BAEL-6584: Added spring data reactive pagination along with tests (#14478)

* BAEL-6584: Added spring data reactive pagination along with tests

* BAEL-6584: removed unnecessary spaces

---------

Co-authored-by: balasr3 <balamurugan.radhakrishnan@imgarena.com>

spring-reactive-modules/pom.xml

@@ -18,6 +18,7 @@
 
     <modules>
         <module>spring-5-data-reactive</module>
+        <module>spring-5-data-reactive-2</module>
         <module>spring-5-reactive</module>
         <module>spring-5-reactive-2</module>
         <module>spring-5-reactive-3</module>

spring-reactive-modules/spring-5-data-reactive-2/README.md

@@ -0,0 +1,9 @@
+## Spring Data Reactive Project
+
+This module contains articles about reactive Spring 5 Data
+
+### The Course
+
+The "REST With Spring" Classes: http://bit.ly/restwithspring
+
+### Relevant Articles

spring-reactive-modules/spring-5-data-reactive-2/pom.xml

@@ -0,0 +1,77 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>spring-5-data-reactive-2</artifactId>
+    <name>spring-5-data-reactive-2</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.spring.reactive</groupId>
+        <artifactId>spring-reactive-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+
+    <properties>
+        <maven.compiler.source>8</maven.compiler.source>
+        <maven.compiler.target>8</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webflux</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-r2dbc</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-webflux</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.r2dbc</groupId>
+            <artifactId>r2dbc-h2</artifactId>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <optional>true</optional>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.projectreactor</groupId>
+            <artifactId>reactor-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>javax.validation</groupId>
+            <artifactId>validation-api</artifactId>
+            <version>2.0.1.Final</version>
+        </dependency>
+    </dependencies>
+
+</project>

spring-reactive-modules/spring-5-data-reactive-2/src/main/java/com/baeldung/pagination/PaginationApplication.java

@@ -0,0 +1,13 @@
+package com.baeldung.pagination;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class PaginationApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(PaginationApplication.class, args);
+    }
+
+}

spring-reactive-modules/spring-5-data-reactive-2/src/main/java/com/baeldung/pagination/config/CustomWebMvcConfigurationSupport.java

@@ -0,0 +1,32 @@
+package com.baeldung.pagination.config;
+
+import java.util.List;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.web.PageableHandlerMethodArgumentResolver;
+import org.springframework.data.web.SortHandlerMethodArgumentResolver;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;
+
+@Configuration
+public class CustomWebMvcConfigurationSupport extends WebMvcConfigurationSupport {
+
+    @Bean
+    public PageRequest defaultPageRequest() {
+        return PageRequest.of(0, 100);
+    }
+
+    @Override
+    protected void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
+        SortHandlerMethodArgumentResolver argumentResolver = new SortHandlerMethodArgumentResolver();
+        argumentResolver.setSortParameter("sort");
+        PageableHandlerMethodArgumentResolver resolver = new PageableHandlerMethodArgumentResolver(argumentResolver);
+        resolver.setFallbackPageable(defaultPageRequest());
+        resolver.setPageParameterName("page");
+        resolver.setSizeParameterName("size");
+        argumentResolvers.add(resolver);
+    }
+
+}

spring-reactive-modules/spring-5-data-reactive-2/src/main/java/com/baeldung/pagination/config/DatabaseConfig.java

@@ -0,0 +1,29 @@
+package com.baeldung.pagination.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.r2dbc.connection.init.CompositeDatabasePopulator;
+import org.springframework.r2dbc.connection.init.ConnectionFactoryInitializer;
+import org.springframework.r2dbc.connection.init.ResourceDatabasePopulator;
+
+import io.r2dbc.spi.ConnectionFactory;
+
+
+@Configuration
+public class DatabaseConfig {
+
+    @Bean
+    public ConnectionFactoryInitializer initializer(ConnectionFactory connectionFactory) {
+
+        ConnectionFactoryInitializer initializer = new ConnectionFactoryInitializer();
+        initializer.setConnectionFactory(connectionFactory);
+
+        CompositeDatabasePopulator populator = new CompositeDatabasePopulator();
+        populator.addPopulators(new ResourceDatabasePopulator(new ClassPathResource("init.sql")));
+        initializer.setDatabasePopulator(populator);
+
+        return initializer;
+    }
+
+}

spring-reactive-modules/spring-5-data-reactive-2/src/main/java/com/baeldung/pagination/controller/ProductPaginationController.java

