Add client-side exception hierarchy

The `WebClient` has a new exception hierarchy: * `WebClientException` is the root of all exceptions thrown by the `WebClient` * `WebClientResponseException` are all exceptions associated with specific HTTP response status codes * `WebClientErrorException` and `WebServerErrorException` are respectively for 4xx and 5xx HTTP status codes `ResponseExtractor` implementations are adapted to optionally throw exceptions if it's impossible to extract the relevant parts of the response (e.g. extracting the response body if the response is a 404). This commit also introduces `ResponseErrorHandler`s that take care of the whole exception mapping infrastructure. Since `WebClientResponseException`s provide the status, headers and response body, we also need a dedicated mechanism to extract information from the response body at that level. The `BodyExtractors` are responsible for extracting that information from the exception, given they are provided with all the information they need; in that case, message decoders are required. To convey all this new information downstream, the `WebClient` now wraps the message converters and response error handler instances into a dedicated `WebClientConfig` object.
2016-07-17 14:40:33 +02:00
parent fe79219607
commit 7a0c2422c6
20 changed files with 1056 additions and 194 deletions
--- a/spring-web/src/test/java/org/springframework/http/MockHttpOutputMessage.java
+++ b/spring-web/src/test/java/org/springframework/http/MockHttpOutputMessage.java
@@ -45,7 +45,7 @@ public class MockHttpOutputMessage implements HttpOutputMessage {

