Merge pull request #10411 from Trixi-Turny/BAEL-4748

BAEL-4748 implement UserConsumerService with webClient and write Unit…

spring-5-reactive-client/src/main/java/com/baeldung/webclient/json/ReaderConsumerService.java

@@ -0,0 +1,18 @@
+package com.baeldung.webclient.json;
+
+import com.baeldung.webclient.json.model.Book;
+
+import java.util.List;
+
+public interface ReaderConsumerService {
+
+    List<Book> processReaderDataFromObjectArray();
+
+    List<Book> processReaderDataFromReaderArray();
+
+    List<Book> processReaderDataFromReaderList();
+
+    List<String> processNestedReaderDataFromReaderArray();
+
+    List<String> processNestedReaderDataFromReaderList();
+}

spring-5-reactive-client/src/main/java/com/baeldung/webclient/json/ReaderConsumerServiceImpl.java

@@ -0,0 +1,90 @@
+package com.baeldung.webclient.json;
+
+import com.baeldung.webclient.json.model.Book;
+import com.baeldung.webclient.json.model.Reader;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.http.MediaType;
+import org.springframework.web.reactive.function.client.WebClient;
+import reactor.core.publisher.Mono;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class ReaderConsumerServiceImpl implements ReaderConsumerService {
+
+    private final WebClient webClient;
+    private static final ObjectMapper mapper = new ObjectMapper();
+
+    public ReaderConsumerServiceImpl(WebClient webClient) {
+        this.webClient = webClient;
+    }
+    @Override
+    public List<Book> processReaderDataFromObjectArray() {
+        Mono<Object[]> response = webClient.get()
+          .accept(MediaType.APPLICATION_JSON)
+          .retrieve()
+          .bodyToMono(Object[].class).log();
+        Object[] objects = response.block();
+        return Arrays.stream(objects)
+          .map(object -> mapper.convertValue(object, Reader.class))
+          .map(Reader::getFavouriteBook)
+          .collect(Collectors.toList());
+    }
+
+    @Override
+    public List<Book> processReaderDataFromReaderArray() {
+        Mono<Reader[]> response =
+          webClient.get()
+          .accept(MediaType.APPLICATION_JSON)
+          .retrieve()
+          .bodyToMono(Reader[].class).log();
+
+        Reader[] readers = response.block();
+        return Arrays.stream(readers)
+          .map(Reader::getFavouriteBook)
+          .collect(Collectors.toList());
+    }
+
+    @Override
+    public List<Book> processReaderDataFromReaderList() {
+        Mono<List<Reader>> response = webClient.get()
+          .accept(MediaType.APPLICATION_JSON)
+          .retrieve()
+          .bodyToMono(new ParameterizedTypeReference<List<Reader>>() {});
+        List<Reader> readers = response.block();
+
+        return readers.stream()
+          .map(Reader::getFavouriteBook)
+          .collect(Collectors.toList());
+    }
+
+    @Override
+    public List<String> processNestedReaderDataFromReaderArray() {
+        Mono<Reader[]> response = webClient.get()
+          .accept(MediaType.APPLICATION_JSON)
+          .retrieve()
+          .bodyToMono(Reader[].class).log();
+        Reader[] readers = response.block();
+
+        return Arrays.stream(readers)
+          .flatMap(reader -> reader.getBooksRead().stream())
+          .map(Book::getAuthor)
+          .collect(Collectors.toList());
+    }
+
+    @Override
+    public List<String> processNestedReaderDataFromReaderList() {
+        Mono<List<Reader>> response = webClient.get()
+          .accept(MediaType.APPLICATION_JSON)
+          .retrieve()
+          .bodyToMono(new ParameterizedTypeReference<List<Reader>>() {});
+
+        List<Reader> readers = response.block();
+        return readers.stream()
+          .flatMap(reader -> reader.getBooksRead().stream())
+          .map(Book::getAuthor)
+          .collect(Collectors.toList());
+    }
+}

spring-5-reactive-client/src/main/java/com/baeldung/webclient/json/model/Book.java

@@ -0,0 +1,22 @@
+package com.baeldung.webclient.json.model;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+@JsonInclude(JsonInclude.Include.NON_NULL)
+public class Book {
+    private final String author;
+    private final String title;
+
+    @JsonCreator
+    public Book(
+            @JsonProperty("author") String author,
+            @JsonProperty("title") String title) {
+        this.author = author;
+        this.title  = title;
+    }
+    public String getAuthor() {
+        return this.author;
+    }
+}

spring-5-reactive-client/src/main/java/com/baeldung/webclient/json/model/Reader.java

