializers();
+		serializers.addSerializer(Sort.class, new SortJsonComponent.SortSerializer());
+		context.addSerializers(serializers);
+
+		SimpleDeserializers deserializers = new SimpleDeserializers();
+		deserializers.addDeserializer(Sort.class,
+				new SortJsonComponent.SortDeserializer());
+		context.addDeserializers(deserializers);
+	}
+
+}

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/support/SortJsonComponent.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright 2013-2020 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
+ *
+ *      https://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.openfeign.support;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.TreeNode;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+
+import org.springframework.data.domain.Sort;
+
+/**
+ * This class provides support to serialize and deserialize spring {@link Sort} object.
+ *
+ * @author canbezmen
+ */
+public class SortJsonComponent {
+
+	public static class SortSerializer extends JsonSerializer<Sort> {
+
+		@Override
+		public void serialize(Sort value, JsonGenerator gen,
+				SerializerProvider serializers) throws IOException {
+			gen.writeStartArray();
+			value.iterator().forEachRemaining(v -> {
+				try {
+					gen.writeObject(v);
+				}
+				catch (IOException e) {
+					e.printStackTrace();
+				}
+			});
+			gen.writeEndArray();
+		}
+
+		@Override
+		public Class<Sort> handledType() {
+			return Sort.class;
+		}
+
+	}
+
+	public static class SortDeserializer extends JsonDeserializer<Sort> {
+
+		@Override
+		public Sort deserialize(JsonParser jsonParser,
+				DeserializationContext deserializationContext) throws IOException {
+			TreeNode treeNode = jsonParser.getCodec().readTree(jsonParser);
+			if (treeNode.isArray()) {
+				ArrayNode arrayNode = (ArrayNode) treeNode;
+				List<Sort.Order> orders = new ArrayList<>();
+				for (JsonNode jsonNode : arrayNode) {
+					Sort.Order order = new Sort.Order(
+							Sort.Direction.valueOf(jsonNode.get("direction").textValue()),
+							jsonNode.get("property").textValue());
+					orders.add(order);
+				}
+				return Sort.by(orders);
+			}
+			return null;
+		}
+
+		@Override
+		public Class<Sort> handledType() {
+			return Sort.class;
+		}
+
+	}
+
+}

spring-cloud-openfeign-core/src/test/java/org/springframework/cloud/openfeign/encoding/FeignPageableEncodingTests.java

@@ -16,6 +16,8 @@
 
 package org.springframework.cloud.openfeign.encoding;
 
+import java.util.Optional;
+
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
@@ -78,6 +80,14 @@ public void testPageable() {
 		assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK);
 		assertThat(response.getBody()).isNotNull();
 		assertThat(pageable.getPageSize()).isEqualTo(response.getBody().getSize());
+		assertThat(response.getBody().getPageable().getSort()).hasSize(1);
+		Optional<Sort.Order> optionalOrder = response.getBody().getPageable().getSort()
+				.get().findFirst();
+		if (optionalOrder.isPresent()) {
+			Sort.Order order = optionalOrder.get();
+			assertThat(order.getDirection()).isEqualTo(Sort.Direction.ASC);
+			assertThat(order.getProperty()).isEqualTo("sortProperty");
+		}
 
 	}
 

spring-cloud-openfeign-core/src/test/java/org/springframework/cloud/openfeign/support/SortJacksonModuleTests.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2013-2020 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
+ *
+ *      https://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.openfeign.support;
+
+import java.util.Optional;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Sort;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author canbezmen
+ */
+class SortJacksonModuleTests {
+
+	private static ObjectMapper objectMapper;
+
+	@BeforeAll
+	public static void initialize() {
+		objectMapper = new ObjectMapper();
+		objectMapper.registerModules(new PageJacksonModule());
+		objectMapper.registerModule(new SortJacksonModule());
+	}
+
+	@Test
+	public void deserializePage() throws JsonProcessingException {
+		// Given
+		String pageJson = "{\"content\":[\"A name\"],\"number\":1,\"size\":2,\"totalElements\":3,\"sort\":[{\"direction\":\"ASC\",\"property\":\"field\",\"ignoreCase\":false,\"nullHandling\":\"NATIVE\",\"descending\":false,\"ascending\":true}]}";
+		// When
+		Page<?> result = objectMapper.readValue(pageJson, Page.class);
+		// Then
+		assertThat(result).isNotNull();
+		assertThat(result.getTotalElements()).isEqualTo(3);
+		assertThat(result.getContent()).hasSize(1);
+		assertThat(result.getPageable()).isNotNull();
+		assertThat(result.getPageable().getPageSize()).isEqualTo(2);
+		assertThat(result.getPageable().getPageNumber()).isEqualTo(1);
+		assertThat(result.getPageable().getSort()).hasSize(1);
+		Optional<Sort.Order> optionalOrder = result.getPageable().getSort().get()
+				.findFirst();
+		if (optionalOrder.isPresent()) {
+			Sort.Order order = optionalOrder.get();
+			assertThat(order.getDirection()).isEqualTo(Sort.Direction.ASC);
+			assertThat(order.getProperty()).isEqualTo("field");
+		}
+	}
+
+}