 	/**
 	 * Return a copy of the actual headers written at the time of the call to
-	 * getBody, i.e. ignoring any further changes that may have been made to
+	 * getResponseBody, i.e. ignoring any further changes that may have been made to
 	 * the underlying headers, e.g. via a previously obtained instance.
 	 */
 	public HttpHeaders getWrittenHeaders() {
--- a/spring-web/src/test/java/org/springframework/web/client/reactive/DefaultResponseErrorHandlerTests.java
+++ b/spring-web/src/test/java/org/springframework/web/client/reactive/DefaultResponseErrorHandlerTests.java
@@ -0,0 +1,99 @@
+package org.springframework.web.client.reactive;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+import static org.mockito.BDDMockito.*;
+import static org.mockito.Mockito.mock;
+import static org.springframework.web.client.reactive.ResponseExtractors.*;
+
+import java.util.Collections;
+import java.util.List;
+
+import org.junit.Before;
+import org.junit.Test;
+import reactor.core.publisher.Flux;
+import reactor.test.TestSubscriber;
+
+import org.springframework.core.codec.StringDecoder;
+import org.springframework.core.codec.StringEncoder;
+import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.core.io.buffer.DefaultDataBufferFactory;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.client.reactive.ClientHttpResponse;
+import org.springframework.http.converter.reactive.CodecHttpMessageConverter;
+import org.springframework.http.converter.reactive.HttpMessageConverter;
+
+/**
+ * Unit tests for {@link DefaultResponseErrorHandler}.
+ *
+ * @author Brian Clozel
+ */
+public class DefaultResponseErrorHandlerTests {
+
+	private DefaultResponseErrorHandler errorHandler;
+
+	private ClientHttpResponse response;
+
+	private List<HttpMessageConverter<?>> messageConverters;
+
+	@Before
+	public void setUp() throws Exception {
+		this.errorHandler = new DefaultResponseErrorHandler();
+		this.response = mock(ClientHttpResponse.class);
+		this.messageConverters = Collections
+				.singletonList(new CodecHttpMessageConverter<>(new StringEncoder(), new StringDecoder()));
+	}
+
+	@Test
+	public void noError() throws Exception {
+		given(this.response.getStatusCode()).willReturn(HttpStatus.OK);
+		this.errorHandler.handleError(this.response, this.messageConverters);
+	}
+
+	@Test
+	public void clientError() throws Exception {
+		HttpHeaders headers = new HttpHeaders();
+		headers.setContentType(MediaType.TEXT_PLAIN);
+		DataBuffer buffer = new DefaultDataBufferFactory().allocateBuffer();
+		buffer.write(new String("Page Not Found").getBytes("UTF-8"));
+		given(this.response.getStatusCode()).willReturn(HttpStatus.NOT_FOUND);
+		given(this.response.getHeaders()).willReturn(headers);
+		given(this.response.getBody()).willReturn(Flux.just(buffer));
+		try {
+			this.errorHandler.handleError(this.response, this.messageConverters);
+			fail("expected HttpClientErrorException");
+		}
+		catch (WebClientErrorException exc) {
+			assertThat(exc.getMessage(), is("404 Not Found"));
+			assertThat(exc.getStatus(), is(HttpStatus.NOT_FOUND));
+			TestSubscriber.subscribe(exc.getResponseBody(as(String.class)))
+					.awaitAndAssertNextValues("Page Not Found")
+					.assertComplete();
+		}
+	}
+
+	@Test
+	public void serverError() throws Exception {
+		HttpHeaders headers = new HttpHeaders();
+		headers.setContentType(MediaType.TEXT_PLAIN);
+		DataBuffer buffer = new DefaultDataBufferFactory().allocateBuffer();
+		buffer.write(new String("Internal Server Error").getBytes("UTF-8"));
+		given(this.response.getStatusCode()).willReturn(HttpStatus.INTERNAL_SERVER_ERROR);
+		given(this.response.getHeaders()).willReturn(headers);
+		given(this.response.getBody()).willReturn(Flux.just(buffer));
+		try {
+			this.errorHandler.handleError(this.response, this.messageConverters);
+			fail("expected HttpServerErrorException");
+		}
+		catch (WebServerErrorException exc) {
+			assertThat(exc.getMessage(), is("500 Internal Server Error"));
+			assertThat(exc.getStatus(), is(HttpStatus.INTERNAL_SERVER_ERROR));
+			TestSubscriber.subscribe(exc.getResponseBody(as(String.class)))
+					.awaitAndAssertNextValues("Internal Server Error")
+					.assertComplete();
+		}
+	}
+
+}
--- a/spring-web/src/test/java/org/springframework/web/client/reactive/ResponseExtractorsTests.java
+++ b/spring-web/src/test/java/org/springframework/web/client/reactive/ResponseExtractorsTests.java
@@ -0,0 +1,209 @@
+package org.springframework.web.client.reactive;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+import static org.mockito.BDDMockito.eq;
+import static org.mockito.BDDMockito.*;
+import static org.mockito.Mockito.mock;
+
+import java.io.UnsupportedEncodingException;
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.Before;
+import org.junit.Test;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.test.TestSubscriber;
+import reactor.core.Exceptions;
+
+import org.springframework.core.codec.StringDecoder;
+import org.springframework.core.codec.StringEncoder;
+import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.core.io.buffer.DefaultDataBufferFactory;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.http.client.reactive.ClientHttpResponse;
+import org.springframework.http.codec.json.JacksonJsonDecoder;
+import org.springframework.http.codec.json.JacksonJsonEncoder;
+import org.springframework.http.converter.reactive.CodecHttpMessageConverter;
+import org.springframework.http.converter.reactive.HttpMessageConverter;
+
+/**
+ * Unit tests for {@link ResponseExtractors}.
+ *
+ * @author Brian Clozel
+ */
+public class ResponseExtractorsTests {
+
+	private HttpHeaders headers = new HttpHeaders();
+
+	private ClientHttpResponse response;
+
+	private List<HttpMessageConverter<?>> messageConverters;
+
+	private WebClientConfig webClientConfig;
+
+	private ResponseErrorHandler errorHandler;
+
+	@Before
+	public void setup() throws Exception {
+		this.headers = new HttpHeaders();
+		this.response = mock(ClientHttpResponse.class);
+		given(this.response.getHeaders()).willReturn(headers);
+		this.messageConverters = Arrays.asList(
+				new CodecHttpMessageConverter<>(new StringEncoder(), new StringDecoder()),
+				new CodecHttpMessageConverter<>(new JacksonJsonEncoder(), new JacksonJsonDecoder()));
+		this.webClientConfig = mock(WebClientConfig.class);
