Add Problem handling

CHANGELOG.md

@@ -9,6 +9,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 ### Added
 
 - More typedeclarations
+- Improved error responses: the body contains a `Problem` (JSON) with details about the exception;
+  using the metasvc-client the `Problem`-object can be retrieved from the exception by calling `getProblem()`
 
 ## [9.0.0](https://github.com/dbmdz/metadata-service/releases/tag/9.0.0) – 2024-03-14
 

metasvc-client/pom.xml

@@ -6,7 +6,7 @@
   <parent>
     <groupId>io.github.dbmdz.metadata</groupId>
     <artifactId>metasvc</artifactId>
-    <version>9.0.1-SNAPSHOT</version>
+    <version>9.1.0-SNAPSHOT</version>
   </parent>
 
   <name>Metadata-Service: Repository Client</name>

metasvc-client/src/main/java/de/digitalcollections/client/BaseRestClient.java

@@ -266,10 +266,8 @@ protected PageResponse<T> doGetRequestForPagedObjectList(
       String requestUrl, PageRequest pageRequest) throws TechnicalException {
     if (!requestUrl.contains("?")) {
       requestUrl = requestUrl + "?";
-    } else {
-      if (!requestUrl.endsWith("&")) {
-        requestUrl = requestUrl + "&";
-      }
+    } else if (!requestUrl.endsWith("&")) {
+      requestUrl = requestUrl + "&";
     }
     String findParams = getFindParamsAsString(pageRequest);
     requestUrl = requestUrl + findParams;

metasvc-client/src/main/java/de/digitalcollections/cudami/client/CudamiRestClient.java

@@ -12,13 +12,10 @@
 import java.util.Map;
 import java.util.UUID;
 import java.util.stream.Collectors;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 public class CudamiRestClient<T extends UniqueObject> extends BaseRestClient<T> {
 
   public static final String API_VERSION_PREFIX = "/v6";
-  private static final Logger LOGGER = LoggerFactory.getLogger(CudamiRestClient.class);
 
   public CudamiRestClient(
       HttpClient http,

metasvc-lobid-client/pom.xml

@@ -7,7 +7,7 @@
   <parent>
     <groupId>io.github.dbmdz.metadata</groupId>
     <artifactId>metasvc</artifactId>
-    <version>9.0.1-SNAPSHOT</version>
+    <version>9.1.0-SNAPSHOT</version>
   </parent>
 
   <name>Metadata-Service: lobid.org Client</name>

metasvc-model/pom.xml

@@ -6,7 +6,7 @@
   <parent>
     <groupId>io.github.dbmdz.metadata</groupId>
     <artifactId>metasvc</artifactId>
-    <version>9.0.1-SNAPSHOT</version>
+    <version>9.1.0-SNAPSHOT</version>
   </parent>
 
   <name>Metadata-Service: Model</name>
@@ -102,5 +102,15 @@
       <artifactId>wdtk-datamodel</artifactId>
       <version>0.14.7</version>
     </dependency>
+    <dependency>
+      <groupId>org.zalando</groupId>
+      <artifactId>problem</artifactId>
+      <version>0.26.0</version>
+    </dependency>
+    <dependency>
+      <groupId>org.zalando</groupId>
+      <artifactId>jackson-datatype-problem</artifactId>
+      <version>0.26.0</version>
+    </dependency>
   </dependencies>
 </project>

metasvc-model/src/main/java/de/digitalcollections/model/exception/http/HttpErrorDecoder.java