@@ -0,0 +1,29 @@
+package com.baeldung.pagination.controller;
+
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageImpl;
+import org.springframework.data.domain.Pageable;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.pagination.model.Product;
+import com.baeldung.pagination.repository.ProductRepository;
+
+import lombok.RequiredArgsConstructor;
+import reactor.core.publisher.Mono;
+
+@RestController
+@RequiredArgsConstructor
+public class ProductPaginationController {
+
+    private final ProductRepository productRepository;
+
+    @GetMapping("/products")
+    public Mono<Page<Product>> findAllProducts(Pageable pageable) {
+        return this.productRepository.findAllBy(pageable)
+          .collectList()
+          .zipWith(this.productRepository.count())
+          .map(p -> new PageImpl<>(p.getT1(), pageable, p.getT2()));
+    }
+
+}

spring-reactive-modules/spring-5-data-reactive-2/src/main/java/com/baeldung/pagination/model/Product.java

@@ -0,0 +1,32 @@
+package com.baeldung.pagination.model;
+
+import java.util.UUID;
+
+import javax.validation.constraints.NotNull;
+import javax.validation.constraints.Size;
+
+import org.springframework.data.annotation.Id;
+import org.springframework.data.relational.core.mapping.Table;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@Table
+public class Product {
+
+    @Id
+    @Getter
+    private UUID id;
+
+    @NotNull
+    @Size(max = 255, message = "The property 'name' must be less than or equal to 255 characters.")
+    private String name;
+
+    @NotNull
+    private double price;
+}

spring-reactive-modules/spring-5-data-reactive-2/src/main/java/com/baeldung/pagination/repository/ProductRepository.java

@@ -0,0 +1,16 @@
+package com.baeldung.pagination.repository;
+
+import java.util.UUID;
+
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.repository.reactive.ReactiveSortingRepository;
+import org.springframework.stereotype.Repository;
+
+import com.baeldung.pagination.model.Product;
+
+import reactor.core.publisher.Flux;
+
+@Repository
+public interface ProductRepository extends ReactiveSortingRepository<Product, UUID> {
+    Flux<Product> findAllBy(Pageable pageable);
+}

spring-reactive-modules/spring-5-data-reactive-2/src/main/resources/init.sql

@@ -0,0 +1,15 @@
+create table product
+(
+    id UUID DEFAULT RANDOM_UUID() PRIMARY KEY,
+    name  varchar(50),
+    price decimal
+);
+
+insert into product(name, price)
+values ('product_A', 1.0);
+insert into product(name, price)
+values ('product_B', 2.0);
+insert into product(name, price)
+values ('product_C', 3.0);
+insert into product(name, price)
+values ('product_D', 4.0);

spring-reactive-modules/spring-5-data-reactive-2/src/test/java/com/baeldung/pagination/controller/ProductPaginationControllerIntegrationTest.java