+		this.errorHandler = mock(ResponseErrorHandler.class);
+		given(this.webClientConfig.getMessageConverters()).willReturn(this.messageConverters);
+		given(this.webClientConfig.getResponseErrorHandler()).willReturn(this.errorHandler);
+	}
+
+	@Test
+	public void shouldExtractResponseEntityMono() throws Exception {
+		this.headers.setContentType(MediaType.TEXT_PLAIN);
+		given(this.response.getStatusCode()).willReturn(HttpStatus.OK);
+		given(this.response.getBody()).willReturn(createFluxBody("test content"));
+
+		Mono<ResponseEntity<String>> result = ResponseExtractors.response(String.class)
+				.extract(Mono.just(this.response), this.webClientConfig);
+
+		TestSubscriber.subscribe(result)
+				.awaitAndAssertNextValuesWith(entity -> {
+					assertThat(entity.getStatusCode(), is(HttpStatus.OK));
+					assertThat(entity.getHeaders().getContentType(), is(MediaType.TEXT_PLAIN));
+					assertThat(entity.getBody(), is("test content"));
+				})
+				.assertComplete();
+	}
+
+	@Test
+	public void shouldExtractResponseEntityFlux() throws Exception {
+		this.headers.setContentType(MediaType.TEXT_PLAIN);
+		given(this.response.getStatusCode()).willReturn(HttpStatus.OK);
+		given(this.response.getBody()).willReturn(createFluxBody("test", " content"));
+
+		Mono<ResponseEntity<String>> result = ResponseExtractors.response(String.class)
+				.extract(Mono.just(this.response), this.webClientConfig);
+
+		TestSubscriber.subscribe(result)
+				.awaitAndAssertNextValuesWith(entity -> {
+					assertThat(entity.getStatusCode(), is(HttpStatus.OK));
+					assertThat(entity.getHeaders().getContentType(), is(MediaType.TEXT_PLAIN));
+					assertThat(entity.getBody(), is("test content"));
+				})
+				.assertComplete();
+	}
+
+	@Test
+	public void shouldExtractResponseEntityWithEmptyBody() throws Exception {
+		given(this.response.getStatusCode()).willReturn(HttpStatus.NO_CONTENT);
+		given(this.response.getBody()).willReturn(Flux.empty());
+
+		Mono<ResponseEntity<String>> result = ResponseExtractors.response(String.class)
+				.extract(Mono.just(this.response), this.webClientConfig);
+
+		TestSubscriber.subscribe(result)
+				.awaitAndAssertNextValuesWith(entity -> {
+					assertThat(entity.getStatusCode(), is(HttpStatus.NO_CONTENT));
+					assertNull(entity.getBody());
+				})
+				.assertComplete();
+	}
+
+	@Test
+	public void shouldExtractResponseEntityAsStream() throws Exception {
+		this.headers.setContentType(MediaType.TEXT_PLAIN);
+		given(this.response.getStatusCode()).willReturn(HttpStatus.OK);
+		given(this.response.getBody()).willReturn(createFluxBody("test", " content"));
+
+		Mono<ResponseEntity<Flux<String>>> result = ResponseExtractors.responseStream(String.class)
+				.extract(Mono.just(this.response), this.webClientConfig);
+
+		TestSubscriber.subscribe(result)
+				.awaitAndAssertNextValuesWith(entity -> {
+					assertThat(entity.getStatusCode(), is(HttpStatus.OK));
+					assertThat(entity.getHeaders().getContentType(), is(MediaType.TEXT_PLAIN));
+					TestSubscriber.subscribe(entity.getBody())
+							.awaitAndAssertNextValues("test", " content")
+							.assertComplete();
+				})
+				.assertComplete();
+	}
+
+	@Test
+	public void shouldGetErrorWhenExtractingWithMissingConverter() throws Exception {
+		this.headers.setContentType(MediaType.APPLICATION_XML);
+		given(this.response.getStatusCode()).willReturn(HttpStatus.OK);
+		given(this.response.getBody()).willReturn(createFluxBody("test content"));
+
+		Mono<ResponseEntity<SomePojo>> result = ResponseExtractors.response(SomePojo.class)
+				.extract(Mono.just(this.response), this.webClientConfig);
+
+		TestSubscriber.subscribe(result)
+				.assertErrorWith(t -> {
+					assertThat(t, instanceOf(WebClientException.class));
+					WebClientException exc = (WebClientException) t;
+					assertThat(exc.getMessage(), containsString("Could not decode response body of type 'application/xml'"));
+					assertThat(exc.getMessage(), containsString("$SomePojo"));
+				});
+	}
+
+	@Test
+	public void shouldExtractResponseHeaders() throws Exception {
+		this.headers.setContentType(MediaType.TEXT_PLAIN);
+		this.headers.setETag("\"Spring\"");
+		given(this.response.getStatusCode()).willReturn(HttpStatus.OK);
+
+		Mono<HttpHeaders> result = ResponseExtractors.headers()
+				.extract(Mono.just(this.response), this.webClientConfig);
+
+		TestSubscriber.subscribe(result)
+				.awaitAndAssertNextValuesWith(headers -> {
+					assertThat(headers.getContentType(), is(MediaType.TEXT_PLAIN));
+					assertThat(headers.getETag(), is("\"Spring\""));
+				})
+				.assertComplete();
+	}
+
+	@Test
+	public void shouldExecuteResponseHandler() throws Exception {
+		this.headers.setContentType(MediaType.TEXT_PLAIN);
+		given(this.response.getStatusCode()).willReturn(HttpStatus.NOT_FOUND);
+		given(this.response.getBody()).willReturn(createFluxBody("test", " content"));
+
+		Mono<String> result = ResponseExtractors.body(String.class)
+				.extract(Mono.just(this.response), this.webClientConfig);
+
+		TestSubscriber.subscribe(result)
+				.assertValueCount(1)
+				.assertComplete();
+
+		then(this.errorHandler).should().handleError(eq(this.response), eq(this.messageConverters));
+	}
+
+
+	private Flux<DataBuffer> createFluxBody(String... items) throws Exception {
+
+		DefaultDataBufferFactory factory = new DefaultDataBufferFactory();
+		return Flux.just(items)
+				.map(item -> {
+					DataBuffer buffer = factory.allocateBuffer();
+					try {
+						buffer.write(new String(item).getBytes("UTF-8"));
+					}
+					catch (UnsupportedEncodingException exc) {
+						Exceptions.propagate(exc);
+					}
+					return buffer;
+				});
+	}
+
+	protected class SomePojo {
+		public String foo;
+	}
+
+}
--- a/spring-web/src/test/java/org/springframework/web/client/reactive/RxJava1WebClientIntegrationTests.java
+++ b/spring-web/src/test/java/org/springframework/web/client/reactive/RxJava1WebClientIntegrationTests.java
@@ -28,9 +28,7 @@ import okhttp3.mockwebserver.MockWebServer;
 import okhttp3.mockwebserver.RecordedRequest;
 import org.hamcrest.Matchers;
 import org.junit.After;
-import org.junit.Assert;
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 import rx.Observable;
 import rx.Single;
@@ -43,7 +41,7 @@ import org.springframework.http.client.reactive.ReactorClientHttpConnector;
 import org.springframework.http.codec.Pojo;