@@ -1,5 +1,6 @@
 package de.digitalcollections.model.exception.http;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
 import de.digitalcollections.model.exception.http.client.ForbiddenException;
 import de.digitalcollections.model.exception.http.client.HttpClientException;
 import de.digitalcollections.model.exception.http.client.ImATeapotException;
@@ -13,74 +14,110 @@
 import de.digitalcollections.model.exception.http.server.HttpVersionNotSupportedException;
 import de.digitalcollections.model.exception.http.server.NotImplementedException;
 import de.digitalcollections.model.exception.http.server.ServiceUnavailableException;
+import de.digitalcollections.model.jackson.DigitalCollectionsObjectMapper;
 import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
+import java.nio.charset.StandardCharsets;
+import java.util.Optional;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.zalando.problem.Problem;
+import org.zalando.problem.jackson.ProblemModule;
 
 public class HttpErrorDecoder {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(HttpErrorDecoder.class);
+  private static final ObjectMapper mapper;
+
+  static {
+    mapper = new DigitalCollectionsObjectMapper().registerModule(new ProblemModule());
+  }
 
   private static HttpException clientException(
-      String methodKey, int statusCode, String requestUrl) {
+      String methodKey, int statusCode, String requestUrl, Problem problem) {
     switch (statusCode) {
       case 401:
-        return new UnauthorizedException(methodKey, statusCode, requestUrl);
+        return new UnauthorizedException(methodKey, statusCode, requestUrl, problem);
       case 403:
-        return new ForbiddenException(methodKey, statusCode, requestUrl);
+        return new ForbiddenException(methodKey, statusCode, requestUrl, problem);
       case 404:
-        return new ResourceNotFoundException(methodKey, statusCode, requestUrl);
+        return new ResourceNotFoundException(methodKey, statusCode, requestUrl, problem);
       case 418:
-        return new ImATeapotException(methodKey, statusCode, requestUrl);
+        return new ImATeapotException(methodKey, statusCode, requestUrl, problem);
       case 422:
-        return new UnprocessableEntityException(methodKey, statusCode, requestUrl);
+        return new UnprocessableEntityException(methodKey, statusCode, requestUrl, problem);
       case 451:
-        return new UnavailableForLegalReasonsException(methodKey, statusCode, requestUrl);
+        return new UnavailableForLegalReasonsException(methodKey, statusCode, requestUrl, problem);
       default:
-        return new HttpClientException(methodKey, statusCode, requestUrl);
+        return new HttpClientException(methodKey, statusCode, requestUrl, problem);
     }
   }
 
   public static HttpException decode(String methodKey, int statusCode, HttpResponse response) {
     String requestUrl = null;
-    try {
-      if (response != null) {
-        requestUrl = response.request().uri().toURL().toString();
+    Problem problem = null;
+    if (response != null) {
+      requestUrl =
+          Optional.ofNullable(response.request())
+              .map(HttpRequest::uri)
+              .map(
+                  uri -> {
+                    try {
+                      return uri.toURL();
+                    } catch (MalformedURLException e) {
+                      LOGGER.warn("Invalid request URL for: " + uri.toString());
+                      return null;
+                    }
+                  })
+              .map(URL::toString)
+              .orElse(null);
+
+      final byte[] body = (byte[]) response.body();
+      if (body != null && body.length > 0) {
+        try {
+          problem = mapper.readerFor(Problem.class).readValue(body);
+        } catch (Exception e) {
+          LOGGER.error(
+              "Got response="
+                  + new String(body, StandardCharsets.UTF_8)
+                  + " but cannot construct problem: "
+                  + e,
+              e);
+        }
       }
-    } catch (MalformedURLException ex) {
-      LOGGER.warn("Invalid request Url for: " + response.request().uri());
     }
 
     if (400 <= statusCode && statusCode < 500) {
-      return clientException(methodKey, statusCode, requestUrl);
+      return clientException(methodKey, statusCode, requestUrl, problem);
     } else if (500 <= statusCode && statusCode < 600) {
-      return serverException(methodKey, statusCode, requestUrl);
+      return serverException(methodKey, statusCode, requestUrl, problem);
     } else {
-      return genericHttpException(methodKey, statusCode, requestUrl);
+      return genericHttpException(methodKey, statusCode, requestUrl, problem);
     }
   }
 
   private static HttpException genericHttpException(
-      String methodKey, int statusCode, String requestUrl) {
-    return new HttpException(methodKey, statusCode, requestUrl);
+      String methodKey, int statusCode, String requestUrl, Problem problem) {
+    return new HttpException(methodKey, statusCode, requestUrl, problem);
   }
 
