SPR-6386 - MappingJacksonHttpMessageConverter ignores supported media types property

Author: poutsma

org.springframework.web/src/main/java/org/springframework/http/converter/json/MappingJacksonHttpMessageConverter.java

@@ -20,9 +20,14 @@
 import java.nio.charset.Charset;
 import java.util.List;
 
+import javax.xml.bind.Marshaller;
+import javax.xml.bind.PropertyException;
+
 import org.codehaus.jackson.JsonEncoding;
 import org.codehaus.jackson.JsonGenerator;
+import org.codehaus.jackson.type.JavaType;
 import org.codehaus.jackson.map.ObjectMapper;
+import org.codehaus.jackson.map.type.TypeFactory;
 
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpOutputMessage;
@@ -39,24 +44,24 @@
  * <p>This converter can be used to bind to typed beans, or untyped {@link java.util.HashMap HashMap} instances.
  *
  * <p>By default, this converter supports {@code application/json}. This can be overridden by setting the {@link
- * #setSupportedMediaTypes(List) supportedMediaTypes} property, and overriding the {@link #getContentType(Object)}
+ * #setSupportedMediaTypes(List) supportedMediaTypes} property.
  * method.
  *
  * @author Arjen Poutsma
  * @see org.springframework.web.servlet.view.json.BindingJacksonJsonView
  * @since 3.0
  */
-public class MappingJacksonHttpMessageConverter<T> extends AbstractHttpMessageConverter<T> {
+public class MappingJacksonHttpMessageConverter extends AbstractHttpMessageConverter<Object> {
 
-	private ObjectMapper objectMapper = new ObjectMapper();
+	public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");
 
-	private JsonEncoding encoding = JsonEncoding.UTF8;
+	private ObjectMapper objectMapper = new ObjectMapper();
 
 	private boolean prefixJson = false;
 
 	/** Construct a new {@code BindingJacksonHttpMessageConverter}, */
 	public MappingJacksonHttpMessageConverter() {
-		super(new MediaType("application", "json"));
+		super(new MediaType("application", "json", DEFAULT_CHARSET));
 	}
 
 	/**
@@ -73,12 +78,6 @@ public void setObjectMapper(ObjectMapper objectMapper) {
 		this.objectMapper = objectMapper;
 	}
 
-	/** Sets the {@code JsonEncoding} for this converter. By default, {@linkplain JsonEncoding#UTF8 UTF-8} is used. */
-	public void setEncoding(JsonEncoding encoding) {
-		Assert.notNull(encoding, "'encoding' must not be null");
-		this.encoding = encoding;
-	}
-
 	/**
 	 * Indicates whether the JSON output by this view should be prefixed with "{} &&". Default is false.
 	 *
@@ -91,30 +90,50 @@ public void setPrefixJson(boolean prefixJson) {
 	}
 
 	@Override
-	public boolean supports(Class<? extends T> clazz) {
-		return objectMapper.canSerialize(clazz);
+	public boolean canRead(Class<?> clazz, MediaType mediaType) {
+		JavaType javaType = TypeFactory.fromClass(clazz);
+		return objectMapper.canDeserialize(javaType) && isSupported(mediaType);
 	}
 
 	@Override
-	protected T readInternal(Class<T> clazz, HttpInputMessage inputMessage)
-			throws IOException, HttpMessageNotReadableException {
-		return objectMapper.readValue(inputMessage.getBody(), clazz);
+	public boolean canWrite(Class<?> clazz, MediaType mediaType) {
+		return objectMapper.canSerialize(clazz) && isSupported(mediaType);
+	}
+
+	@Override
+	protected boolean supports(Class<?> clazz) {
+		// should not be called, since we override canRead/Write
+		throw new UnsupportedOperationException();
 	}
 
 	@Override
-	protected MediaType getDefaultContentType(T t) {
-		Charset charset = Charset.forName(encoding.getJavaName());
-		return new MediaType("application", "json", charset);
+	protected Object readInternal(Class<Object> clazz, HttpInputMessage inputMessage)
+			throws IOException, HttpMessageNotReadableException {
+		return objectMapper.readValue(inputMessage.getBody(), clazz);
 	}
 
