SO- 4890: support includeNull and pretty query parameters

core/com.b2international.snowowl.core.rest/src/com/b2international/snowowl/core/rest/SnowOwlApiConfig.java

@@ -17,10 +17,12 @@
 
 import java.lang.reflect.AnnotatedElement;
 import java.lang.reflect.Method;
+import java.util.BitSet;
 import java.util.List;
 import java.util.Map;
 import java.util.TimeZone;
 import java.util.function.Predicate;
+import java.util.stream.Stream;
 
 import javax.servlet.http.HttpServletRequest;
 
@@ -77,6 +79,9 @@
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
 import com.google.common.base.Charsets;
 import com.google.common.base.Strings;
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
 import com.google.common.collect.ImmutableMap;
 import com.google.inject.Provider;
 
@@ -94,20 +99,34 @@
 @PropertySource("classpath:com/b2international/snowowl/core/rest/service_configuration.properties")
 public class SnowOwlApiConfig extends WebMvcConfigurationSupport {
 
+	private static final String INCLUDE_NULL = "includeNull";
+	private static final int INCLUDE_NULL_IDX = 0;
+	private static final String PRETTY = "pretty";
+	private static final int PRETTY_IDX = 1;
+
 	static {
 		SpringDocUtils.getConfig().addResponseWrapperToIgnore(Promise.class);
 	}
 
 	@Autowired
 	private org.springframework.context.ApplicationContext ctx;
 
+	private final LoadingCache<BitSet, ObjectMapper> objectMappers = CacheBuilder.newBuilder().build(new CacheLoader<BitSet, ObjectMapper>() {
+		@Override
+		public ObjectMapper load(BitSet configuration) throws Exception {
+			ObjectMapper mapper = createObjectMapper();
+			mapper.setSerializationInclusion(configuration.get(INCLUDE_NULL_IDX) ? Include.ALWAYS : Include.NON_NULL);
+			mapper.configure(SerializationFeature.INDENT_OUTPUT, configuration.get(PRETTY_IDX));
+			return mapper;
+		}
+	});
+
 	@Bean
 	public OpenAPI openAPI() {
 		return new OpenAPI();
 	}
 
-	@Bean
-	public ObjectMapper objectMapper() {
+	public static ObjectMapper createObjectMapper() {
 		final ObjectMapper objectMapper = new ObjectMapper();
 		objectMapper.registerModule(new JavaTimeModule());
 		objectMapper.setSerializationInclusion(Include.NON_NULL);
@@ -120,6 +139,42 @@ public ObjectMapper objectMapper() {
 		return objectMapper;
 	}
 
+	@Bean
+	@Scope(scopeName = WebApplicationContext.SCOPE_REQUEST, proxyMode = ScopedProxyMode.TARGET_CLASS)
+	public ObjectMapper objectMapper(@Autowired HttpServletRequest request) {
+		return objectMappers.getUnchecked(toConfig(
+			extractBooleanQueryParameterValue(request, INCLUDE_NULL),
+			extractBooleanQueryParameterValue(request, PRETTY)
+		));
+	}
+
+	private BitSet toConfig(boolean...serializationFeatureValuesInOrder) {
+		if (serializationFeatureValuesInOrder == null) {
+			return new BitSet(0);
+		} 
+		BitSet config = new BitSet(serializationFeatureValuesInOrder.length);
+		for (int i = 0; i < serializationFeatureValuesInOrder.length; i++) {
+			config.set(i, serializationFeatureValuesInOrder[i]);
+		}
+		return config;
+	}
+
+	private boolean extractBooleanQueryParameterValue(HttpServletRequest request, String queryParameterKey) {
+		String[] values = request.getParameterMap().containsKey(queryParameterKey) ? request.getParameterMap().getOrDefault(queryParameterKey, null) : null;
+		if (values == null) {
+			// query parameter not present, means disable feature
+			return false;
+		} else if (values.length == 0) {
+			// no values present, but the key is present, enable feature 
+			return true;
+		} else {
+			// XXX due to a bug in jetty-server v9.x, query parameters are duplicated in the low-level request object
+			// allowing multiple values for now with empty or valid (true in this case) values here
+			// see this bug report for details https://github.com/eclipse/jetty.project/issues/2074
+			return Stream.of(values).allMatch(value -> value.isBlank() || "true".equals(value));
+		}
+	}
+
 	@Override
 	protected void addReturnValueHandlers(List<HandlerMethodReturnValueHandler> returnValueHandlers) {
 		returnValueHandlers.add(new PromiseMethodReturnValueHandler());
@@ -204,10 +259,13 @@ public void configureMessageConverters(final List<HttpMessageConverter<?>> conve
 		converters.add(new ByteArrayHttpMessageConverter());
 		converters.add(new ResourceHttpMessageConverter());
 		converters.add(new CsvMessageConverter());
+		// XXX using null value here as Spring calls a proxied method anyway which returns an already configured instance, see mapping2JacksonHttpMessageConverter Bean method
+		converters.add(mapping2JacksonHttpMessageConverter(null));
+	}
 
-		final MappingJackson2HttpMessageConverter jacksonConverter = new MappingJackson2HttpMessageConverter();
-		jacksonConverter.setObjectMapper(objectMapper());
-		converters.add(jacksonConverter);
+	@Bean
+	public MappingJackson2HttpMessageConverter mapping2JacksonHttpMessageConverter(ObjectMapper mapper) {
+		return new MappingJackson2HttpMessageConverter(mapper);
 	}
 
 	@Override

fhir/com.b2international.snowowl.fhir.rest.tests/src/com/b2international/snowowl/fhir/tests/FhirTest.java

@@ -39,7 +39,7 @@ public class FhirTest {
 
 	protected static final String TEST_DATE_STRING = "2018-03-23T07:49:40.000+0000"; //$NON-NLS-N$
 
-	protected static final ObjectMapper objectMapper = new SnowOwlApiConfig().objectMapper();
+	protected static final ObjectMapper objectMapper = SnowOwlApiConfig.createObjectMapper();
 
 	@Rule
 	public ExpectedException exception = ExpectedException.none();