/*
* 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
*
* 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.integration.mqtt.support;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.integration.handler.MessageProcessor;
import org.springframework.integration.support.AbstractIntegrationMessageBuilder;
import org.springframework.integration.support.DefaultMessageBuilderFactory;
import org.springframework.integration.support.MessageBuilderFactory;
import org.springframework.integration.support.utils.IntegrationUtils;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHeaders;
import org.springframework.messaging.converter.MessageConversionException;
import org.springframework.util.Assert;
/**
* Default implementation for mapping to/from Messages.
*
* @author Gary Russell
* @author Artem Bilan
* @since 4.0
*
*/
public class DefaultPahoMessageConverter implements MqttMessageConverter, BeanFactoryAware {
private final String charset;
private final int defaultQos;
private final MessageProcessor<Integer> qosProcessor;
private final boolean defaultRetained;
private final MessageProcessor<Boolean> retainedProcessor;
private volatile boolean payloadAsBytes = false;
private volatile BeanFactory beanFactory;
private volatile MessageBuilderFactory messageBuilderFactory = new DefaultMessageBuilderFactory();
private volatile boolean messageBuilderFactorySet;
/**
* Construct a converter with default options (qos=0, retain=false, charset=UTF-8).
*/
public DefaultPahoMessageConverter() {
this (0, false);
}
/**
* Construct a converter to create outbound messages with the supplied default qos and
* retain settings and a UTF-8 charset for converting outbound String payloads to
* {@code byte[]} and inbound {@code byte[]} to String (unless
* {@link #setPayloadAsBytes(boolean) payloadAdBytes} is true).
* @param defaultQos the default qos.
* @param defaultRetained the default retained.
*/
public DefaultPahoMessageConverter(int defaultQos, boolean defaultRetained) {
this(defaultQos, defaultRetained, "UTF-8");
}
/**
* Construct a converter with default options (qos=0, retain=false) and
* the supplied charset.
* @param charset the charset used to convert outbound String paylaods to {@code byte[]} and inbound
* {@code byte[]} to String (unless {@link #setPayloadAsBytes(boolean) payloadAdBytes} is true).
* @since 4.1.2
*/
public DefaultPahoMessageConverter(String charset) {
this(0, false, charset);
}
/**
* Construct a converter to create outbound messages with the supplied default qos and
* retain settings and the supplied charset.
* @param defaultQos the default qos.
* @param defaultRetained the default retained.
* @param charset the charset used to convert outbound String paylaods to
* {@code byte[]} and inbound {@code byte[]} to String (unless
* {@link #setPayloadAsBytes(boolean) payloadAdBytes} is true).
*/
public DefaultPahoMessageConverter(int defaultQos, boolean defaultRetained, String charset) {
this(defaultQos, MqttMessageConverter.defaultQosProcessor(), defaultRetained,
MqttMessageConverter.defaultRetainedProcessor(), charset);
}
/**
* Construct a converter to create outbound messages with the supplied default qos and
* retained message processors and a UTF-8 charset for converting outbound String payloads to
* {@code byte[]} and inbound {@code byte[]} to String (unless
* {@link #setPayloadAsBytes(boolean) payloadAdBytes} is true).
* @param defaultQos the default qos.
* @param qosProcessor a message processor to determine the qos.
* @param defaultRetained the default retained.
* @param retainedProcessor a message processor to determine the retained flag.
* @since 5.0
*/
public DefaultPahoMessageConverter(int defaultQos, MessageProcessor<Integer> qosProcessor, boolean defaultRetained,
MessageProcessor<Boolean> retainedProcessor) {
this(defaultQos, qosProcessor, defaultRetained, retainedProcessor, "UTF-8");
}
/**
* Construct a converter to create outbound messages with the supplied default qos and
* retain settings and the supplied charset.
* @param defaultQos the default qos.
* @param qosProcessor a message processor to determine the qos.
* @param defaultRetained the default retained.
* @param retainedProcessor a message processor to determine the retained flag.
* @param charset the charset used to convert outbound String paylaods to
* {@code byte[]} and inbound {@code byte[]} to String (unless
* {@link #setPayloadAsBytes(boolean) payloadAdBytes} is true).
