BAEL-4205 - A Guide to Events in OkHTTP (#10734)

* BAEL-4706 - Spring Boot with Spring Batch

* BAEL-3948 - Fix test(s) in spring-batch which leaves repository.sqlite
changed

* BAEL-4736 - Convert JSONArray to List of Object using camel-jackson

* BAEL-4756 - Mockito MockSettings

* BAEL-4756 - Mockito MockSettings - fix spelling

* BAEL-2674 - Upgrade the Okhttp article

* BAEL-4204 - Adding Interceptors in OkHTTP

* BAEL-4836 - Mocking Static Methods with Mockito

* BAEL-4205 - A Guide to Events in OkHTTP

Co-authored-by: Jonathan Cook <jcook@sciops.esa.int>

libraries-http-2/src/main/java/com/baeldung/okhttp/events/EventTimer.java

@@ -0,0 +1,156 @@
+package com.baeldung.okhttp.events;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.Proxy;
+import java.util.List;
+
+import okhttp3.Call;
+import okhttp3.Connection;
+import okhttp3.EventListener;
+import okhttp3.Handshake;
+import okhttp3.HttpUrl;
+import okhttp3.Protocol;
+import okhttp3.Request;
+import okhttp3.Response;
+
+public class EventTimer extends EventListener {
+
+    private long start;
+
+    private void logTimedEvent(String name) {
+        long now = System.nanoTime();
+        if (name.equals("callStart")) {
+            start = now;
+        }
+        long elapsedNanos = now - start;
+        System.out.printf("%.3f %s%n", elapsedNanos / 1000000000d, name);
+    }
+
+    @Override
+    public void callStart(Call call) {
+        logTimedEvent("callStart");
+    }
+
+    @Override
+    public void proxySelectStart(Call call, HttpUrl url) {
+        logTimedEvent("proxySelectStart");
+    }
+
+    @Override
+    public void proxySelectEnd(Call call, HttpUrl url, List<Proxy> proxies) {
+        logTimedEvent("proxySelectEnd");
+    }
+
+    @Override
+    public void dnsStart(Call call, String domainName) {
+        logTimedEvent("dnsStart");
+    }
+
+    @Override
+    public void dnsEnd(Call call, String domainName, List<InetAddress> inetAddressList) {
+        logTimedEvent("dnsEnd");
+    }
+
+    @Override
+    public void connectStart(Call call, InetSocketAddress inetSocketAddress, Proxy proxy) {
+        logTimedEvent("connectStart");
+    }
+
+    @Override
+    public void secureConnectStart(Call call) {
+        logTimedEvent("secureConnectStart");
+    }
+
+    @Override
+    public void secureConnectEnd(Call call, Handshake handshake) {
+        logTimedEvent("secureConnectEnd");
+    }
+
+    @Override
+    public void connectEnd(Call call, InetSocketAddress inetSocketAddress, Proxy proxy, Protocol protocol) {
+        logTimedEvent("connectEnd");
+    }
+
+    @Override
+    public void connectFailed(Call call, InetSocketAddress inetSocketAddress, Proxy proxy, Protocol protocol, IOException ioe) {
+        logTimedEvent("connectFailed");
+    }
+
+    @Override
+    public void connectionAcquired(Call call, Connection connection) {
+        logTimedEvent("connectionAcquired");
+    }
+
+    @Override
+    public void connectionReleased(Call call, Connection connection) {
+        logTimedEvent("connectionReleased");
+    }
+
+    @Override
+    public void requestHeadersStart(Call call) {
+        logTimedEvent("requestHeadersStart");
+    }
+
+    @Override
+    public void requestHeadersEnd(Call call, Request request) {
+        logTimedEvent("requestHeadersEnd");
+    }
+
+    @Override
+    public void requestBodyStart(Call call) {
+        logTimedEvent("requestBodyStart");
+    }
+
+    @Override
+    public void requestBodyEnd(Call call, long byteCount) {
+        logTimedEvent("requestBodyEnd");
+    }
+
+    @Override
+    public void requestFailed(Call call, IOException ioe) {
+        logTimedEvent("requestFailed");
+    }
+
+    @Override
+    public void responseHeadersStart(Call call) {
+        logTimedEvent("responseHeadersStart");
+    }
+
+    @Override
+    public void responseHeadersEnd(Call call, Response response) {
+        logTimedEvent("responseHeadersEnd");
+    }
+
+    @Override
+    public void responseBodyStart(Call call) {
+        logTimedEvent("responseBodyStart");
+    }
+
+    @Override
+    public void responseBodyEnd(Call call, long byteCount) {
+        logTimedEvent("responseBodyEnd");
+    }
+
+    @Override
+    public void responseFailed(Call call, IOException ioe) {
+        logTimedEvent("responseFailed");
+    }
+
+    @Override
+    public void callEnd(Call call) {
+        logTimedEvent("callEnd");
+    }
+
+    @Override
+    public void callFailed(Call call, IOException ioe) {
+        logTimedEvent("callFailed");
+    }
+
+    @Override
+    public void canceled(Call call) {
+        logTimedEvent("canceled");
+    }
+
+}

