org.springframework.messaging.converter.StringMessageConverter Maven / Gradle / Ivy
/*
* Copyright 2002-2017 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
*
* 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 org.springframework.messaging.converter;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import org.springframework.lang.Nullable;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHeaders;
import org.springframework.util.Assert;
import org.springframework.util.MimeType;
/**
* A {@link MessageConverter} that supports MIME type "text/plain" with the
* payload converted to and from a String.
*
* @author Rossen Stoyanchev
* @since 4.0
*/
public class StringMessageConverter extends AbstractMessageConverter {
private final Charset defaultCharset;
public StringMessageConverter() {
this(StandardCharsets.UTF_8);
}
public StringMessageConverter(Charset defaultCharset) {
super(new MimeType("text", "plain", defaultCharset));
Assert.notNull(defaultCharset, "Default Charset must not be null");
this.defaultCharset = defaultCharset;
}
@Override
protected boolean supports(Class clazz) {
return (String.class == clazz);
}
@Override
protected Object convertFromInternal(Message message, Class targetClass, @Nullable Object conversionHint) {
Charset charset = getContentTypeCharset(getMimeType(message.getHeaders()));
Object payload = message.getPayload();
return (payload instanceof String ? payload : new String((byte[]) payload, charset));
}
@Override
@Nullable
protected Object convertToInternal(
Object payload, @Nullable MessageHeaders headers, @Nullable Object conversionHint) {
if (byte[].class == getSerializedPayloadClass()) {
Charset charset = getContentTypeCharset(getMimeType(headers));
payload = ((String) payload).getBytes(charset);
}
return payload;
}
private Charset getContentTypeCharset(@Nullable MimeType mimeType) {
if (mimeType != null && mimeType.getCharset() != null) {
return mimeType.getCharset();
}
else {
return this.defaultCharset;
}
}
}