   private static HttpServerException serverException(
-      String methodKey, int statusCode, String requestUrl) {
+      String methodKey, int statusCode, String requestUrl, Problem problem) {
     switch (statusCode) {
       case 501:
-        return new NotImplementedException(methodKey, statusCode, requestUrl);
+        return new NotImplementedException(methodKey, statusCode, requestUrl, problem);
       case 502:
-        return new BadGatewayException(methodKey, statusCode, requestUrl);
+        return new BadGatewayException(methodKey, statusCode, requestUrl, problem);
       case 503:
-        return new ServiceUnavailableException(methodKey, statusCode, requestUrl);
+        return new ServiceUnavailableException(methodKey, statusCode, requestUrl, problem);
       case 504:
-        return new GatewayTimeOutException(methodKey, statusCode, requestUrl);
+        return new GatewayTimeOutException(methodKey, statusCode, requestUrl, problem);
       case 505:
-        return new HttpVersionNotSupportedException(methodKey, statusCode, requestUrl);
+        return new HttpVersionNotSupportedException(methodKey, statusCode, requestUrl, problem);
       default:
-        return new HttpServerException(methodKey, statusCode, requestUrl);
+        return new HttpServerException(methodKey, statusCode, requestUrl, problem);
     }
   }
 }

metasvc-model/src/main/java/de/digitalcollections/model/exception/http/HttpException.java

@@ -1,30 +1,36 @@
 package de.digitalcollections.model.exception.http;
 
+import org.zalando.problem.Problem;
+
 public class HttpException extends RuntimeException {
 
   private final String methodKey;
   private final String request;
   private final Integer statuscode;
+  private final Problem problem;
 
   public HttpException(String methodKey, Exception ex) {
     super(String.format("Got exception for backend call %s.", methodKey), ex);
     this.methodKey = methodKey;
     this.request = null;
     this.statuscode = null;
+    this.problem = null;
   }
 
   public HttpException(String methodKey, int statuscode) {
     super(String.format("Got status code %d for backend call %s.", statuscode, methodKey));
     this.methodKey = methodKey;
     this.request = null;
     this.statuscode = statuscode;
+    this.problem = null;
   }
 
-  public HttpException(String methodKey, int statuscode, String request) {
+  public HttpException(String methodKey, int statuscode, String request, Problem problem) {
     super(String.format("Got %d for backend call %s.%n⤷ %s", statuscode, methodKey, request));
     this.methodKey = methodKey;
     this.request = request;
     this.statuscode = statuscode;
+    this.problem = problem;
   }
 
   public String getMethodKey() {
@@ -38,4 +44,8 @@ public String getRequest() {
   public Integer getStatusCode() {
     return statuscode;
   }
+
+  public Problem getProblem() {
+    return problem;
+  }
 }

metasvc-model/src/main/java/de/digitalcollections/model/exception/http/client/ForbiddenException.java

@@ -1,8 +1,10 @@
 package de.digitalcollections.model.exception.http.client;
 
+import org.zalando.problem.Problem;
+
 public class ForbiddenException extends HttpClientException {
 
-  public ForbiddenException(String methodKey, int status, String request) {
-    super(methodKey, status, request);
+  public ForbiddenException(String methodKey, int status, String request, Problem problem) {
+    super(methodKey, status, request, problem);
   }
 }

metasvc-model/src/main/java/de/digitalcollections/model/exception/http/client/HttpClientException.java

@@ -1,10 +1,11 @@
 package de.digitalcollections.model.exception.http.client;
 
 import de.digitalcollections.model.exception.http.HttpException;
+import org.zalando.problem.Problem;
 
 public class HttpClientException extends HttpException {
 
-  public HttpClientException(String methodKey, int status, String request) {
-    super(methodKey, status, request);
+  public HttpClientException(String methodKey, int status, String request, Problem problem) {
+    super(methodKey, status, request, problem);
   }
 }

metasvc-model/src/main/java/de/digitalcollections/model/exception/http/client/ImATeapotException.java

@@ -1,13 +1,15 @@
 package de.digitalcollections.model.exception.http.client;
 