 /**
- * {@link WebClient} integration tests with the {@code Obserable} and {@code Single} API.
+ * {@link WebClient} integration tests with the {@code Observable} and {@code Single} API.
 *
 * @author Brian Clozel
 */
@@ -80,9 +78,9 @@ public class RxJava1WebClientIntegrationTests {
 		ts.assertCompleted();

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("*/*", request.getHeader(HttpHeaders.ACCEPT));
-		Assert.assertEquals("/greeting?name=Spring", request.getPath());
+		assertEquals(1, server.getRequestCount());
+		assertEquals("*/*", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals("/greeting?name=Spring", request.getPath());
 	}

 	@Test
@@ -106,10 +104,10 @@ public class RxJava1WebClientIntegrationTests {
 		ts.assertCompleted();

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("testvalue", request.getHeader("X-Test-Header"));
-		Assert.assertEquals("*/*", request.getHeader(HttpHeaders.ACCEPT));
-		Assert.assertEquals("/greeting?name=Spring", request.getPath());
+		assertEquals(1, server.getRequestCount());
+		assertEquals("testvalue", request.getHeader("X-Test-Header"));
+		assertEquals("*/*", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals("/greeting?name=Spring", request.getPath());
 	}

 	@Test
@@ -135,9 +133,9 @@ public class RxJava1WebClientIntegrationTests {
 		ts.assertCompleted();

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("/greeting?name=Spring", request.getPath());
-		Assert.assertEquals("text/plain", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals(1, server.getRequestCount());
+		assertEquals("/greeting?name=Spring", request.getPath());
+		assertEquals("text/plain", request.getHeader(HttpHeaders.ACCEPT));
 	}

 	@Test
@@ -163,9 +161,9 @@ public class RxJava1WebClientIntegrationTests {
 		ts.assertCompleted();

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("/json", request.getPath());
-		Assert.assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals(1, server.getRequestCount());
+		assertEquals("/json", request.getPath());
+		assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
 	}

