#BAEL-2802:

Implement response decoder for ok http client and apply review notes

libraries-2/pom.xml

@@ -55,6 +55,33 @@
 			<artifactId>spring-boot-starter</artifactId>
 			<version>${spring-boot-starter.version}</version>
 		</dependency>
+
+		<!-- Dependencies for response decoder with okhttp -->
+		<dependency>
+			<groupId>com.squareup.okhttp3</groupId>
+			<artifactId>okhttp</artifactId>
+			<version>3.14.2</version>
+		</dependency>
+
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-databind</artifactId>
+			<version>2.9.9</version>
+		</dependency>
+
+		<dependency>
+			<groupId>com.google.code.gson</groupId>
+			<artifactId>gson</artifactId>
+			<version>2.8.5</version>
+		</dependency>
+
+		<dependency>
+			<groupId>com.squareup.okhttp3</groupId>
+			<artifactId>mockwebserver</artifactId>
+			<version>3.14.2</version>
+			<scope>test</scope>
+		</dependency>
+
 	</dependencies>
 
 	<properties>

libraries-2/src/test/java/com/baeldung/okhttp/ResponseDecoderUnitTest.java

@@ -0,0 +1,160 @@
+package com.baeldung.okhttp;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.gson.Gson;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.ResponseBody;
+import okhttp3.mockwebserver.MockResponse;
+import okhttp3.mockwebserver.MockWebServer;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+import java.io.InputStreamReader;
+
+public class ResponseDecoderUnitTest {
+
+    @Rule
+    public ExpectedException exceptionRule = ExpectedException.none();
+
+    @Rule
+    public MockWebServer server = new MockWebServer();
+
+    SimpleEntity sampleResponse;
+
+    MockResponse mockResponse;
+
+    OkHttpClient client;
+
+
+    @Before
+    public void setUp() {
+        sampleResponse = new SimpleEntity("Baeldung");
+        client = new OkHttpClient.Builder()
+                .build();
+        mockResponse = new MockResponse()
+                .setResponseCode(200)
+                .setHeader("Content-Type", "application/json")
+                .setBody(new Gson().toJson(sampleResponse));
+    }
+
+    @Test
+    public void givenJacksonDecoder_whenGetByteStreamOfResponse_thenExpectSimpleEntity() throws Exception {
+
+        server.enqueue(mockResponse);
+
+        Request request = new Request.Builder()
+                .url(server.url(""))
+                .build();
+        ResponseBody responseBody = client.newCall(request).execute().body();
+
+        Assert.assertNotNull(responseBody);
+        Assert.assertNotEquals(0, responseBody.contentLength());
+
+        ObjectMapper objectMapper = new ObjectMapper();
+        SimpleEntity response = objectMapper.readValue(responseBody.byteStream()
+                , SimpleEntity.class);
+
+        Assert.assertEquals(sampleResponse.getName(), response.getName());
+    }
+
+    @Test
+    public void givenJacksonDecoder_whenGetStringOfResponse_thenExpectSimpleEntity() throws Exception {
+
+        server.enqueue(mockResponse);
+
+        Request request = new Request.Builder()
+                .url(server.url(""))
+                .build();
+        ResponseBody responseBody = client.newCall(request).execute().body();
+
+        Assert.assertNotNull(responseBody);
+        Assert.assertNotEquals(0, responseBody.contentLength());
+
+        ObjectMapper objectMapper = new ObjectMapper();
+        SimpleEntity response = objectMapper.readValue(responseBody.string(), SimpleEntity.class);
+
+        Assert.assertEquals(sampleResponse.getName(), response.getName());
+    }
+
+    @Test
+    public void givenJacksonDecoder_whenGetCharStreamOfResponse_thenExpectSimpleEntity() throws Exception {
+
+        server.enqueue(mockResponse);
+
+        Request request = new Request.Builder()
+                .url(server.url(""))
+                .build();
+        ResponseBody responseBody = client.newCall(request).execute().body();
+
+        Assert.assertNotNull(responseBody);
+        Assert.assertNotEquals(0, responseBody.contentLength());
+
+        ObjectMapper objectMapper = new ObjectMapper();
+        SimpleEntity response = objectMapper.readValue(responseBody.charStream(), SimpleEntity.class);
+
+        Assert.assertEquals(sampleResponse.getName(), response.getName());
+    }
+
+    @Test
+    public void givenGsonDecoder_whenGetByteStreamOfResponse_thenExpectSimpleEntity() throws Exception {
+
+        server.enqueue(mockResponse);
+
+        Request request = new Request.Builder()
+                .url(server.url(""))
+                .build();
+        ResponseBody responseBody = client.newCall(request).execute().body();
+
+        Assert.assertNotNull(responseBody);
+        Assert.assertNotEquals(0, responseBody.contentLength());
+
+        Gson gson = new Gson();
+        SimpleEntity response = gson.fromJson(new InputStreamReader(responseBody.byteStream())
+                , SimpleEntity.class);
+
+        Assert.assertEquals(sampleResponse.getName(), response.getName());
+    }
+
+    @Test
+    public void givenGsonDecoder_whenGetStringOfResponse_thenExpectSimpleEntity() throws Exception {
+
+        server.enqueue(mockResponse);
+
+        Request request = new Request.Builder()
+                .url(server.url(""))
+                .build();
+        ResponseBody responseBody = client.newCall(request).execute().body();
+
+        Assert.assertNotNull(responseBody);
+
+        Gson gson = new Gson();
+        SimpleEntity response = gson.fromJson(responseBody.string(), SimpleEntity.class);
+
+        Assert.assertEquals(sampleResponse.getName(), response.getName());
+    }
+
+    @Test
+    public void givenGsonDecoder_whenGetCharStreamOfResponse_thenExpectSimpleEntity() throws Exception {
+
+        server.enqueue(mockResponse);
+
+        Request request = new Request.Builder()
+                .url(server.url(""))
+                .build();
+
+        ResponseBody responseBody = client.newCall(request).execute().body();
+
+        Assert.assertNotNull(responseBody);
+
+        Gson gson = new Gson();
+        SimpleEntity response = gson.fromJson(responseBody.charStream(), SimpleEntity.class);
+
+        Assert.assertEquals(sampleResponse.getName(), response.getName());
+    }
+
+
+}

libraries-2/src/test/java/com/baeldung/okhttp/SimpleEntity.java

@@ -0,0 +1,21 @@
+package com.baeldung.okhttp;
+
+public class SimpleEntity {
+    protected String name;
+
+    public SimpleEntity(String name) {
+        this.name = name;
+    }
+
+    //no-arg constructor, getters and setters here
+    public SimpleEntity() {
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+}