Add support for deserializing LinkedHashSet

oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/jackson2/OAuth2AuthorizationServerJackson2Module.java

@@ -18,6 +18,7 @@
 import java.time.Duration;
 import java.util.Collections;
 import java.util.HashSet;
+import java.util.LinkedHashSet;
 
 import com.fasterxml.jackson.core.Version;
 import com.fasterxml.jackson.databind.module.SimpleModule;
@@ -71,6 +72,7 @@ public void setupModule(SetupContext context) {
 		context.setMixInAnnotations(Collections.unmodifiableMap(Collections.emptyMap()).getClass(),
 				UnmodifiableMapMixin.class);
 		context.setMixInAnnotations(HashSet.class, HashSetMixin.class);
+		context.setMixInAnnotations(LinkedHashSet.class, HashSetMixin.class);
 		context.setMixInAnnotations(OAuth2AuthorizationRequest.class, OAuth2AuthorizationRequestMixin.class);
 		context.setMixInAnnotations(Duration.class, DurationMixin.class);
 		context.setMixInAnnotations(SignatureAlgorithm.class, SignatureAlgorithmMixin.class);

oauth2-authorization-server/src/test/java/org/springframework/security/oauth2/server/authorization/jackson2/OAuth2AuthorizationServerJackson2ModuleTests.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2020-2021 the original author or 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
+ *
+ *      https://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 org.springframework.security.oauth2.server.authorization.jackson2;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedHashSet;
+import java.util.Map;
+import java.util.Set;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link OAuth2AuthorizationServerJackson2Module}.
+ *
+ * @author Steve Riesenberg
+ */
+public class OAuth2AuthorizationServerJackson2ModuleTests {
+
+	private static final TypeReference<Map<String, Object>> STRING_OBJECT_MAP = new TypeReference<Map<String, Object>>() {
+	};
+	private static final TypeReference<Set<String>> STRING_SET = new TypeReference<Set<String>>() {
+	};
+
+	private ObjectMapper objectMapper;
+
+	@Before
+	public void setup() {
+		this.objectMapper = new ObjectMapper();
+		this.objectMapper.registerModule(new OAuth2AuthorizationServerJackson2Module());
+	}
+
+	@Test
+	public void readValueWhenUnmodifiableMapThenSuccess() throws Exception {
+		Map<String, Object> map = Collections.unmodifiableMap(new HashMap<>(Collections.singletonMap("key", "value")));
+		String json = this.objectMapper.writeValueAsString(map);
+		assertThat(this.objectMapper.readValue(json, STRING_OBJECT_MAP)).isEqualTo(map);
+	}
+
+	@Test
+	public void readValueWhenHashSetThenSuccess() throws Exception {
+		Set<String> set = new HashSet<>(Arrays.asList("one", "two"));
+		String json = this.objectMapper.writeValueAsString(set);
+		assertThat(this.objectMapper.readValue(json, STRING_SET)).isEqualTo(set);
+	}
+
+	// gh-457
+	@Test
+	public void readValueWhenLinkedHashSetThenSuccess() throws Exception {
+		Set<String> set = new LinkedHashSet<>(Arrays.asList("one", "two"));
+		String json = this.objectMapper.writeValueAsString(set);
+		assertThat(this.objectMapper.readValue(json, STRING_SET)).isEqualTo(set);
+	}
+}