 	@Test
@@ -190,9 +188,9 @@ public class RxJava1WebClientIntegrationTests {
 		ts.assertCompleted();

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("/pojo", request.getPath());
-		Assert.assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals(1, server.getRequestCount());
+		assertEquals("/pojo", request.getPath());
+		assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
 	}

 	@Test
@@ -217,9 +215,9 @@ public class RxJava1WebClientIntegrationTests {
 		ts.assertCompleted();

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("/pojos", request.getPath());
-		Assert.assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals(1, server.getRequestCount());
+		assertEquals("/pojos", request.getPath());
+		assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
 	}

 	@Test
@@ -245,9 +243,9 @@ public class RxJava1WebClientIntegrationTests {
 		ts.assertCompleted();

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("/pojos", request.getPath());
-		Assert.assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals(1, server.getRequestCount());
+		assertEquals("/pojos", request.getPath());
+		assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
 	}

 	@Test
@@ -275,12 +273,12 @@ public class RxJava1WebClientIntegrationTests {
 		ts.assertCompleted();

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("/pojo/capitalize", request.getPath());
-		Assert.assertEquals("{\"foo\":\"foofoo\",\"bar\":\"barbar\"}", request.getBody().readUtf8());
-		Assert.assertEquals("chunked", request.getHeader(HttpHeaders.TRANSFER_ENCODING));
-		Assert.assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
-		Assert.assertEquals("application/json", request.getHeader(HttpHeaders.CONTENT_TYPE));
+		assertEquals(1, server.getRequestCount());
+		assertEquals("/pojo/capitalize", request.getPath());
+		assertEquals("{\"foo\":\"foofoo\",\"bar\":\"barbar\"}", request.getBody().readUtf8());
+		assertEquals("chunked", request.getHeader(HttpHeaders.TRANSFER_ENCODING));
+		assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals("application/json", request.getHeader(HttpHeaders.CONTENT_TYPE));
 	}

 	@Test
@@ -304,33 +302,35 @@ public class RxJava1WebClientIntegrationTests {
 		ts.assertCompleted();

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("/test", request.getPath());
-		Assert.assertEquals("testkey=testvalue", request.getHeader(HttpHeaders.COOKIE));
+		assertEquals(1, server.getRequestCount());
+		assertEquals("/test", request.getPath());
+		assertEquals("testkey=testvalue", request.getHeader(HttpHeaders.COOKIE));
 	}

 	@Test
-	@Ignore
 	public void shouldGetErrorWhen404() throws Exception {

 		HttpUrl baseUrl = server.url("/greeting?name=Spring");
-		this.server.enqueue(new MockResponse().setResponseCode(404));
+		this.server.enqueue(new MockResponse().setResponseCode(404)
+				.setHeader("Content-Type", "text/plain").setBody("Not Found"));

 		Single<String> result = this.webClient
 				.perform(get(baseUrl.toString()))
 				.extract(body(String.class));

-		// TODO: error message should be converted to a ClientException
 		TestSubscriber<String> ts = new TestSubscriber<String>();
 		result.subscribe(ts);
 		ts.awaitTerminalEvent(2, TimeUnit.SECONDS);

-		ts.assertError(WebClientException.class);
+		ts.assertError(WebClientErrorException.class);
+		WebClientErrorException exc = (WebClientErrorException) ts.getOnErrorEvents().get(0);
+		assertEquals(404, exc.getStatus().value());
+		assertEquals(MediaType.TEXT_PLAIN, exc.getResponseHeaders().getContentType());

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("*/*", request.getHeader(HttpHeaders.ACCEPT));
-		Assert.assertEquals("/greeting?name=Spring", request.getPath());
+		assertEquals(1, server.getRequestCount());
+		assertEquals("*/*", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals("/greeting?name=Spring", request.getPath());
 	}

 	@After
--- a/spring-web/src/test/java/org/springframework/web/client/reactive/WebClientIntegrationTests.java
+++ b/spring-web/src/test/java/org/springframework/web/client/reactive/WebClientIntegrationTests.java
@@ -28,18 +28,17 @@ import okhttp3.mockwebserver.MockWebServer;
 import okhttp3.mockwebserver.RecordedRequest;
 import org.hamcrest.Matchers;
 import org.junit.After;
-import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.test.TestSubscriber;

