Jackson-based message converters consistently check media type first

Issue: SPR-14163

Author: jhoeller

spring-messaging/src/main/java/org/springframework/messaging/converter/MappingJackson2MessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -142,20 +142,20 @@ private void configurePrettyPrint() {
 
 	@Override
 	protected boolean canConvertFrom(Message<?> message, Class<?> targetClass) {
-		if (targetClass == null) {
+		if (targetClass == null || !supportsMimeType(message.getHeaders())) {
 			return false;
 		}
 		JavaType javaType = this.objectMapper.constructType(targetClass);
 		if (!jackson23Available || !logger.isWarnEnabled()) {
-			return (this.objectMapper.canDeserialize(javaType) && supportsMimeType(message.getHeaders()));
+			return this.objectMapper.canDeserialize(javaType);
 		}
 		AtomicReference<Throwable> causeRef = new AtomicReference<Throwable>();
-		if (this.objectMapper.canDeserialize(javaType, causeRef) && supportsMimeType(message.getHeaders())) {
+		if (this.objectMapper.canDeserialize(javaType, causeRef)) {
 			return true;
 		}
 		Throwable cause = causeRef.get();
 		if (cause != null) {
-			String msg = "Failed to evaluate deserialization for type " + javaType;
+			String msg = "Failed to evaluate Jackson deserialization for type " + javaType;
 			if (logger.isDebugEnabled()) {
 				logger.warn(msg, cause);
 			}
@@ -168,16 +168,19 @@ protected boolean canConvertFrom(Message<?> message, Class<?> targetClass) {
 
 	@Override
 	protected boolean canConvertTo(Object payload, MessageHeaders headers) {
+		if (payload == null || !supportsMimeType(headers)) {
+			return false;
+		}
 		if (!jackson23Available || !logger.isWarnEnabled()) {
-			return (this.objectMapper.canSerialize(payload.getClass()) && supportsMimeType(headers));
+			return this.objectMapper.canSerialize(payload.getClass());
 		}
 		AtomicReference<Throwable> causeRef = new AtomicReference<Throwable>();
-		if (this.objectMapper.canSerialize(payload.getClass(), causeRef) && supportsMimeType(headers)) {
+		if (this.objectMapper.canSerialize(payload.getClass(), causeRef)) {
 			return true;
 		}
 		Throwable cause = causeRef.get();
 		if (cause != null) {
-			String msg = "Failed to evaluate serialization for type [" + payload.getClass() + "]";
+			String msg = "Failed to evaluate Jackson serialization for type [" + payload.getClass() + "]";
 			if (logger.isDebugEnabled()) {
 				logger.warn(msg, cause);
 			}

spring-web/src/main/java/org/springframework/http/converter/json/AbstractJackson2HttpMessageConverter.java

@@ -142,10 +142,10 @@ public boolean canRead(Class<?> clazz, MediaType mediaType) {
 
 	@Override
 	public boolean canRead(Type type, Class<?> contextClass, MediaType mediaType) {
-		JavaType javaType = getJavaType(type, contextClass);
 		if (!canRead(mediaType)) {
 			return false;
 		}
+		JavaType javaType = getJavaType(type, contextClass);
 		if (!jackson23Available || !logger.isWarnEnabled()) {
 			return this.objectMapper.canDeserialize(javaType);
 		}
@@ -155,7 +155,7 @@ public boolean canRead(Type type, Class<?> contextClass, MediaType mediaType) {
 		}
 		Throwable cause = causeRef.get();
 		if (cause != null) {
-			String msg = "Failed to evaluate deserialization for type " + javaType;
+			String msg = "Failed to evaluate Jackson deserialization for type " + javaType;
 			if (logger.isDebugEnabled()) {
 				logger.warn(msg, cause);
 			}
@@ -180,7 +180,7 @@ public boolean canWrite(Class<?> clazz, MediaType mediaType) {
 		}
 		Throwable cause = causeRef.get();
 		if (cause != null) {
-			String msg = "Failed to evaluate serialization for type [" + clazz + "]";
+			String msg = "Failed to evaluate Jackson serialization for type [" + clazz + "]";
 			if (logger.isDebugEnabled()) {
 				logger.warn(msg, cause);
 			}

spring-web/src/test/java/org/springframework/http/converter/json/MappingJackson2HttpMessageConverterTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -31,7 +31,6 @@
 import com.fasterxml.jackson.databind.ser.FilterProvider;
 import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
 import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
-
 import org.junit.Test;
 
 import org.springframework.core.ParameterizedTypeReference;
@@ -68,9 +67,7 @@ public void canWrite() {
 		assertTrue(converter.canWrite(Map.class, new MediaType("application", "json")));
 	}
 
-	// SPR-7905
-
-	@Test
+	@Test  // SPR-7905
 	public void canReadAndWriteMicroformats() {
 		assertTrue(converter.canRead(MyBean.class, new MediaType("application", "vnd.test-micro-type+json")));
 		assertTrue(converter.canWrite(MyBean.class, new MediaType("application", "vnd.test-micro-type+json")));
@@ -439,9 +436,12 @@ public void setName(String name) {
 		}
 	}
 
+
 	private interface MyJacksonView1 {};
+
 	private interface MyJacksonView2 {};
 
+
 	@SuppressWarnings("unused")
 	private static class JacksonViewBean {
 
@@ -478,11 +478,13 @@ public void setWithoutView(String withoutView) {
 		}
 	}
 
+
 	@JsonFilter("myJacksonFilter")
 	@SuppressWarnings("unused")
 	private static class JacksonFilteredBean {
 
 		private String property1;
+
 		private String property2;
 
 		public String getProperty1() {