Added readInternal template method

Author: poutsma

org.springframework.web/src/main/java/org/springframework/http/converter/AbstractHttpMessageConverter.java

@@ -26,6 +26,7 @@
 import org.apache.commons.logging.LogFactory;
 
 import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpOutputMessage;
 import org.springframework.http.MediaType;
 import org.springframework.util.Assert;
@@ -34,8 +35,8 @@
  * Abstract base class for most {@link HttpMessageConverter} implementations.
  *
  * <p>This base class adds support for setting supported {@code MediaTypes}, through the {@link
- * #setSupportedMediaTypes(List) supportedMediaTypes} bean property. It also adds support for
- * {@code Content-Type} and {@code Content-Length} when writing to output messages.
+ * #setSupportedMediaTypes(List) supportedMediaTypes} bean property. It also adds support for {@code Content-Type} and
+ * {@code Content-Length} when writing to output messages.
  *
  * @author Arjen Poutsma
  * @since 3.0
@@ -76,11 +77,29 @@ public List<MediaType> getSupportedMediaTypes() {
 	}
 
 	/**
-	 * <p>This implementation delegates to {@link #getContentType(Object)} and {@link #getContentLength(Object)},
-	 * and sets the corresponding headers on the output message. It then calls
-	 * {@link #writeInternal(Object, HttpOutputMessage)}.
+	 * {@inheritDoc} <p>This implementation simple delegates to {@link #readInternal(Class, HttpInputMessage)}. Future
+	 * implementations might add some default behavior, however.
+	 */
+	public final T read(Class<T> clazz, HttpInputMessage inputMessage) throws IOException {
+		return readInternal(clazz, inputMessage);
+	}
+
+	/**
+	 * Abstract template method that reads the actualy object. Invoked from {@link #read(Class, HttpInputMessage)}.
 	 *
-	 * @throws HttpMessageConversionException in case of conversion errors
+	 * @param clazz the type of object to return
+	 * @param inputMessage the HTTP input message to read from
+	 * @return the converted object
+	 * @throws IOException in case of I/O errors
+	 * @throws HttpMessageNotReadableException in case of conversion errors
+	 */
+	protected abstract T readInternal(Class<T> clazz, HttpInputMessage inputMessage)
+			throws IOException, HttpMessageNotReadableException;
+
+	/**
+	 * {@inheritDoc} <p>This implementation delegates to {@link #getContentType(Object)} and {@link
+	 * #getContentLength(Object)}, and sets the corresponding headers on the output message. It then calls {@link
+	 * #writeInternal(Object, HttpOutputMessage)}.
 	 */
 	public final void write(T t, HttpOutputMessage outputMessage) throws IOException {
 		HttpHeaders headers = outputMessage.getHeaders();
@@ -97,9 +116,8 @@ public final void write(T t, HttpOutputMessage outputMessage) throws IOException
 	}
 
 	/**
-	 * Returns the content type for the given type.
-	 * <p>By default, this returns the first element of the {@link #setSupportedMediaTypes(List) supportedMediaTypes}
-	 * property, if any. Can be overriden in subclasses.
+	 * Returns the content type for the given type. <p>By default, this returns the first element of the {@link
+	 * #setSupportedMediaTypes(List) supportedMediaTypes} property, if any. Can be overriden in subclasses.
 	 *
 	 * @param t the type to return the content type for
 	 * @return the content type, or <code>null</code> if not known
@@ -110,8 +128,8 @@ protected MediaType getContentType(T t) {
 	}
 
 	/**
-	 * Returns the content length for the given type.
-	 * <p>By default, this returns <code>null</code>. Can be overriden in subclasses.
+	 * Returns the content length for the given type. <p>By default, this returns <code>null</code>. Can be overriden in
+	 * subclasses.
 	 *
 	 * @param t the type to return the content length for
 	 * @return the content length, or <code>null</code> if not known
@@ -126,8 +144,9 @@ protected Long getContentLength(T t) {
 	 * @param t the object to write to the output message
 	 * @param outputMessage the message to write to
 	 * @throws IOException in case of I/O errors
-	 * @throws HttpMessageConversionException in case of conversion errors
+	 * @throws HttpMessageNotWritableException in case of conversion errors
 	 */
-	protected abstract void writeInternal(T t, HttpOutputMessage outputMessage) throws IOException;
+	protected abstract void writeInternal(T t, HttpOutputMessage outputMessage)
+			throws IOException, HttpMessageNotWritableException;
 
 }

org.springframework.web/src/main/java/org/springframework/http/converter/ByteArrayHttpMessageConverter.java

@@ -46,7 +46,8 @@ public boolean supports(Class<? extends byte[]> clazz) {
 		return byte[].class.equals(clazz);
 	}
 
-	public byte[] read(Class<byte[]> clazz, HttpInputMessage inputMessage) throws IOException {
+	@Override
+	public byte[] readInternal(Class<byte[]> clazz, HttpInputMessage inputMessage) throws IOException {
 		long contentLength = inputMessage.getHeaders().getContentLength();
 		if (contentLength >= 0) {
 			ByteArrayOutputStream bos = new ByteArrayOutputStream((int) contentLength);

org.springframework.web/src/main/java/org/springframework/http/converter/FormHttpMessageConverter.java