-import org.springframework.http.codec.Pojo;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.client.reactive.ReactorClientHttpConnector;
+import org.springframework.http.codec.Pojo;

 /**
 * {@link WebClient} integration tests with the {@code Flux} and {@code Mono} API.
@@ -71,16 +70,16 @@ public class WebClientIntegrationTests {
 		TestSubscriber
 				.subscribe(result)
 				.awaitAndAssertNextValuesWith(
-					httpHeaders -> {
-						assertEquals(MediaType.TEXT_PLAIN, httpHeaders.getContentType());
-						assertEquals(13L, httpHeaders.getContentLength());
-					})
+						httpHeaders -> {
+							assertEquals(MediaType.TEXT_PLAIN, httpHeaders.getContentType());
+							assertEquals(13L, httpHeaders.getContentLength());
+						})
 				.assertComplete();

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("*/*", request.getHeader(HttpHeaders.ACCEPT));
-		Assert.assertEquals("/greeting?name=Spring", request.getPath());
+		assertEquals(1, server.getRequestCount());
+		assertEquals("*/*", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals("/greeting?name=Spring", request.getPath());
 	}

 	@Test
@@ -101,10 +100,10 @@ public class WebClientIntegrationTests {
 				.assertComplete();

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("testvalue", request.getHeader("X-Test-Header"));
-		Assert.assertEquals("*/*", request.getHeader(HttpHeaders.ACCEPT));
-		Assert.assertEquals("/greeting?name=Spring", request.getPath());
+		assertEquals(1, server.getRequestCount());
+		assertEquals("testvalue", request.getHeader("X-Test-Header"));
+		assertEquals("*/*", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals("/greeting?name=Spring", request.getPath());
 	}

 	@Test
@@ -124,11 +123,11 @@ public class WebClientIntegrationTests {
 					assertEquals(200, response.getStatusCode().value());
 					assertEquals(MediaType.TEXT_PLAIN, response.getHeaders().getContentType());
 					assertEquals("Hello Spring!", response.getBody());
-		});
+				});
 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("/greeting?name=Spring", request.getPath());
-		Assert.assertEquals("text/plain", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals(1, server.getRequestCount());
+		assertEquals("/greeting?name=Spring", request.getPath());
+		assertEquals("text/plain", request.getHeader(HttpHeaders.ACCEPT));
 	}

 	@Test
@@ -149,9 +148,9 @@ public class WebClientIntegrationTests {
 				.awaitAndAssertNextValues(content)
 				.assertComplete();
 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("/json", request.getPath());
-		Assert.assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals(1, server.getRequestCount());
+		assertEquals("/json", request.getPath());
+		assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
 	}

 	@Test
@@ -171,9 +170,9 @@ public class WebClientIntegrationTests {
 				.awaitAndAssertNextValuesWith(p -> assertEquals("barbar", p.getBar()))
 				.assertComplete();
 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("/pojo", request.getPath());
-		Assert.assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals(1, server.getRequestCount());
+		assertEquals("/pojo", request.getPath());
+		assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
 	}

 	@Test
@@ -191,14 +190,14 @@ public class WebClientIntegrationTests {
 		TestSubscriber
 				.subscribe(result)
 				.awaitAndAssertNextValuesWith(
-					p -> assertThat(p.getBar(), Matchers.is("bar1")),
-					p -> assertThat(p.getBar(), Matchers.is("bar2")))
+						p -> assertThat(p.getBar(), Matchers.is("bar1")),
+						p -> assertThat(p.getBar(), Matchers.is("bar2")))
 				.assertValueCount(2)
 				.assertComplete();
 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("/pojos", request.getPath());
-		Assert.assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals(1, server.getRequestCount());
+		assertEquals("/pojos", request.getPath());
+		assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
 	}

 	@Test
@@ -216,15 +215,15 @@ public class WebClientIntegrationTests {
 		TestSubscriber
 				.subscribe(result)
 				.awaitAndAssertNextValuesWith(
-					response -> {
-						assertEquals(200, response.getStatusCode().value());
-						assertEquals(MediaType.APPLICATION_JSON, response.getHeaders().getContentType());
-					})
+						response -> {
+							assertEquals(200, response.getStatusCode().value());
+							assertEquals(MediaType.APPLICATION_JSON, response.getHeaders().getContentType());
+						})
 				.assertComplete();
 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("/pojos", request.getPath());
-		Assert.assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals(1, server.getRequestCount());
+		assertEquals("/pojos", request.getPath());
+		assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
 	}

