Add fine-grained HTTP error exceptions

core/src/main/java/feign/FeignException.java

@@ -75,7 +75,46 @@ public static FeignException errorStatus(String methodKey, Response response) {
     } catch (IOException ignored) { // NOPMD
     }
 
-    return new FeignException(response.status(), message, body);
+    return errorStatus(response.status(), message, body);
+  }
+
+  private static FeignException errorStatus(int status, String message, byte[] body) {
+    switch (status) {
+      case 400:
+        return new BadRequest(message, body);
+      case 401:
+        return new Unauthorized(message, body);
+      case 403:
+        return new Forbidden(message, body);
+      case 404:
+        return new NotFound(message, body);
+      case 405:
+        return new MethodNotAllowed(message, body);
+      case 406:
+        return new NotAcceptable(message, body);
+      case 409:
+        return new Conflict(message, body);
+      case 410:
+        return new Gone(message, body);
+      case 415:
+        return new UnsupportedMediaType(message, body);
+      case 429:
+        return new TooManyRequests(message, body);
+      case 422:
+        return new UnprocessableEntity(message, body);
+      case 500:
+        return new InternalServerError(message, body);
+      case 501:
+        return new NotImplemented(message, body);
+      case 502:
+        return new BadGateway(message, body);
+      case 503:
+        return new ServiceUnavailable(message, body);
+      case 504:
+        return new GatewayTimeout(message, body);
+      default:
+        return new FeignException(status, message, body);
+    }
   }
 
   static FeignException errorExecuting(Request request, IOException cause) {
@@ -85,4 +124,100 @@ static FeignException errorExecuting(Request request, IOException cause) {
         cause,
         null);
   }
+
+  public static class BadRequest extends FeignException {
+    public BadRequest(String message, byte[] body) {
+      super(400, message, body);
+    }
+  }
+
+  public static class Unauthorized extends FeignException {
+    public Unauthorized(String message, byte[] body) {
+      super(401, message, body);
+    }
+  }
+
+  public static class Forbidden extends FeignException {
+    public Forbidden(String message, byte[] body) {
+      super(403, message, body);
+    }
+  }
+
+  public static class NotFound extends FeignException {
+    public NotFound(String message, byte[] body) {
+      super(404, message, body);
+    }
+  }
+
+  public static class MethodNotAllowed extends FeignException {
+    public MethodNotAllowed(String message, byte[] body) {
+      super(405, message, body);
+    }
+  }
+
+  public static class NotAcceptable extends FeignException {
+    public NotAcceptable(String message, byte[] body) {
+      super(406, message, body);
+    }
+  }
+
+  public static class Conflict extends FeignException {
+    public Conflict(String message, byte[] body) {
+      super(409, message, body);
+    }
+  }
+
+  public static class Gone extends FeignException {
+    public Gone(String message, byte[] body) {
+      super(410, message, body);
+    }
+  }
+
+  public static class UnsupportedMediaType extends FeignException {
+    public UnsupportedMediaType(String message, byte[] body) {
+      super(415, message, body);
+    }
+  }
+
+  public static class TooManyRequests extends FeignException {
+    public TooManyRequests(String message, byte[] body) {
+      super(429, message, body);
+    }
+  }
+
+  public static class UnprocessableEntity extends FeignException {
+    public UnprocessableEntity(String message, byte[] body) {
+      super(422, message, body);
+    }
+  }
+
+  public static class InternalServerError extends FeignException {
+    public InternalServerError(String message, byte[] body) {
+      super(500, message, body);
+    }
+  }
+
+  public static class NotImplemented extends FeignException {
+    public NotImplemented(String message, byte[] body) {
+      super(501, message, body);
+    }
+  }
+
+  public static class BadGateway extends FeignException {
+    public BadGateway(String message, byte[] body) {
+      super(502, message, body);
+    }
+  }
+
+  public static class ServiceUnavailable extends FeignException {
+    public ServiceUnavailable(String message, byte[] body) {
+      super(503, message, body);
+    }
+  }
+
+  public static class GatewayTimeout extends FeignException {
+    public GatewayTimeout(String message, byte[] body) {
+      super(504, message, body);
+    }
+  }
 }

core/src/test/java/feign/FeignBuilderTest.java

@@ -130,6 +130,22 @@ public void testUrlPathConcatNoPathOnRequestLine() throws Exception {
     assertThat(server.takeRequest()).hasPath("/");
   }
 
