Chapter 109. Paho Both producer and consumer are supported Paho component provides connector for the MQTT messaging protocol using the Eclipse Paho library . Paho is one of the most popular MQTT libraries, so if you would like to integrate it with your Java project - Camel Paho connector is a way to go. 109.1. Dependencies When using paho with Red Hat build of Camel Spring Boot make sure to use the following Maven dependency to have support for auto configuration: <dependency> <groupId>org.apache.camel.springboot</groupId> <artifactId>camel-paho-starter</artifactId> </dependency> 109.2. URI format paho:topic[?options] Where topic is the name of the topic. 109.3. Configuring Options Camel components are configured on two separate levels: component level endpoint level 109.3.1. Configuring Component Options At the component level, you set general and shared configurations that are, then, inherited by the endpoints. It is the highest configuration level. For example, a component may have security settings, credentials for authentication, urls for network connection and so forth. Some components only have a few options, and others may have many. Because components typically have pre-configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all. You can configure components using: the Component DSL . in a configuration file (application.properties, *.yaml files, etc). directly in the Java code. 109.3.2. Configuring Endpoint Options You usually spend more time setting up endpoints because they have many options. These options help you customize what you want the endpoint to do. The options are also categorized into whether the endpoint is used as a consumer (from), as a producer (to), or both. Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java. A good practice when configuring options is to use Property Placeholders . Property placeholders provide a few benefits: They help prevent using hardcoded urls, port numbers, sensitive information, and other settings. They allow externalizing the configuration from the code. They help the code to become more flexible and reusable. The following two sections list all the options, firstly for the component followed by the endpoint. 109.4. Component Options The Paho component supports 31 options, which are listed below. Name Description Default Type automaticReconnect (common) Sets whether the client will automatically attempt to reconnect to the server if the connection is lost. If set to false, the client will not attempt to automatically reconnect to the server in the event that the connection is lost. If set to true, in the event that the connection is lost, the client will attempt to reconnect to the server. It will initially wait 1 second before it attempts to reconnect, for every failed reconnect attempt, the delay will double until it is at 2 minutes at which point the delay will stay at 2 minutes. true boolean brokerUrl (common) The URL of the MQTT broker. tcp://localhost:1883 String cleanSession (common) Sets whether the client and server should remember state across restarts and reconnects. If set to false both the client and server will maintain state across restarts of the client, the server and the connection. As state is maintained: Message delivery will be reliable meeting the specified QOS even if the client, server or connection are restarted. The server will treat a subscription as durable. If set to true the client and server will not maintain state across restarts of the client, the server or the connection. This means Message delivery to the specified QOS cannot be maintained if the client, server or connection are restarted The server will treat a subscription as non-durable. true boolean clientId (common) MQTT client identifier. The identifier must be unique. String configuration (common) To use the shared Paho configuration. PahoConfiguration connectionTimeout (common) Sets the connection timeout value. This value, measured in seconds, defines the maximum time interval the client will wait for the network connection to the MQTT server to be established. The default timeout is 30 seconds. A value of 0 disables timeout processing meaning the client will wait until the network connection is made successfully or fails. 30 int filePersistenceDirectory (common) Base directory used by file persistence. Will by default use user directory. String keepAliveInterval (common) Sets the keep alive interval. This value, measured in seconds, defines the maximum time interval between messages sent or received. It enables the client to detect if the server is no longer available, without having to wait for the TCP/IP timeout. The client will ensure that at least one message travels across the network within each keep alive period. In the absence of a data-related message during the time period, the client sends a very small ping message, which the server will acknowledge. A value of 0 disables keepalive processing in the client. The default value is 60 seconds. 60 int maxInflight (common) Sets the max inflight. please increase this value in a high traffic environment. The default value is 10. 10 int maxReconnectDelay (common) Get the maximum time (in millis) to wait between reconnects. 128000 int mqttVersion (common) Sets the MQTT version. The default action is to connect with version 3.1.1, and to fall back to 3.1 if that fails. Version 3.1.1 or 3.1 can be selected specifically, with no fall back, by using the MQTT_VERSION_3_1_1 or MQTT_VERSION_3_1 options respectively. int persistence (common) Client persistence to be used - memory or file. Enum values: FILE MEMORY MEMORY PahoPersistence qos (common) Client quality of service level (0-2). 