com.c4_soft.springaddons.test.support.web.SerializationHelper Maven / Gradle / Ivy
/*
* Copyright 2018 Jérôme Wacongne.
*
* 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
*
* https://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 com.c4_soft.springaddons.test.support.web;
import java.io.IOException;
import org.springframework.beans.factory.ObjectFactory;
import org.springframework.boot.autoconfigure.http.HttpMessageConverters;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
/**
* Helps with HTTP requests body serialization using Spring registered message converters.
*
* @author Jérôme Wacongne <ch4mp@c4-soft.com>
*/
public class SerializationHelper {
private final ObjectFactory messageConverters;
public SerializationHelper(final ObjectFactory messageConverters) {
this.messageConverters = messageConverters;
}
/**
* Serializes objects (request payloads) to any media-type using registered HTTP message converters. Each acceptable converter
* ({@link org.springframework.http.converter.HttpMessageConverter#canWrite(Class, MediaType) converter.canWrite(payload.getClass(), mediaType)} return
* true) is tried until one actually succeeds at serializing.
*
* @param payload type
* @param payload request body to serialize
* @param mediaType expected body media-type
* @return serialized payload in JSON, XML, or whatever media-type an HttpMessageConverter is registered for
*/
public ByteArrayHttpOutputMessage outputMessage(final T payload, final MediaType mediaType) {
if (payload == null) {
return null;
}
@SuppressWarnings("unchecked")
final var relevantConverters = messageConverters.getObject().getConverters().stream()
.filter(converter -> converter.canWrite(payload.getClass(), mediaType)).map(c -> (HttpMessageConverter) c)// safe to cast as "canWrite"...
.toList();
final var converted = new ByteArrayHttpOutputMessage();
var isConverted = false;
for (final HttpMessageConverter converter : relevantConverters) {
try {
converted.headers.setContentType(mediaType);
converter.write(payload, mediaType, converted);
isConverted = true; // won't be reached if a conversion error occurs
break; // stop iterating over converters after first successful conversion
} catch (final IOException e) {
// swallow exception so that next converter is tried
}
}
if (!isConverted) {
throw new ConversionFailedException("Could not convert " + payload.getClass() + " to " + mediaType.toString());
}
return converted;
}
/**
* Provides with a String representation of provided payload using {@code outputMessage(Object, MediaType)}
*
* @param payload type
* @param payload request body to serialize
* @param mediaType expected body media-type
* @return serialized payload in JSON, XML, or whatever media-type an HttpMessageConverter is registered for
*/
public String asString(final T payload, final MediaType mediaType) {
return payload == null ? null : outputMessage(payload, mediaType).out.toString();
}
public String asJsonString(final T payload) {
return asString(payload, MediaType.APPLICATION_JSON);
}
public String asXmlnString(final T payload) {
return asString(payload, MediaType.APPLICATION_XML);
}
}