feature(sample-service-cassandra): adding pagination to sample

data/data-samples/sample-data-cassandra-reactive/src/main/java/io/americanexpress/data/book/repository/BookRepository.java

@@ -14,8 +14,11 @@
 package io.americanexpress.data.book.repository;
 
 import io.americanexpress.data.book.entity.BookEntity;
+import org.springframework.data.cassandra.core.query.CassandraPageRequest;
 import org.springframework.data.cassandra.repository.AllowFiltering;
 import org.springframework.data.cassandra.repository.ReactiveCassandraRepository;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Slice;
 import org.springframework.stereotype.Repository;
 import reactor.core.publisher.Mono;
 
@@ -31,4 +34,7 @@ public interface BookRepository extends ReactiveCassandraRepository<BookEntity,
 
     @AllowFiltering
     Mono<BookEntity> findByTitle(String title);
+
+    Mono<Slice<BookEntity>> findAllBy(Pageable pageable);
+
 }

service/service-samples/sample-service-reactive-cassandra-book/src/main/java/io/americanexpress/service/book/rest/controller/ReadPolyBookReactiveController.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2020 American Express Travel Related Services Company, Inc.
+ *
+ * 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 io.americanexpress.service.book.rest.controller;
+
+import io.americanexpress.service.book.rest.config.BookEndpoints;
+import io.americanexpress.service.book.rest.model.ReadBookResponse;
+import io.americanexpress.service.book.rest.model.ReadBookPaginatedRequest;
+import io.americanexpress.service.book.rest.service.ReadPolyBookReactiveService;
+import io.americanexpress.synapse.service.rest.controller.reactive.BaseReadPolyReactiveController;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * {@code ReadPolyBookReactiveController} is the controller class for retrieving books from the Cassandra Book database.
+ */
+@RestController
+@RequestMapping(BookEndpoints.BOOK_ENDPOINT)
+public class ReadPolyBookReactiveController extends BaseReadPolyReactiveController<ReadBookPaginatedRequest, ReadBookResponse, ReadPolyBookReactiveService> {
+}

service/service-samples/sample-service-reactive-cassandra-book/src/main/java/io/americanexpress/service/book/rest/model/ReadBookPaginatedRequest.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2020 American Express Travel Related Services Company, Inc.
+ *
+ * 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 io.americanexpress.service.book.rest.model;
+
+import io.americanexpress.synapse.service.rest.model.BasePaginatedServiceRequest;
+
+
+/**
+ * {@code ReadBookPaginatedRequest} is the request object for reading book paginated.
+ */
+public class ReadBookPaginatedRequest extends BasePaginatedServiceRequest {
+
+}