+  @Test
+  public void testHttpNotFoundError() {
+    server.enqueue(new MockResponse().setResponseCode(404));
+
+    String url = "http://localhost:" + server.getPort() + "/";
+    TestInterface api = Feign.builder().target(TestInterface.class, url);
+
+    try {
+      api.getBodyAsString();
+      failBecauseExceptionWasNotThrown(FeignException.class);
+    } catch (FeignException.NotFound e) {
+      assertThat(e.status()).isEqualTo(404);
+    }
+
+  }
+
   @Test
   public void testUrlPathConcatNoInitialSlashOnPath() throws Exception {
     server.enqueue(new MockResponse().setBody("response data"));
@@ -433,6 +449,9 @@ interface TestInterface {
     @RequestLine("GET api/thing")
     Response getNoInitialSlashOnSlash();
 
+    @RequestLine("GET api/thing")
+    String getBodyAsString();
+
     @RequestLine(value = "GET /api/querymap/object")
     String queryMapEncoded(@QueryMap Object object);
 

core/src/test/java/feign/codec/DefaultErrorDecoderHttpErrorTest.java

@@ -0,0 +1,79 @@
+/**
+ * Copyright 2012-2018 The Feign Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package feign.codec;
+
+import feign.FeignException;
+import feign.Request;
+import feign.Request.HttpMethod;
+import feign.Response;
+import feign.Util;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import static org.assertj.core.api.Assertions.assertThat;
+
+@RunWith(Parameterized.class)
+public class DefaultErrorDecoderHttpErrorTest {
+
+  @Parameterized.Parameters(name = "error: [{0}], exception: [{1}]")
+  public static Object[][] errorCodes() {
+    return new Object[][] {
+        {400, FeignException.BadRequest.class},
+        {401, FeignException.Unauthorized.class},
+        {403, FeignException.Forbidden.class},
+        {404, FeignException.NotFound.class},
+        {405, FeignException.MethodNotAllowed.class},
+        {406, FeignException.NotAcceptable.class},
+        {409, FeignException.Conflict.class},
+        {429, FeignException.TooManyRequests.class},
+        {422, FeignException.UnprocessableEntity.class},
+        {500, FeignException.InternalServerError.class},
+        {501, FeignException.NotImplemented.class},
+        {502, FeignException.BadGateway.class},
+        {503, FeignException.ServiceUnavailable.class},
+        {504, FeignException.GatewayTimeout.class},
+        {599, FeignException.class},
+    };
+  }
+
+  @Parameterized.Parameter
+  public int httpStatus;
+
+  @Parameterized.Parameter(1)
+  public Class expectedExceptionClass;
+
+  private ErrorDecoder errorDecoder = new ErrorDecoder.Default();
+
+  private Map<String, Collection<String>> headers = new LinkedHashMap<>();
+
+  @Test
+  public void testExceptionIsHttpSpecific() throws Throwable {
+    Response response = Response.builder()
+        .status(httpStatus)
+        .reason("anything")
+        .request(Request.create(HttpMethod.GET, "/api", Collections.emptyMap(), null, Util.UTF_8))
+        .headers(headers)
+        .build();
+
+    Exception exception = errorDecoder.decode("Service#foo()", response);
+
+    assertThat(exception).isInstanceOf(expectedExceptionClass);
+    assertThat(((FeignException) exception).status()).isEqualTo(httpStatus);
+  }
+
+}