org.springframework.messaging.support.AbstractHeaderMapper Maven / Gradle / Ivy
/*
* Copyright 2002-2018 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.support;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.lang.Nullable;
import org.springframework.messaging.MessageHeaders;
import org.springframework.util.StringUtils;
/**
* A base {@link HeaderMapper} implementation.
*
* @author Stephane Nicoll
* @since 4.1
* @param type of the instance to and from which headers will be mapped
*/
public abstract class AbstractHeaderMapper implements HeaderMapper {
protected final Log logger = LogFactory.getLog(getClass());
private String inboundPrefix = "";
private String outboundPrefix = "";
/**
* Specify a prefix to be appended to the message header name for any
* user-defined property that is being mapped into the MessageHeaders.
* The default is an empty String (no prefix).
*/
public void setInboundPrefix(@Nullable String inboundPrefix) {
this.inboundPrefix = (inboundPrefix != null ? inboundPrefix : "");
}
/**
* Specify a prefix to be appended to the protocol property name for any
* user-defined message header that is being mapped into the protocol-specific
* Message. The default is an empty String (no prefix).
*/
public void setOutboundPrefix(@Nullable String outboundPrefix) {
this.outboundPrefix = (outboundPrefix != null ? outboundPrefix : "");
}
/**
* Generate the name to use to set the header defined by the specified
* {@code headerName} to the protocol specific message.
* @see #setOutboundPrefix
*/
protected String fromHeaderName(String headerName) {
String propertyName = headerName;
if (StringUtils.hasText(this.outboundPrefix) && !propertyName.startsWith(this.outboundPrefix)) {
propertyName = this.outboundPrefix + headerName;
}
return propertyName;
}
/**
* Generate the name to use to set the header defined by the specified
* {@code propertyName} to the {@link MessageHeaders} instance.
* @see #setInboundPrefix(String)
*/
protected String toHeaderName(String propertyName) {
String headerName = propertyName;
if (StringUtils.hasText(this.inboundPrefix) && !headerName.startsWith(this.inboundPrefix)) {
headerName = this.inboundPrefix + propertyName;
}
return headerName;
}
/**
* Return the header value, or {@code null} if it does not exist
* or does not match the requested {@code type}.
*/
@Nullable
protected V getHeaderIfAvailable(Map headers, String name, Class type) {
Object value = headers.get(name);
if (value == null) {
return null;
}
if (!type.isAssignableFrom(value.getClass())) {
if (logger.isDebugEnabled()) {
logger.debug("Skipping header '" + name + "': expected type [" + type + "], but got [" +
value.getClass() + "]");
}
return null;
}
else {
return type.cast(value);
}
}
}