/*
* Copyright 2002-2009 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.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.ide.eclipse.wizard.gettingstarted.util;
import java.io.IOException;
import java.nio.charset.Charset;
import java.util.List;
import org.codehaus.jackson.JsonEncoding;
import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.type.TypeFactory;
import org.codehaus.jackson.type.JavaType;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.MediaType;
import org.springframework.http.converter.AbstractHttpMessageConverter;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.http.converter.HttpMessageNotWritableException;
import org.springframework.util.Assert;
//This is copy of MappingJacksonHttpMessageConverter from Spring 3. Slightly modified to compile
// in spring 4 and being compatible with old Jackson 1.6 library. The new version in spring 4
// requires more recent Jackons that do not ship with Eclipse.
/**
* Implementation of {@link org.springframework.http.converter.HttpMessageConverter HttpMessageConverter} that can read
* and write JSON using <a href="http://jackson.codehaus.org/">Jackson's</a> {@link ObjectMapper}.
*
* <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.
* method.
*
* @author Arjen Poutsma
* @see org.springframework.web.servlet.view.json.BindingJacksonJsonView
* @since 3.0
*/
public class Spring3MappingJacksonHttpMessageConverter extends AbstractHttpMessageConverter<Object> {
public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");
private ObjectMapper objectMapper = new ObjectMapper();
private boolean prefixJson = false;
/** Construct a new {@code BindingJacksonHttpMessageConverter}, */
public Spring3MappingJacksonHttpMessageConverter() {
super(
new MediaType("application", "json", DEFAULT_CHARSET),
new MediaType("text", "plain", DEFAULT_CHARSET) // download raw github url will give this even if file has json extension.
);
}
/**
* Sets the {@code ObjectMapper} for this view. If not set, a default {@link ObjectMapper#ObjectMapper() ObjectMapper}
* is used.
*
* <p>Setting a custom-configured {@code ObjectMapper} is one way to take further control of the JSON serialization
* process. For example, an extended {@link org.codehaus.jackson.map.SerializerFactory} can be configured that provides
* custom serializers for specific types. The other option for refining the serialization process is to use Jackson's
* provided annotations on the types to be serialized, in which case a custom-configured ObjectMapper is unnecessary.
*/
public void setObjectMapper(ObjectMapper objectMapper) {
Assert.notNull(objectMapper, "'objectMapper' must not be null");
this.objectMapper = objectMapper;
}
/**
* Indicates whether the JSON output by this view should be prefixed with "{} &&". Default is false.
*
* <p> Prefixing the JSON string in this manner is used to help prevent JSON Hijacking. The prefix renders the string
* syntactically invalid as a script so that it cannot be hijacked. This prefix does not affect the evaluation of JSON,
* but if JSON validation is performed on the string, the prefix would need to be ignored.
*/
public void setPrefixJson(boolean prefixJson) {
this.prefixJson = prefixJson;
}
@Override
public boolean canRead(Class<?> clazz, MediaType mediaType) {
JavaType javaType = TypeFactory.fromClass(clazz);
return objectMapper.canDeserialize(javaType) && isSupported(mediaType);
}
private boolean isSupported(MediaType mediaType) {
List<MediaType> supported = getSupportedMediaTypes();
for (MediaType s : supported) {
if (s.includes(mediaType)) {
return true;
}
}
return false;
}
@Override
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 Object readInternal(Class<?> clazz, HttpInputMessage inputMessage)
throws IOException, HttpMessageNotReadableException, HttpMessageNotReadableException {
return objectMapper.readValue(inputMessage.getBody(), clazz);
}
@Override
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, 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;
}
}