 	@Override
-	protected void writeInternal(T t, HttpOutputMessage outputMessage)
+	protected void writeInternal(Object o, HttpOutputMessage outputMessage)
 			throws IOException, HttpMessageNotWritableException {
+		JsonEncoding encoding = getEncoding(outputMessage.getHeaders().getContentType());
 		JsonGenerator jsonGenerator =
 				objectMapper.getJsonFactory().createJsonGenerator(outputMessage.getBody(), encoding);
 		if (prefixJson) {
 			jsonGenerator.writeRaw("{} && ");
 		}
-		objectMapper.writeValue(jsonGenerator, t);
+		objectMapper.writeValue(jsonGenerator, o);
 	}
+
+	private JsonEncoding getEncoding(MediaType contentType) {
+		if (contentType != null && contentType.getCharSet() != null) {
+			Charset charset = contentType.getCharSet();
+			for (JsonEncoding encoding : JsonEncoding.values()) {
+				if (charset.name().equals(encoding.getJavaName())) {
+					return encoding;
+				}
+			}
+		}
+		return JsonEncoding.UTF8;
+	}
+
 }

org.springframework.web/src/test/java/org/springframework/http/converter/json/MappingJacksonHttpMessageConverterTests.java

@@ -21,6 +21,7 @@
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 import static org.junit.Assert.*;
 import org.junit.Before;
@@ -33,25 +34,33 @@
 /** @author Arjen Poutsma */
 public class MappingJacksonHttpMessageConverterTests {
 
-	private MappingJacksonHttpMessageConverter<MyBean> converter;
+	private MappingJacksonHttpMessageConverter converter;
 
 	@Before
 	public void setUp() {
-		converter = new MappingJacksonHttpMessageConverter<MyBean>();
+		converter = new MappingJacksonHttpMessageConverter();
 	}
 
 	@Test
-	public void supports() {
-		assertTrue(converter.supports(MyBean.class));
+	public void canRead() {
+		assertTrue(converter.canRead(MyBean.class, new MediaType("application", "json")));
+		assertTrue(converter.canRead(Map.class, new MediaType("application", "json")));
 	}
 
 	@Test
+	public void canWrite() {
+		assertTrue(converter.canWrite(MyBean.class, new MediaType("application", "json")));
+		assertTrue(converter.canWrite(Map.class, new MediaType("application", "json")));
+	}
+
+	@Test
+	@SuppressWarnings("unchecked")
 	public void readTyped() throws IOException {
 		String body =
 				"{\"bytes\":\"AQI=\",\"array\":[\"Foo\",\"Bar\"],\"number\":42,\"string\":\"Foo\",\"bool\":true,\"fraction\":42.0}";
 		MockHttpInputMessage inputMessage = new MockHttpInputMessage(body.getBytes("UTF-8"));
 		inputMessage.getHeaders().setContentType(new MediaType("application", "json"));
-		MyBean result = converter.read(MyBean.class, inputMessage);
+		MyBean result = (MyBean) converter.read((Class) MyBean.class, inputMessage);
 		assertEquals("Foo", result.getString());
 		assertEquals(42, result.getNumber());
 		assertEquals(42F, result.getFraction(), 0F);
@@ -61,14 +70,13 @@ public void readTyped() throws IOException {
 	}
 
 	@Test
-	@SuppressWarnings({"unchecked"})
+	@SuppressWarnings("unchecked")
 	public void readUntyped() throws IOException {
-		MappingJacksonHttpMessageConverter<HashMap> converter = new MappingJacksonHttpMessageConverter<HashMap>();
 		String body =
 				"{\"bytes\":\"AQI=\",\"array\":[\"Foo\",\"Bar\"],\"number\":42,\"string\":\"Foo\",\"bool\":true,\"fraction\":42.0}";
 		MockHttpInputMessage inputMessage = new MockHttpInputMessage(body.getBytes("UTF-8"));
 		inputMessage.getHeaders().setContentType(new MediaType("application", "json"));
-		HashMap<String, Object> result = converter.read(HashMap.class, inputMessage);
+		HashMap<String, Object> result = (HashMap<String, Object>) converter.read((Class)HashMap.class, inputMessage);
 		assertEquals("Foo", result.get("string"));
 		assertEquals(42, result.get("number"));
 		assertEquals(42D, (Double) result.get("fraction"), 0D);
@@ -103,6 +111,18 @@ public void write() throws IOException {
 				outputMessage.getHeaders().getContentType());
 	}
 
+	@Test
+	public void writeUTF16() throws IOException {
+		Charset utf16 = Charset.forName("UTF-16BE");
+		MediaType contentType = new MediaType("application", "json", utf16);
+		MockHttpOutputMessage outputMessage = new MockHttpOutputMessage();
+		String body = "H\u00e9llo W\u00f6rld";
+		converter.write(body, contentType, outputMessage);
+		assertEquals("Invalid result", "\"" + body + "\"", outputMessage.getBodyAsString(utf16));
+		assertEquals("Invalid content-type", contentType, outputMessage.getHeaders().getContentType());
+	}
+
+
 	public static class MyBean {
 
 		private String string;