BAEL-4204 - Adding Interceptors in OkHTTP (#10539)

* 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

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

libraries-http-2/pom.xml

@@ -1,7 +1,7 @@
 <?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"
+    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">
+    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>libraries-http-2</artifactId>
     <name>libraries-http-2</name>
@@ -13,12 +13,17 @@
     </parent>
 
     <dependencies>
-         <!-- Dependencies for response decoder with okhttp -->
+        <!-- Dependencies for response decoder with okhttp -->
         <dependency>
             <groupId>com.squareup.okhttp3</groupId>
             <artifactId>okhttp</artifactId>
             <version>${okhttp.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.squareup.okhttp3</groupId>
+            <artifactId>logging-interceptor</artifactId>
+            <version>${okhttp.version}</version>
+        </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
@@ -81,9 +86,9 @@
     </dependencies>
 
     <properties>
-        <okhttp.version>3.14.2</okhttp.version>
+        <okhttp.version>4.9.1</okhttp.version>
         <gson.version>2.8.5</gson.version>
-        <mockwebserver.version>3.14.2</mockwebserver.version>
+        <mockwebserver.version>4.9.1</mockwebserver.version>
         <jetty.httpclient.version>1.0.3</jetty.httpclient.version>
         <jetty.server.version>9.4.19.v20190610</jetty.server.version>
         <rxjava2.version>2.2.11</rxjava2.version>

libraries-http-2/src/main/java/com/baeldung/okhttp/interceptors/CacheControlResponeInterceptor.java

@@ -0,0 +1,18 @@
+package com.baeldung.okhttp.interceptors;
+
+import java.io.IOException;
+
+import okhttp3.Interceptor;
+import okhttp3.Response;
+
+public class CacheControlResponeInterceptor implements Interceptor {
+
+    @Override
+    public Response intercept(Chain chain) throws IOException {
+        Response response = chain.proceed(chain.request());
+        return response.newBuilder()
+            .header("Cache-Control", "no-store")
+            .build();
+    }
+
+}

libraries-http-2/src/main/java/com/baeldung/okhttp/interceptors/ErrorMessage.java

@@ -0,0 +1,21 @@
+package com.baeldung.okhttp.interceptors;
+
+public class ErrorMessage {
+
+    private final int status;
+    private final String detail;
+
+    public ErrorMessage(int status, String detail) {
+        this.status = status;
+        this.detail = detail;
+    }
+
+    public int getStatus() {
+        return status;
+    }
+
+    public String getDetail() {
+        return detail;
+    }
+
+}

libraries-http-2/src/main/java/com/baeldung/okhttp/interceptors/ErrorResponseInterceptor.java

@@ -0,0 +1,32 @@
+package com.baeldung.okhttp.interceptors;
+
+import java.io.IOException;
+
+import com.google.gson.Gson;
+
+import okhttp3.Interceptor;
+import okhttp3.MediaType;
+import okhttp3.Response;
+import okhttp3.ResponseBody;
+
+public class ErrorResponseInterceptor implements Interceptor {
+    
+    public static final MediaType APPLICATION_JSON = MediaType.get("application/json; charset=utf-8");
+
+    @Override
+    public Response intercept(Chain chain) throws IOException {
+        Response response = chain.proceed(chain.request());
+        
+        if(!response.isSuccessful()) {
+            Gson gson = new Gson();
+            String body = gson.toJson(new ErrorMessage(response.code(), "The response from the server was not OK"));
+            ResponseBody responseBody = ResponseBody.create(body, APPLICATION_JSON);
+            
+            return response.newBuilder()
+                .body(responseBody)
+                .build();
+        }
+        return response;
+    }
+
+}

libraries-http-2/src/main/java/com/baeldung/okhttp/interceptors/SimpleLoggingInterceptor.java

@@ -0,0 +1,25 @@
+package com.baeldung.okhttp.interceptors;
+
+import java.io.IOException;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import okhttp3.Interceptor;
+import okhttp3.Request;
+import okhttp3.Response;
+
+public class SimpleLoggingInterceptor implements Interceptor {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(SimpleLoggingInterceptor.class);
+
+    @Override
+    public Response intercept(Chain chain) throws IOException {
+        Request request = chain.request();
+
+        LOGGER.info("Intercepted headers: {} from URL: {}", request.headers(), request.url());
+
+        return chain.proceed(request);
+    }
+
+}

libraries-http-2/src/test/java/com/baeldung/okhttp/interceptors/InterceptorIntegrationTest.java

@@ -0,0 +1,90 @@
+package com.baeldung.okhttp.interceptors;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.IOException;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.Response;
+import okhttp3.logging.HttpLoggingInterceptor;
+import okhttp3.logging.HttpLoggingInterceptor.Level;
+import okhttp3.mockwebserver.MockResponse;
+import okhttp3.mockwebserver.MockWebServer;
+
+public class InterceptorIntegrationTest {
+
+    @Rule
+    public MockWebServer server = new MockWebServer();
+
+    @Test
+    public void givenSimpleLogginInterceptor_whenRequestSent_thenHeadersLogged() throws IOException {
+        server.enqueue(new MockResponse().setBody("Hello Baeldung Readers!"));
+        
+        OkHttpClient client = new OkHttpClient.Builder()
+            .addNetworkInterceptor(new SimpleLoggingInterceptor())
+            .build();
+
+        Request request = new Request.Builder()
+            .url(server.url("/greeting"))
+            .header("User-Agent", "A Baeldung Reader")
+            .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
+    public void givenResponseInterceptor_whenRequestSent_thenCacheControlSetToNoStore() throws IOException {
+        server.enqueue(new MockResponse().setBody("Hello Baeldung Readers!"));
+        
+        OkHttpClient client = new OkHttpClient.Builder()
+            .addInterceptor(getHttpLogger())
+            .addInterceptor(new CacheControlResponeInterceptor())
+            .build();
+
+        Request request = new Request.Builder()
+            .url(server.url("/greeting"))
+            .header("User-Agent", "A Baeldung Reader")
+            .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());
+            assertEquals("Response cache-control should be", "no-store", response.header("Cache-Control"));
+        }
+    }
+    
+    @Test
+    public void givenErrorResponseInterceptor_whenResponseIs500_thenBodyIsJsonWithStatus() throws IOException {
+        server.enqueue(new MockResponse().setResponseCode(500).setBody("Hello Baeldung Readers!"));
+        
+        OkHttpClient client = new OkHttpClient.Builder()
+            .addInterceptor(getHttpLogger())
+            .addInterceptor(new ErrorResponseInterceptor())
+            .build();
+
+        Request request = new Request.Builder()
+            .url(server.url("/greeting"))
+            .header("User-Agent", "A Baeldung Reader")
+            .build();
+
+        try (Response response = client.newCall(request).execute()) {
+            assertEquals("Response code should be: ", 500, response.code());
+            assertEquals("Body should be: ", "{\"status\":500,\"detail\":\"The response from the server was not OK\"}", 
+                response.body().string());
+        }
+    }
+
+    private HttpLoggingInterceptor getHttpLogger() {
+        HttpLoggingInterceptor logger = new HttpLoggingInterceptor();
+        logger.setLevel(Level.HEADERS);
+        return logger;
+    }
+
+}