 	@Test
@@ -249,12 +248,12 @@ public class WebClientIntegrationTests {
 				.assertComplete();

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("/pojo/capitalize", request.getPath());
-		Assert.assertEquals("{\"foo\":\"foofoo\",\"bar\":\"barbar\"}", request.getBody().readUtf8());
-		Assert.assertEquals("chunked", request.getHeader(HttpHeaders.TRANSFER_ENCODING));
-		Assert.assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
-		Assert.assertEquals("application/json", request.getHeader(HttpHeaders.CONTENT_TYPE));
+		assertEquals(1, server.getRequestCount());
+		assertEquals("/pojo/capitalize", request.getPath());
+		assertEquals("{\"foo\":\"foofoo\",\"bar\":\"barbar\"}", request.getBody().readUtf8());
+		assertEquals("chunked", request.getHeader(HttpHeaders.TRANSFER_ENCODING));
+		assertEquals("application/json", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals("application/json", request.getHeader(HttpHeaders.CONTENT_TYPE));
 	}

 	@Test
@@ -274,16 +273,17 @@ public class WebClientIntegrationTests {
 				.assertComplete();

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("/test", request.getPath());
-		Assert.assertEquals("testkey=testvalue", request.getHeader(HttpHeaders.COOKIE));
+		assertEquals(1, server.getRequestCount());
+		assertEquals("/test", request.getPath());
+		assertEquals("testkey=testvalue", request.getHeader(HttpHeaders.COOKIE));
 	}

 	@Test
 	public void shouldGetErrorWhen404() throws Exception {

 		HttpUrl baseUrl = server.url("/greeting?name=Spring");
-		this.server.enqueue(new MockResponse().setResponseCode(404));
+		this.server.enqueue(new MockResponse().setResponseCode(404)
+				.setHeader("Content-Type", "text/plain").setBody("Not Found"));

 		Mono<String> result = this.webClient
 				.perform(get(baseUrl.toString()))
@@ -292,12 +292,50 @@ public class WebClientIntegrationTests {
 		TestSubscriber
 				.subscribe(result)
 				.await()
-				.assertError();
+				.assertErrorWith(t -> {
+					assertThat(t, Matchers.instanceOf(WebClientErrorException.class));
+					WebClientErrorException exc = (WebClientErrorException) t;
+					assertEquals(404, exc.getStatus().value());
+					assertEquals(MediaType.TEXT_PLAIN, exc.getResponseHeaders().getContentType());
+
+					Mono<String> body = exc.getResponseBody(as(String.class));
+
+					TestSubscriber.subscribe(body)
+							.awaitAndAssertNextValues("Not Found")
+							.assertComplete();
+				});

 		RecordedRequest request = server.takeRequest();
-		Assert.assertEquals(1, server.getRequestCount());
-		Assert.assertEquals("*/*", request.getHeader(HttpHeaders.ACCEPT));
-		Assert.assertEquals("/greeting?name=Spring", request.getPath());
+		assertEquals(1, server.getRequestCount());
+		assertEquals("*/*", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals("/greeting?name=Spring", request.getPath());
+	}
+
+	@Test
+	public void shouldGetErrorWhen500() throws Exception {
+
+		HttpUrl baseUrl = server.url("/greeting?name=Spring");
+		this.server.enqueue(new MockResponse().setResponseCode(500)
+				.setHeader("Content-Type", "text/plain").setBody("Server Error"));
+
+		Mono<String> result = this.webClient
+				.perform(get(baseUrl.toString()))
+				.extract(body(String.class));
+
+		TestSubscriber
+				.subscribe(result)
+				.await()
+				.assertErrorWith(t -> {
+					assertThat(t, Matchers.instanceOf(WebServerErrorException.class));
+					WebServerErrorException exc = (WebServerErrorException) t;
+					assertEquals(500, exc.getStatus().value());
+					assertEquals(MediaType.TEXT_PLAIN, exc.getResponseHeaders().getContentType());
+				});
+
+		RecordedRequest request = server.takeRequest();
+		assertEquals(1, server.getRequestCount());
+		assertEquals("*/*", request.getHeader(HttpHeaders.ACCEPT));
+		assertEquals("/greeting?name=Spring", request.getPath());
 	}

 	@After