@@ -37,9 +37,9 @@
 /**
  * Implementation of {@link HttpMessageConverter} that can read and write form data.
  *
- * <p>By default, this converter reads and writes the media type ({@code application/x-www-form-urlencoded}). This
- * can be overridden by setting the {@link #setSupportedMediaTypes(java.util.List) supportedMediaTypes} property. Form
- * data is read from and written into a {@link MultiValueMap MultiValueMap&lt;String, String&gt;}.
+ * <p>By default, this converter reads and writes the media type ({@code application/x-www-form-urlencoded}). This can
+ * be overridden by setting the {@link #setSupportedMediaTypes(java.util.List) supportedMediaTypes} property. Form data
+ * is read from and written into a {@link MultiValueMap MultiValueMap&lt;String, String&gt;}.
  *
  * @author Arjen Poutsma
  * @see MultiValueMap
@@ -58,8 +58,9 @@ public boolean supports(Class<? extends MultiValueMap<String, String>> clazz) {
 		return MultiValueMap.class.isAssignableFrom(clazz);
 	}
 
-	public MultiValueMap<String, String> read(Class<MultiValueMap<String, String>> clazz, HttpInputMessage inputMessage)
-			throws IOException {
+	@Override
+	public MultiValueMap<String, String> readInternal(Class<MultiValueMap<String, String>> clazz,
+			HttpInputMessage inputMessage) throws IOException {
 		MediaType contentType = inputMessage.getHeaders().getContentType();
 		Charset charset = contentType.getCharSet() != null ? contentType.getCharSet() : DEFAULT_CHARSET;
 		String body = FileCopyUtils.copyToString(new InputStreamReader(inputMessage.getBody(), charset));

org.springframework.web/src/main/java/org/springframework/http/converter/HttpMessageConverter.java

@@ -33,33 +33,34 @@ public interface HttpMessageConverter<T> {
 
 	/**
 	 * Indicate whether the given class is supported by this converter.
+	 *
 	 * @param clazz the class to test for support
 	 * @return <code>true</code> if supported; <code>false</code> otherwise
 	 */
 	boolean supports(Class<? extends T> clazz);
 
-	/**
-	 * Return the list of {@link MediaType} objects supported by this converter.
-	 */
+	/** Return the list of {@link MediaType} objects supported by this converter. */
 	List<MediaType> getSupportedMediaTypes();
 
 	/**
 	 * Read an object of the given type form the given input message, and returns it.
+	 *
 	 * @param clazz the type of object to return
 	 * @param inputMessage the HTTP input message to read from
 	 * @return the converted object
 	 * @throws IOException in case of I/O errors
-	 * @throws HttpMessageConversionException in case of conversion errors
+	 * @throws HttpMessageNotReadableException in case of conversion errors
 	 */
-	T read(Class<T> clazz, HttpInputMessage inputMessage) throws IOException;
+	T read(Class<T> clazz, HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException;
 
 	/**
 	 * Write an given object to the given output message.
-	 * @param t	the object to write to the output message
+	 *
+	 * @param t the object to write to the output message
 	 * @param outputMessage the message to write to
 	 * @throws IOException in case of I/O errors
-	 * @throws HttpMessageConversionException in case of conversion errors
+	 * @throws HttpMessageNotWritableException in case of conversion errors
 	 */
-	void write(T t, HttpOutputMessage outputMessage) throws IOException;
+	void write(T t, HttpOutputMessage outputMessage) throws IOException, HttpMessageNotWritableException;
 
 }

org.springframework.web/src/main/java/org/springframework/http/converter/StringHttpMessageConverter.java

@@ -54,7 +54,8 @@ public boolean supports(Class<? extends String> clazz) {
 		return String.class.equals(clazz);
 	}
 
-	public String read(Class<String> clazz, HttpInputMessage inputMessage) throws IOException {
+	@Override
+	public String readInternal(Class<String> clazz, HttpInputMessage inputMessage) throws IOException {
 		MediaType contentType = inputMessage.getHeaders().getContentType();
 		Charset charset = contentType.getCharSet() != null ? contentType.getCharSet() : DEFAULT_CHARSET;
 		return FileCopyUtils.copyToString(new InputStreamReader(inputMessage.getBody(), charset));
@@ -86,8 +87,8 @@ protected void writeInternal(String s, HttpOutputMessage outputMessage) throws I
 	}
 
 	/**
-	 * Return the list of supported {@link Charset}.
-	 * <p>By default, returns {@link Charset#availableCharsets()}. Can be overridden in subclasses.
+	 * Return the list of supported {@link Charset}. <p>By default, returns {@link Charset#availableCharsets()}. Can be
+	 * overridden in subclasses.
 	 *
 	 * @return the list of accepted charsets
 	 */

org.springframework.web/src/main/java/org/springframework/http/converter/xml/AbstractXmlHttpMessageConverter.java

@@ -55,7 +55,8 @@ protected AbstractXmlHttpMessageConverter() {
 	}
 
 	/** Invokes {@link #readFromSource(Class, HttpHeaders, Source)}. */
-	public final T read(Class<T> clazz, HttpInputMessage inputMessage) throws IOException {
+	@Override
+	public final T readInternal(Class<T> clazz, HttpInputMessage inputMessage) throws IOException {
 		return readFromSource(clazz, inputMessage.getHeaders(), new StreamSource(inputMessage.getBody()));
 	}