* @since 5.0
*/
public DefaultPahoMessageConverter(int defaultQos, MessageProcessor<Integer> qosProcessor, boolean defaultRetained,
MessageProcessor<Boolean> retainedProcessor, String charset) {
Assert.notNull(qosProcessor, "'qosProcessor' cannot be null");
Assert.notNull(retainedProcessor, "'retainedProcessor' cannot be null");
this.defaultQos = defaultQos;
this.qosProcessor = qosProcessor;
this.defaultRetained = defaultRetained;
this.retainedProcessor = retainedProcessor;
this.charset = charset;
}
@Override
public final void setBeanFactory(BeanFactory beanFactory) {
this.beanFactory = beanFactory;
}
protected BeanFactory getBeanFactory() {
return this.beanFactory;
}
protected MessageBuilderFactory getMessageBuilderFactory() {
if (!this.messageBuilderFactorySet) {
if (this.beanFactory != null) {
this.messageBuilderFactory = IntegrationUtils.getMessageBuilderFactory(this.beanFactory);
}
this.messageBuilderFactorySet = true;
}
return this.messageBuilderFactory;
}
/**
* True if the converter should not convert the message payload to a String.
*
* @param payloadAsBytes The payloadAsBytes to set.
*/
public void setPayloadAsBytes(boolean payloadAsBytes) {
this.payloadAsBytes = payloadAsBytes;
}
public boolean isPayloadAsBytes() {
return this.payloadAsBytes;
}
@Override
public Message<?> toMessage(Object mqttMessage, MessageHeaders headers) {
Assert.isInstanceOf(MqttMessage.class, mqttMessage,
() -> "This converter can only convert an 'MqttMessage'; received: "
+ mqttMessage.getClass().getName());
return toMessage(null, (MqttMessage) mqttMessage);
}
@Override
public Message<?> toMessage(String topic, MqttMessage mqttMessage) {
try {
AbstractIntegrationMessageBuilder<Object> messageBuilder = getMessageBuilderFactory()
.withPayload(mqttBytesToPayload(mqttMessage))
.setHeader(MqttHeaders.RECEIVED_QOS, mqttMessage.getQos())
.setHeader(MqttHeaders.DUPLICATE, mqttMessage.isDuplicate())
.setHeader(MqttHeaders.RECEIVED_RETAINED, mqttMessage.isRetained());
if (topic != null) {
messageBuilder.setHeader(MqttHeaders.RECEIVED_TOPIC, topic);
}
return messageBuilder.build();
}
catch (Exception e) {
throw new MessageConversionException("failed to convert object to Message", e);
}
}
@Override
public MqttMessage fromMessage(Message<?> message, Class<?> targetClass) {
byte[] payloadBytes = messageToMqttBytes(message);
MqttMessage mqttMessage = new MqttMessage(payloadBytes);
Integer qos = this.qosProcessor.processMessage(message);
mqttMessage.setQos(qos == null ? this.defaultQos : qos);
Boolean retained = this.retainedProcessor.processMessage(message);
mqttMessage.setRetained(retained == null ? this.defaultRetained : retained);
return mqttMessage;
}
/**
* Subclasses can override this method to convert the byte[] to a payload.
* The default implementation creates a String (default) or byte[].
*
* @param mqttMessage The inbound message.
* @return The payload for the Spring integration message
* @throws Exception Any.
*/
protected Object mqttBytesToPayload(MqttMessage mqttMessage) throws Exception {
if (this.payloadAsBytes) {
return mqttMessage.getPayload();
}
else {
return new String(mqttMessage.getPayload(), this.charset);
}
}
/**
* Subclasses can override this method to convert the payload to a byte[].
* The default implementation accepts a byte[] or String payload.
*
* @param message The outbound Message.
* @return The byte[] which will become the payload of the MQTT Message.
*/
protected byte[] messageToMqttBytes(Message<?> message) {
Object payload = message.getPayload();
Assert.isTrue(payload instanceof byte[] || payload instanceof String,
() -> "This default converter can only handle 'byte[]' or 'String' payloads; consider adding a "
+ "transformer to your flow definition, or subclass this converter for "
+ payload.getClass().getName() + " payloads");
byte[] payloadBytes;
if (payload instanceof String) {
try {
payloadBytes = ((String) payload).getBytes(this.charset);
}
catch (Exception e) {
throw new MessageConversionException("failed to convert Message to object", e);
}
}
else {
payloadBytes = (byte[]) payload;
}
return payloadBytes;
}
}