+import org.zalando.problem.Problem;
+
 /**
  * HttpStatusCode 418 denoting the api is wrongfully using a teapot for making coffee as specified
  * in the Hyper Text Coffee Pot Control Protocol (see <a
  * href="https://tools.ietf.org/html/rfc2324">RFC 2324</a> for details).
  */
 public class ImATeapotException extends HttpClientException {
 
-  public ImATeapotException(String methodKey, int status, String request) {
-    super(methodKey, status, request);
+  public ImATeapotException(String methodKey, int status, String request, Problem problem) {
+    super(methodKey, status, request, problem);
   }
 }

metasvc-model/src/main/java/de/digitalcollections/model/exception/http/client/ResourceNotFoundException.java

@@ -1,8 +1,14 @@
 package de.digitalcollections.model.exception.http.client;
 
+import org.zalando.problem.Problem;
+
 public class ResourceNotFoundException extends HttpClientException {
 
+  public ResourceNotFoundException(String methodKey, int status, String request, Problem problem) {
+    super(methodKey, status, request, problem);
+  }
+
   public ResourceNotFoundException(String methodKey, int status, String request) {
-    super(methodKey, status, request);
+    this(methodKey, status, request, null);
   }
 }

metasvc-model/src/main/java/de/digitalcollections/model/exception/http/client/UnauthorizedException.java

@@ -1,8 +1,10 @@
 package de.digitalcollections.model.exception.http.client;
 
+import org.zalando.problem.Problem;
+
 public class UnauthorizedException extends HttpClientException {
 
-  public UnauthorizedException(String methodKey, int status, String request) {
-    super(methodKey, status, request);
+  public UnauthorizedException(String methodKey, int status, String request, Problem problem) {
+    super(methodKey, status, request, problem);
   }
 }

metasvc-model/src/main/java/de/digitalcollections/model/exception/http/client/UnavailableForLegalReasonsException.java

@@ -1,8 +1,11 @@
 package de.digitalcollections.model.exception.http.client;
 
+import org.zalando.problem.Problem;
+
 public class UnavailableForLegalReasonsException extends HttpClientException {
 
-  public UnavailableForLegalReasonsException(String methodKey, int status, String request) {
-    super(methodKey, status, request);
+  public UnavailableForLegalReasonsException(
+      String methodKey, int status, String request, Problem problem) {
+    super(methodKey, status, request, problem);
   }
 }

metasvc-model/src/main/java/de/digitalcollections/model/exception/http/client/UnprocessableEntityException.java

@@ -1,8 +1,11 @@
 package de.digitalcollections.model.exception.http.client;
 
+import org.zalando.problem.Problem;
+
 public class UnprocessableEntityException extends HttpClientException {
 
-  public UnprocessableEntityException(String methodKey, int status, String request) {
-    super(methodKey, status, request);
+  public UnprocessableEntityException(
+      String methodKey, int status, String request, Problem problem) {
+    super(methodKey, status, request, problem);
   }
 }

metasvc-model/src/main/java/de/digitalcollections/model/exception/http/server/BadGatewayException.java

@@ -1,8 +1,10 @@
 package de.digitalcollections.model.exception.http.server;
 
+import org.zalando.problem.Problem;
+
 public class BadGatewayException extends HttpServerException {
 
-  public BadGatewayException(String methodKey, int status, String request) {
-    super(methodKey, status, request);
+  public BadGatewayException(String methodKey, int status, String request, Problem problem) {
+    super(methodKey, status, request, problem);
   }
 }

metasvc-model/src/main/java/de/digitalcollections/model/exception/http/server/GatewayTimeOutException.java

@@ -1,8 +1,10 @@
 package de.digitalcollections.model.exception.http.server;
 
+import org.zalando.problem.Problem;
+
 public class GatewayTimeOutException extends HttpServerException {
 
-  public GatewayTimeOutException(String methodKey, int status, String request) {
-    super(methodKey, status, request);
+  public GatewayTimeOutException(String methodKey, int status, String request, Problem problem) {
+    super(methodKey, status, request, problem);
   }
 }