service/service-samples/sample-service-reactive-cassandra-book/src/main/java/io/americanexpress/service/book/rest/service/ReadPolyBookReactiveService.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2020 American Express Travel Related Services Company, Inc.
+ *
+ * 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 io.americanexpress.service.book.rest.service;
+
+import io.americanexpress.data.book.entity.BookEntity;
+import io.americanexpress.data.book.repository.BookRepository;
+import io.americanexpress.service.book.rest.model.ReadBookResponse;
+import io.americanexpress.service.book.rest.model.ReadBookPaginatedRequest;
+import io.americanexpress.service.book.rest.service.helper.ReadBookResponseCreator;
+import io.americanexpress.synapse.service.rest.model.PageInformation;
+import io.americanexpress.synapse.service.rest.service.reactive.BaseReadPolyReactiveService;
+import org.springframework.data.cassandra.core.query.CassandraPageRequest;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Slice;
+import org.springframework.http.HttpHeaders;
+import org.springframework.stereotype.Service;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import java.nio.ByteBuffer;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * {@code ReadPolyBookReactiveService} is the service class for retrieving books from the Cassandra Book database.
+ */
+@Service
+public class ReadPolyBookReactiveService extends BaseReadPolyReactiveService<ReadBookPaginatedRequest, ReadBookResponse> {
+
+    private final BookRepository bookRepository;
+
+    private Map<PageInformation, ByteBuffer> pageInformationPagingStateMap = new HashMap<>();
+
+
+    /**
+     * Instantiates a new Read poly book reactive service.
+     *
+     * @param bookRepository the book repository
+     */
+    public ReadPolyBookReactiveService(BookRepository bookRepository) {
+        this.bookRepository = bookRepository;
+    }
+
+    @Override
+    protected Flux<ReadBookResponse> executeRead(HttpHeaders headers, ReadBookPaginatedRequest request) {
+        Flux<ReadBookResponse> readBookResponseFlux;
+        if(request.getPageInformation() != null) {
+            Pageable pageable = PageRequest.of(0, request.getPageInformation().getSize());
+            Pageable cassandraPageable = CassandraPageRequest.of(pageable, getPageState(request.getPageInformation()));
+            Mono<Slice<BookEntity>> bookEntityList = bookRepository.findAllBy(cassandraPageable);
+            bookEntityList.map(Slice::nextOrLastPageable).subscribe(nextPageable -> addPageState(request.getPageInformation(), (CassandraPageRequest) nextPageable));
+            return bookEntityList.flatMapMany(Flux::fromIterable).map(ReadBookResponseCreator::create);
+        }else {
+            readBookResponseFlux = bookRepository.findAll()
+                    .map(ReadBookResponseCreator::create)
+                    .switchIfEmpty(Flux.empty());
+        }
+       return readBookResponseFlux;
+    }
+    private ByteBuffer getPageState(PageInformation pageInformation) {
+        return pageInformationPagingStateMap.get(pageInformation);
+    }
+
+    private void addPageState(PageInformation pageInformation, CassandraPageRequest nextOrLastPageable) {
+        System.out.println("AddPageState");
+        if(nextOrLastPageable.getPagingState() != null ) {
+            pageInformation.setPage(pageInformation.getPage() + 1);
+            pageInformationPagingStateMap.put(pageInformation, nextOrLastPageable.getPagingState());
+        }
+    }
+}
+

service/service-samples/sample-service-rest-cassandra-book/src/main/java/io/americanexpress/service/book/rest/controller/ReadPolyBookController.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2020 American Express Travel Related Services Company, Inc.
+ *
+ * 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 io.americanexpress.service.book.rest.controller;
+
+import io.americanexpress.service.book.rest.config.BookEndpoints;
+import io.americanexpress.service.book.rest.model.ReadBookPaginatedRequest;
+import io.americanexpress.service.book.rest.model.ReadBookResponse;
+import io.americanexpress.service.book.rest.service.ReadPolyBookService;
+import io.americanexpress.synapse.service.rest.controller.BaseReadPolyController;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * {@code ReadPolyBookController} is the controller class for reading books in the Cassandra Book database.
+ */
+@RestController
+@RequestMapping(BookEndpoints.BOOK_ENDPOINT)
+public class ReadPolyBookController extends BaseReadPolyController<ReadBookPaginatedRequest, ReadBookResponse, ReadPolyBookService> {
+}

service/service-samples/sample-service-rest-cassandra-book/src/main/java/io/americanexpress/service/book/rest/model/ReadBookPaginatedRequest.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2020 American Express Travel Related Services Company, Inc.
+ *
+ * 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 io.americanexpress.service.book.rest.model;
+
+import io.americanexpress.synapse.service.rest.model.BasePaginatedServiceRequest;
+
+
+/**
+ * {@code ReadBookPaginatedRequest} is the request object for reading book paginated.
+ */
+public class ReadBookPaginatedRequest extends BasePaginatedServiceRequest {
+
+}

service/service-samples/sample-service-rest-cassandra-book/src/main/java/io/americanexpress/service/book/rest/service/ReadBookService.java

@@ -25,7 +25,7 @@
 import java.util.Optional;
 