libraries-http-2/src/main/java/com/baeldung/okhttp/events/SimpleLogEventsListener.java

@@ -0,0 +1,37 @@
+package com.baeldung.okhttp.events;
+
+import java.time.LocalDateTime;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import okhttp3.Call;
+import okhttp3.EventListener;
+import okhttp3.Request;
+import okhttp3.Response;
+
+public class SimpleLogEventsListener extends EventListener {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(SimpleLogEventsListener.class);
+
+    @Override
+    public void callStart(Call call) {
+        LOGGER.info("callStart at {}", LocalDateTime.now());
+    }
+
+    @Override
+    public void requestHeadersEnd(Call call, Request request) {
+        LOGGER.info("requestHeadersEnd at {} with headers {}", LocalDateTime.now(), request.headers());
+    }
+
+    @Override
+    public void responseHeadersEnd(Call call, Response response) {
+        LOGGER.info("responseHeadersEnd at {} with headers {}", LocalDateTime.now(), response.headers());
+    }
+
+    @Override
+    public void callEnd(Call call) {
+        LOGGER.info("callEnd at {}", LocalDateTime.now());
+    }
+
+}

libraries-http-2/src/test/java/com/baeldung/okhttp/events/EventTimerLiveTest.java

@@ -0,0 +1,31 @@
+package com.baeldung.okhttp.events;
+
+import static org.junit.Assert.*;
+
+import java.io.IOException;
+
+import org.junit.Test;
+
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.Response;
+
+public class EventTimerLiveTest {
+
+    @Test
+    public void givenSimpleEventTimer_whenRequestSent_thenCallsLogged() throws IOException {
+        
+        OkHttpClient client = new OkHttpClient.Builder()
+            .eventListener(new EventTimer())
+            .build();
+
+        Request request = new Request.Builder()
+            .url("https://www.baeldung.com/")
+            .build();
+
+        try (Response response = client.newCall(request).execute()) {
+            assertEquals("Response code should be: ", 200, response.code());
+        }
+    }
+
+}

libraries-http-2/src/test/java/com/baeldung/okhttp/events/LogEventsListenerIntegrationTest.java

@@ -0,0 +1,53 @@
+package com.baeldung.okhttp.events;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.IOException;
+import java.net.SocketTimeoutException;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.Response;
+import okhttp3.mockwebserver.MockResponse;
+import okhttp3.mockwebserver.MockWebServer;
+
+public class LogEventsListenerIntegrationTest {
+    
+    @Rule
+    public MockWebServer server = new MockWebServer();
+
+    @Test
+    public void givenSimpleEventLogger_whenRequestSent_thenCallsLogged() throws IOException {
+        server.enqueue(new MockResponse().setBody("Hello Baeldung Readers!"));
+        
+        OkHttpClient client = new OkHttpClient.Builder()
+            .eventListener(new SimpleLogEventsListener())
+            .build();
+
+        Request request = new Request.Builder()
+            .url(server.url("/"))
+            .build();
+
+        try (Response response = client.newCall(request).execute()) {
+            assertEquals("Response code should be: ", 200, response.code());
+            assertEquals("Body should be: ", "Hello Baeldung Readers!", response.body().string());
+        }
+    }
+    
+    @Test (expected = SocketTimeoutException.class)
+    public void givenConnectionError_whenRequestSent_thenFailedCallsLogged() throws IOException {
+        OkHttpClient client = new OkHttpClient.Builder()
+            .eventListener(new EventTimer())
+            .build();
+
+        Request request = new Request.Builder()
+            .url(server.url("/"))
+            .build();
+
+        client.newCall(request).execute();
+    }
+
+}