Make JsonObjectDecoder mandatory in JacksonJsonDecoder

spring-web-reactive/src/main/java/org/springframework/core/codec/support/JacksonJsonDecoder.java

@@ -45,22 +45,17 @@ public class JacksonJsonDecoder extends AbstractDecoder<Object> {
 
 	private final ObjectMapper mapper;
 
-	private Decoder<DataBuffer> preProcessor;
+	private final Decoder<DataBuffer> preProcessor = new JsonObjectDecoder();
 
 
 	public JacksonJsonDecoder() {
-		this(new ObjectMapper(), null);
+		this(new ObjectMapper());
 	}
 
-	public JacksonJsonDecoder(Decoder<DataBuffer> preProcessor) {
-		this(new ObjectMapper(), preProcessor);
-	}
-
-	public JacksonJsonDecoder(ObjectMapper mapper, Decoder<DataBuffer> preProcessor) {
+	public JacksonJsonDecoder(ObjectMapper mapper) {
 		super(new MimeType("application", "json", StandardCharsets.UTF_8),
 				new MimeType("application", "*+json", StandardCharsets.UTF_8));
 		this.mapper = mapper;
-		this.preProcessor = preProcessor;
 	}
 
 	@Override

spring-web-reactive/src/main/java/org/springframework/web/client/reactive/WebClient.java

@@ -28,7 +28,6 @@ import org.springframework.core.codec.support.ByteBufferDecoder;
 import org.springframework.core.codec.support.ByteBufferEncoder;
 import org.springframework.core.codec.support.JacksonJsonDecoder;
 import org.springframework.core.codec.support.JacksonJsonEncoder;
-import org.springframework.core.codec.support.JsonObjectDecoder;
 import org.springframework.core.codec.support.StringDecoder;
 import org.springframework.core.codec.support.StringEncoder;
 import org.springframework.http.HttpStatus;
@@ -86,7 +85,7 @@ public final class WebClient {
 		this.messageEncoders = Arrays.asList(new ByteBufferEncoder(), new StringEncoder(),
 				new JacksonJsonEncoder());
 		this.messageDecoders = Arrays.asList(new ByteBufferDecoder(), new StringDecoder(),
-				new JacksonJsonDecoder(new JsonObjectDecoder()));
+				new JacksonJsonDecoder());
 	}
 
 	/**

spring-web-reactive/src/main/java/org/springframework/web/reactive/config/WebReactiveConfiguration.java

@@ -36,7 +36,6 @@ import org.springframework.core.codec.support.JacksonJsonDecoder;
 import org.springframework.core.codec.support.JacksonJsonEncoder;
 import org.springframework.core.codec.support.Jaxb2Decoder;
 import org.springframework.core.codec.support.Jaxb2Encoder;
-import org.springframework.core.codec.support.JsonObjectDecoder;
 import org.springframework.core.codec.support.StringDecoder;
 import org.springframework.core.codec.support.StringEncoder;
 import org.springframework.core.convert.converter.Converter;
@@ -251,7 +250,7 @@ public class WebReactiveConfiguration implements ApplicationContextAware {
 		}
 		if (jackson2Present) {
 			JacksonJsonEncoder jacksonEncoder = new JacksonJsonEncoder();
-			JacksonJsonDecoder jacksonDecoder = new JacksonJsonDecoder(new JsonObjectDecoder());
+			JacksonJsonDecoder jacksonDecoder = new JacksonJsonDecoder();
 			converters.add(converter(jacksonEncoder, jacksonDecoder));
 			sseDataEncoders.add(jacksonEncoder);
 		} else {

spring-web-reactive/src/test/java/org/springframework/core/codec/support/JacksonJsonDecoderTests.java

@@ -59,8 +59,8 @@ public class JacksonJsonDecoderTests extends AbstractDataBufferAllocatingTestCas
 	}
 
 	@Test
-	@Ignore // Issues 112 (no generic type), otherwise works
-	public void decodeToListWithoutObjectDecoder() throws Exception {
+	@Ignore // Issue 109
+	public void decodeToList() throws Exception {
 		Flux<DataBuffer> source = Flux.just(stringBuffer(
 				"[{\"bar\":\"b1\",\"foo\":\"f1\"},{\"bar\":\"b2\",\"foo\":\"f2\"}]"));
 
@@ -73,8 +73,7 @@ public class JacksonJsonDecoderTests extends AbstractDataBufferAllocatingTestCas
 	}
 
