Restore Compatibility with OSIAM <= 2.x

The new SCIM error message construct is not backwards compatible with
OSIAM <= 2.x. This commit restores the compatibility by trying to first
read the new construct and then the old one, if the first read fails. Any
further processing is the same as before.

Author: tkrille

src/main/java/org/osiam/client/AbstractOsiamService.java

@@ -23,11 +23,33 @@
 
 package org.osiam.client;
 
-import static com.google.common.base.Preconditions.*;
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
 
-import java.io.IOException;
-import java.lang.reflect.ParameterizedType;
-import java.util.List;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.Version;
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.JavaType;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.fasterxml.jackson.databind.type.TypeFactory;
+import com.google.common.base.Strings;
+import org.osiam.client.exception.ConflictException;
+import org.osiam.client.exception.ConnectionInitializationException;
+import org.osiam.client.exception.ForbiddenException;
+import org.osiam.client.exception.NoResultException;
+import org.osiam.client.exception.OAuthErrorMessage;
+import org.osiam.client.exception.OsiamClientException;
+import org.osiam.client.exception.OsiamRequestException;
+import org.osiam.client.exception.ScimErrorMessage;
+import org.osiam.client.exception.UnauthorizedException;
+import org.osiam.client.oauth.AccessToken;
+import org.osiam.client.query.Query;
+import org.osiam.client.query.QueryBuilder;
+import org.osiam.resources.helper.UserDeserializer;
+import org.osiam.resources.scim.Resource;
+import org.osiam.resources.scim.SCIMSearchResult;
+import org.osiam.resources.scim.User;
 
 import javax.ws.rs.ProcessingException;
 import javax.ws.rs.client.Entity;
@@ -37,23 +59,10 @@
 import javax.ws.rs.core.Response.Status;
 import javax.ws.rs.core.Response.Status.Family;
 import javax.ws.rs.core.Response.StatusType;
-
-import org.osiam.client.exception.*;
-import org.osiam.client.oauth.AccessToken;
-import org.osiam.client.query.Query;
-import org.osiam.client.query.QueryBuilder;
-import org.osiam.resources.helper.UserDeserializer;
-import org.osiam.resources.scim.Resource;
-import org.osiam.resources.scim.SCIMSearchResult;
-import org.osiam.resources.scim.User;
-
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.core.Version;
-import com.fasterxml.jackson.databind.JavaType;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.module.SimpleModule;
-import com.fasterxml.jackson.databind.type.TypeFactory;
-import com.google.common.base.Strings;
+import java.io.IOException;
+import java.lang.reflect.ParameterizedType;
+import java.util.List;
+import java.util.Map;
 
 /**
  * AbstractOsiamService provides all basic methods necessary to manipulate the Entities registered in the given OSIAM
@@ -289,7 +298,10 @@ protected String extractErrorMessageDefault(String content, StatusType status) {
 
     protected String extractErrorMessage(String content, StatusType status) {
 
-        String message = getScimErrorMessage(content);
+        String message = getScimErrorMessageSinceOsiam3(content);
+        if (message == null) {
+            message = getScimErrorMessageUpToOsiam2(content);
+        }
         if (message == null) {
             message = getOAuthErrorMessage(content);
         }
@@ -303,18 +315,27 @@ protected String extractErrorMessage(String content, StatusType status) {
         return message;
     }
 
-    private String getScimErrorMessage(String content) {
+    private String getScimErrorMessageSinceOsiam3(String content) {
         try {
-            ScimErrorMessage error = new ObjectMapper().readValue(content, ScimErrorMessage.class);
+            ScimErrorMessage error = mapper.readValue(content, ScimErrorMessage.class);
             return error.getDetail();
         } catch (ProcessingException | IOException e) {
             return null;
         }
     }
 
+    private String getScimErrorMessageUpToOsiam2(String content) {
+        try {
+            Map<String, String> error = mapper.readValue(content, new TypeReference<Map<String, String>>() {});
+            return error.get("description");
+        } catch (ProcessingException | IOException e) {
+            return null;
+        }
+    }
+
     private String getOAuthErrorMessage(String content) {
         try {
-            OAuthErrorMessage error = new ObjectMapper().readValue(content, OAuthErrorMessage.class);
+            OAuthErrorMessage error = mapper.readValue(content, OAuthErrorMessage.class);
             return error.getDescription();
         } catch (ProcessingException | IOException e) {
             return null;
@@ -326,6 +347,7 @@ protected static void checkAccessTokenIsNotNull(AccessToken accessToken) {
     }
 
     protected static class Builder<T> {
+
         private String endpoint;
         private Class<T> type;
         private String typeName;