@@ -0,0 +1,122 @@
+package com.baeldung.pagination.controller;
+
+import static org.assertj.core.api.Assertions.atIndex;
+import static org.assertj.core.api.AssertionsForClassTypes.tuple;
+import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.reactive.AutoConfigureWebTestClient;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.web.reactive.server.WebTestClient;
+
+import com.baeldung.pagination.model.Product;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+@AutoConfigureWebTestClient
+class ProductPaginationControllerIntegrationTest {
+
+    @Autowired
+    private WebTestClient webClient;
+
+    @Test
+    void WhenProductEndpointIsHit_thenShouldReturnProductsWithPagination() throws JsonProcessingException {
+        String response = webClient.get()
+            .uri("/products")
+            .exchange()
+            .expectStatus()
+            .is2xxSuccessful()
+            .expectBody(String.class)
+            .returnResult()
+            .getResponseBody();
+        Assertions.assertNotNull(response);
+
+        JsonNode pageResponse = new ObjectMapper().readValue(response, JsonNode.class);
+        Assertions.assertNotNull(pageResponse);
+        Assertions.assertEquals(4, pageResponse.get("totalElements")
+            .asInt());
+        Assertions.assertEquals(1, pageResponse.get("totalPages")
+            .asInt());
+        Assertions.assertTrue(pageResponse.get("last")
+            .asBoolean());
+        Assertions.assertTrue(pageResponse.get("first")
+            .asBoolean());
+        Assertions.assertEquals(100, pageResponse.get("size")
+            .asInt());
+        Assertions.assertEquals(4, pageResponse.get("numberOfElements")
+            .asInt());
+        Assertions.assertEquals(0, pageResponse.get("pageable")
+            .get("offset")
+            .asInt());
+        Assertions.assertEquals(0, pageResponse.get("pageable")
+            .get("pageNumber")
+            .asInt());
+        Assertions.assertEquals(100, pageResponse.get("pageable")
+            .get("pageSize")
+            .asInt());
+        Assertions.assertTrue(pageResponse.get("pageable")
+            .get("paged")
+            .asBoolean());
+        List<Product> content = new ObjectMapper().readValue(String.valueOf(pageResponse.get("content")), new TypeReference<List<Product>>() {
+        });
+        assertThat(content).hasSize(4);
+        assertThat(content).extracting("name", "price")
+            .contains(tuple("product_A", 1.0), atIndex(0))
+            .contains(tuple("product_B", 2.0), atIndex(1))
+            .contains(tuple("product_C", 3.0), atIndex(2))
+            .contains(tuple("product_D", 4.0), atIndex(3));
+    }
+
+    @Test
+    void WhenProductEndpointIsHitWithPageSizeAs2AndSortPriceByDesc_thenShouldReturnProductsWithPaginationIgnoring2Products() throws JsonProcessingException {
+        String response = webClient.get()
+            .uri("/products?page=1&size=2&sort=price,DESC")
+            .exchange()
+            .expectStatus()
+            .is2xxSuccessful()
+            .expectBody(String.class)
+            .returnResult()
+            .getResponseBody();
+        Assertions.assertNotNull(response);
+
+        JsonNode pageResponse = new ObjectMapper().readValue(response, JsonNode.class);
+        Assertions.assertNotNull(pageResponse);
+        Assertions.assertEquals(4, pageResponse.get("totalElements")
+            .asInt());
+        Assertions.assertEquals(2, pageResponse.get("totalPages")
+            .asInt());
+        Assertions.assertTrue(pageResponse.get("last")
+            .asBoolean());
+        Assertions.assertFalse(pageResponse.get("first")
+            .asBoolean());
+        Assertions.assertEquals(2, pageResponse.get("size")
+            .asInt());
+        Assertions.assertEquals(2, pageResponse.get("numberOfElements")
+            .asInt());
+        Assertions.assertEquals(2, pageResponse.get("pageable")
+            .get("offset")
+            .asInt());
+        Assertions.assertEquals(1, pageResponse.get("pageable")
+            .get("pageNumber")
+            .asInt());
+        Assertions.assertEquals(2, pageResponse.get("pageable")
+            .get("pageSize")
+            .asInt());
+        Assertions.assertTrue(pageResponse.get("pageable")
+            .get("paged")
+            .asBoolean());
+        List<Product> content = new ObjectMapper().readValue(String.valueOf(pageResponse.get("content")), new TypeReference<List<Product>>() {
+        });
+        assertThat(content).hasSize(2);
+        assertThat(content).extracting("name", "price")
+            .contains(tuple("product_B", 2.0), atIndex(0))
+            .contains(tuple("product_A", 1.0), atIndex(1));
+    }
+}