 	@Test
-	@Ignore // Issue 109
-	public void decodeToFluxWithoutObjectDecoder() throws Exception {
+	public void decodeToFlux() throws Exception {
 		Flux<DataBuffer> source = Flux.just(stringBuffer(
 				"[{\"bar\":\"b1\",\"foo\":\"f1\"},{\"bar\":\"b2\",\"foo\":\"f2\"}]"));
 
@@ -85,32 +84,6 @@ public class JacksonJsonDecoderTests extends AbstractDataBufferAllocatingTestCas
 				assertValues(new Pojo("f1", "b1"), new Pojo("f2", "b2"));
 	}
 
-	@Test
-	@Ignore // Issue 109
-	public void decodeToListWithObjectDecoder() throws Exception {
-		Flux<DataBuffer> source = Flux.just(stringBuffer(
-				"[{\"bar\":\"b1\",\"foo\":\"f1\"},{\"bar\":\"b2\",\"foo\":\"f2\"}]"));
-
-		Method method = getClass().getDeclaredMethod("handle", List.class);
-		ResolvableType elementType = ResolvableType.forMethodParameter(method, 0);
-		Flux<Object> flux = new JacksonJsonDecoder(new JsonObjectDecoder()).decode(source, elementType, null);
-
-		TestSubscriber.subscribe(flux).assertNoError().assertComplete().
-				assertValues(Arrays.asList(new Pojo("f1", "b1"), new Pojo("f2", "b2")));
-	}
-
-	@Test
-	public void decodeToFluxWithObjectDecoder() throws Exception {
-		Flux<DataBuffer> source = Flux.just(stringBuffer(
-				"[{\"bar\":\"b1\",\"foo\":\"f1\"},{\"bar\":\"b2\",\"foo\":\"f2\"}]"));
-
-		ResolvableType elementType = ResolvableType.forClass(Pojo.class);
-		Flux<Object> flux = new JacksonJsonDecoder(new JsonObjectDecoder()).decode(source, elementType, null);
-
-		TestSubscriber.subscribe(flux).assertNoError().assertComplete().
-				assertValues(new Pojo("f1", "b1"), new Pojo("f2", "b2"));
-	}
-
 	@SuppressWarnings("unused")
 	void handle(List<Pojo> list) {
 	}

spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/RequestBodyArgumentResolverTests.java

@@ -44,7 +44,6 @@ import org.springframework.core.ParameterNameDiscoverer;
 import org.springframework.core.annotation.SynthesizingMethodParameter;
 import org.springframework.core.codec.Decoder;
 import org.springframework.core.codec.support.JacksonJsonDecoder;
-import org.springframework.core.codec.support.JsonObjectDecoder;
 import org.springframework.core.codec.support.StringDecoder;
 import org.springframework.core.convert.support.GenericConversionService;
 import org.springframework.core.convert.support.ReactiveStreamsToCompletableFutureConverter;
@@ -93,7 +92,7 @@ public class RequestBodyArgumentResolverTests {
 
 	@Before
 	public void setUp() throws Exception {
-		this.resolver = resolver(new JacksonJsonDecoder(new JsonObjectDecoder()));
+		this.resolver = resolver(new JacksonJsonDecoder());
 		this.request = new MockServerHttpRequest(HttpMethod.GET, new URI("/path"));
 		MockServerHttpResponse response = new MockServerHttpResponse();
 		DefaultWebSessionManager sessionManager = new DefaultWebSessionManager();

spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/SseIntegrationTests.java

@@ -33,7 +33,6 @@ import org.springframework.core.codec.Encoder;
 import org.springframework.core.codec.support.ByteBufferDecoder;
 import org.springframework.core.codec.support.JacksonJsonDecoder;
 import org.springframework.core.codec.support.JacksonJsonEncoder;
-import org.springframework.core.codec.support.JsonObjectDecoder;
 import org.springframework.core.codec.support.StringDecoder;
 import org.springframework.http.MediaType;
 import org.springframework.http.client.reactive.ReactorHttpClientRequestFactory;
@@ -69,7 +68,7 @@ public class SseIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 		this.webClient.setMessageDecoders(Arrays.asList(
 				new ByteBufferDecoder(),
 				new StringDecoder(false),
-				new JacksonJsonDecoder(new JsonObjectDecoder())));
+				new JacksonJsonDecoder()));
 	}
 
 	@Override