 /**
- * {@code ReadBookService} is the service class for creating a book in the Cassandra Book database.
+ * {@code ReadBookService} is the service class for reading a book in the Cassandra Book database.
  */
 @Service
 public class ReadBookService extends BaseReadMonoService<ReadBookRequest, ReadBookResponse> {

service/service-samples/sample-service-rest-cassandra-book/src/main/java/io/americanexpress/service/book/rest/service/ReadPolyBookService.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright 2020 American Express Travel Related Services Company, Inc.
+ *
+ * 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 io.americanexpress.service.book.rest.service;
+
+import io.americanexpress.data.book.entity.BookEntity;
+import io.americanexpress.data.book.repository.BookRepository;
+import io.americanexpress.service.book.rest.model.ReadBookPaginatedRequest;
+import io.americanexpress.service.book.rest.model.ReadBookResponse;
+import io.americanexpress.service.book.rest.service.helper.ReadBookResponseCreator;
+import io.americanexpress.synapse.service.rest.model.PageInformation;
+import io.americanexpress.synapse.service.rest.service.BaseReadPolyService;
+import org.springframework.data.cassandra.core.query.CassandraPageRequest;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageImpl;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Slice;
+import org.springframework.http.HttpHeaders;
+import org.springframework.stereotype.Service;
+
+import java.nio.ByteBuffer;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * {@code ReadPolyBookService} is the service class for retrieving books from the Cassandra Book database.
+ */
+@Service
+public class ReadPolyBookService extends BaseReadPolyService<ReadBookPaginatedRequest, ReadBookResponse> {
+
+    private final BookRepository bookRepository;
+
+    private Map<PageInformation, ByteBuffer> pageInformationPagingStateMap = new HashMap<>();
+
+    /**
+     * Instantiates a new Read poly book service.
+     *
+     * @param bookRepository the book repository
+     */
+    public ReadPolyBookService(BookRepository bookRepository) {
+        this.bookRepository = bookRepository;
+    }
+
+    @Override
+    protected Page<ReadBookResponse> executeRead(HttpHeaders headers, ReadBookPaginatedRequest request) {
+        List<ReadBookResponse> readBookResponses;
+        if(request.getPageInformation() != null) {
+            Pageable pageable = PageRequest.of(0, request.getPageInformation().getSize());
+            Pageable cassandraPageable = CassandraPageRequest.of(pageable, getPageState(request.getPageInformation()));
+
+            Slice<BookEntity> bookEntitySlice = bookRepository.findAll(cassandraPageable);
+            addPageState(request.getPageInformation(), (CassandraPageRequest) bookEntitySlice.nextOrLastPageable());
+
+            readBookResponses = bookEntitySlice.getContent().stream().map(ReadBookResponseCreator::create).toList();
+        }else {
+            readBookResponses = bookRepository.findAll().stream().map(ReadBookResponseCreator::create).toList();
+        }
+        return new PageImpl<>(readBookResponses);
+    }
+
+    private ByteBuffer getPageState(PageInformation pageInformation) {
+        return pageInformationPagingStateMap.get(pageInformation);
+    }
+
+    private void addPageState(PageInformation pageInformation, CassandraPageRequest nextOrLastPageable) {
+        if(nextOrLastPageable.getPagingState() != null ) {
+            pageInformation.setPage(pageInformation.getPage() + 1);
+            pageInformationPagingStateMap.put(pageInformation, nextOrLastPageable.getPagingState());
+        }
+    }
+}

service/synapse-service-rest/src/main/java/io/americanexpress/synapse/service/rest/model/PageInformation.java

@@ -13,6 +13,8 @@
  */
 package io.americanexpress.synapse.service.rest.model;
 
+import java.util.Objects;
+
 /**
  * {@code PageInformation} class specifies the parameters for a service request,
  * limiting the results to a subset of how many (size) and on which page (page).
@@ -65,4 +67,17 @@ public int getSize() {
     public void setSize(int size) {
         this.size = size;
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        PageInformation that = (PageInformation) o;
+        return page == that.page && size == that.size;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(page, size);
+    }
 }