@@ -0,0 +1,33 @@
+package com.baeldung.webclient.json.model;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import java.util.List;
+
+@JsonInclude(JsonInclude.Include.NON_NULL)
+public class Reader {
+    private final int id;
+    private final String name;
+    private final Book favouriteBook;
+    private final List<Book> booksRead;
+
+    @JsonCreator
+    public Reader(
+      @JsonProperty("id") int id,
+      @JsonProperty("name") String name,
+      @JsonProperty("favouriteBook") Book favouriteBook,
+      @JsonProperty("booksRead") List<Book> booksRead) {
+        this.id = id;
+        this.name = name;
+        this.favouriteBook = favouriteBook;
+        this.booksRead =booksRead;
+    }
+
+    public Book getFavouriteBook() {
+        return favouriteBook;
+    }
+
+    public List<Book> getBooksRead() { return booksRead; }
+}

spring-5-reactive-client/src/test/java/com/baeldung/webclient/json/ReaderConsumerServiceImplUnitTest.java

@@ -0,0 +1,88 @@
+package com.baeldung.webclient.json;
+
+import com.baeldung.webclient.json.model.Book;
+import org.junit.jupiter.api.Test;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.reactive.function.client.ClientResponse;
+import org.springframework.web.reactive.function.client.WebClient;
+import reactor.core.publisher.Mono;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.CoreMatchers.hasItems;
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.Matchers.hasProperty;
+
+public class ReaderConsumerServiceImplUnitTest {
+
+    private static String READER_JSON = "[{\"id\":1,\"name\":\"reader1\",\"favouriteBook\":{\"author\":\"Milan Kundera\",\"title\":\"The Unbearable Lightness of Being\"}," +
+      "\"booksRead\":[{\"author\":\"Charles Dickens\",\"title\":\"Oliver Twist\"},{\"author\":\"Milan Kundera\",\"title\":\"The Unbearable Lightness of Being\"}]}," +
+      "{\"id\":2,\"name\":\"reader2\",\"favouriteBook\":{\"author\":\"Douglas Adams\",\"title\":\"The Hitchhiker\'s Guide to the Galaxy\"}," +
+      "\"booksRead\":[{\"author\":\"J.R.R. Tolkien\",\"title\":\"Lord of the Rings\"}, " +
+      "{\"author\":\"Douglas Adams\",\"title\":\"The Hitchhiker\'s Guide to the Galaxy\"}]}]";
+
+    private static String BASE_URL = "http://localhost:8080/readers";
+
+    WebClient webClientMock = WebClient.builder().baseUrl(BASE_URL)
+      .exchangeFunction(clientRequest -> Mono.just(ClientResponse.create(HttpStatus.OK)
+        .header("content-type", "application/json")
+        .body(READER_JSON)
+        .build()))
+      .build();
+
+    private final ReaderConsumerService tested = new ReaderConsumerServiceImpl(webClientMock);
+
+    @Test
+    void when_processReaderDataFromObjectArray_then_OK() {
+        String expectedAuthor1 = "Milan Kundera";
+        String expectedAuthor2 = "Douglas Adams";
+        List<Book> actual = tested.processReaderDataFromObjectArray();
+        assertThat(actual, hasItems(hasProperty("author", is(expectedAuthor1)),
+          hasProperty("author", is(expectedAuthor2))));
+    }
+
+    @Test
+    void when_processReaderDataFromReaderArray_then_OK() {
+        String expectedAuthor1 = "Milan Kundera";
+        String expectedAuthor2 = "Douglas Adams";
+        List<Book> actual = tested.processReaderDataFromReaderArray();
+        assertThat(actual, hasItems(hasProperty("author", is(expectedAuthor1)),
+          hasProperty("author", is(expectedAuthor2))));
+    }
+
+    @Test
+    void when_processReaderDataFromReaderList_then_OK() {
+        String expectedAuthor1 = "Milan Kundera";
+        String expectedAuthor2 = "Douglas Adams";
+        List<Book> actual = tested.processReaderDataFromReaderList();
+        assertThat(actual, hasItems(hasProperty("author", is(expectedAuthor1)),
+          hasProperty("author", is(expectedAuthor2))));
+
+    }
+
+    @Test
+    void when_processNestedReaderDataFromReaderArray_then_OK() {
+        List<String> expected = Arrays.asList(
+          "Milan Kundera",
+          "Charles Dickens",
+          "J.R.R. Tolkien",
+          "Douglas Adams");
+
+        List<String> actual = tested.processNestedReaderDataFromReaderArray();
+        assertThat(actual, hasItems(expected.get(0), expected.get(1), expected.get(2), expected.get(3)));
+    }
+
+    @Test
+    void when_processNestedReaderDataFromReaderList_then_OK() {
+        List<String> expected = Arrays.asList(
+          "Milan Kundera",
+          "Charles Dickens",
+          "J.R.R. Tolkien",
+          "Douglas Adams");
+
+        List<String> actual = tested.processNestedReaderDataFromReaderList();
+        assertThat(actual, hasItems(expected.get(0), expected.get(1), expected.get(2), expected.get(3)));
+    }
+}