2 int retained (common) Retain option. false boolean serverURIs (common) Set a list of one or more serverURIs the client may connect to. Multiple servers can be separated by comma. Each serverURI specifies the address of a server that the client may connect to. Two types of connection are supported tcp:// for a TCP connection and ssl:// for a TCP connection secured by SSL/TLS. For example: tcp://localhost:1883 ssl://localhost:8883 If the port is not specified, it will default to 1883 for tcp:// URIs, and 8883 for ssl:// URIs. If serverURIs is set then it overrides the serverURI parameter passed in on the constructor of the MQTT client. When an attempt to connect is initiated the client will start with the first serverURI in the list and work through the list until a connection is established with a server. If a connection cannot be made to any of the servers then the connect attempt fails. Specifying a list of servers that a client may connect to has several uses: High Availability and reliable message delivery Some MQTT servers support a high availability feature where two or more equal MQTT servers share state. An MQTT client can connect to any of the equal servers and be assured that messages are reliably delivered and durable subscriptions are maintained no matter which server the client connects to. The cleansession flag must be set to false if durable subscriptions and/or reliable message delivery is required. Hunt List A set of servers may be specified that are not equal (as in the high availability option). As no state is shared across the servers reliable message delivery and durable subscriptions are not valid. The cleansession flag must be set to true if the hunt list mode is used. String willPayload (common) Sets the Last Will and Testament (LWT) for the connection. In the event that this client unexpectedly loses its connection to the server, the server will publish a message to itself using the supplied details. The topic to publish to The byte payload for the message. The quality of service to publish the message at (0, 1 or 2). Whether or not the message should be retained. String willQos (common) Sets the Last Will and Testament (LWT) for the connection. In the event that this client unexpectedly loses its connection to the server, the server will publish a message to itself using the supplied details. The topic to publish to The byte payload for the message. The quality of service to publish the message at (0, 1 or 2). Whether or not the message should be retained. int willRetained (common) Sets the Last Will and Testament (LWT) for the connection. In the event that this client unexpectedly loses its connection to the server, the server will publish a message to itself using the supplied details. The topic to publish to The byte payload for the message. The quality of service to publish the message at (0, 1 or 2). Whether or not the message should be retained. false boolean willTopic (common) Sets the Last Will and Testament (LWT) for the connection. In the event that this client unexpectedly loses its connection to the server, the server will publish a message to itself using the supplied details. The topic to publish to The byte payload for the message. The quality of service to publish the message at (0, 1 or 2). Whether or not the message should be retained. String bridgeErrorHandler (consumer) Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored. false boolean lazyStartProducer (producer) Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel's routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. false boolean autowiredEnabled (advanced) Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. true boolean client (advanced) To use a shared Paho client. MqttClient customWebSocketHeaders (advanced) Sets the Custom WebSocket Headers for the WebSocket Connection. Properties executorServiceTimeout (advanced) Set the time in seconds that the executor service should wait when terminating before forcefully terminating. It is not recommended to change this value unless you are absolutely sure that you need to. 1 int httpsHostnameVerificationEnabled (security) Whether SSL HostnameVerifier is enabled or not. The default value is true. true boolean password (security) Password to be used for authentication against the MQTT broker. String socketFactory (security) Sets the SocketFactory to use. This allows an application to apply its own policies around the creation of network sockets. If using an SSL connection, an SSLSocketFactory can be used to supply application-specific security settings. SocketFactory sslClientProps (security) Sets the SSL properties for the connection. Note that these properties are only valid if an implementation of the Java Secure Socket Extensions (JSSE) is available. These properties are not used if a custom SocketFactory has been set. The following properties can be used: com.ibm.ssl.protocol One of: SSL, SSLv3, TLS, TLSv1, SSL_TLS. com.ibm.ssl.contextProvider Underlying JSSE provider. For example IBMJSSE2 or SunJSSE com.ibm.ssl.keyStore The name of the file that contains the KeyStore object that you want the KeyManager to use. For example /mydir/etc/key.p12 com.ibm.ssl.keyStorePassword The password for the KeyStore object that you want the KeyManager to use. The password can either be in plain-text, or may be obfuscated using the static method: com.ibm.micro.security.Password.obfuscate(char password). This obfuscates the password using a simple and insecure XOR and Base64 encoding mechanism. Note that this is only a simple scrambler to obfuscate clear-text passwords. com.ibm.ssl.keyStoreType Type of key store, for example PKCS12, JKS, or JCEKS. com.ibm.ssl.keyStoreProvider Key store provider, for example IBMJCE or IBMJCEFIPS. com.ibm.ssl.trustStore The name of the file that contains the KeyStore object that you want the TrustManager to use. com.ibm.ssl.trustStorePassword The password for the TrustStore object that you want the TrustManager to use. The password can either be in plain-text, or may be obfuscated using the static method: com.ibm.micro.security.Password.obfuscate(char password). This obfuscates the password using a simple and insecure XOR and Base64 encoding mechanism. Note that this is only a simple scrambler to obfuscate clear-text passwords. com.ibm.ssl.trustStoreType The type of KeyStore object that you want the default TrustManager to use. Same possible values as keyStoreType. com.ibm.ssl.trustStoreProvider Trust store provider, for example IBMJCE or IBMJCEFIPS. com.ibm.ssl.enabledCipherSuites A list of which ciphers are enabled. Values are dependent on the provider, for example: SSL_RSA_WITH_AES_128_CBC_SHA;SSL_RSA_WITH_3DES_EDE_CBC_SHA. com.ibm.ssl.keyManager Sets the algorithm that will be used to instantiate a KeyManagerFactory object instead of using the default algorithm available in the platform. Example values: IbmX509 or IBMJ9X509. com.ibm.ssl.trustManager Sets the algorithm that will be used to instantiate a TrustManagerFactory object instead of using the default algorithm available in the platform. Example values: PKIX or IBMJ9X509. Properties sslHostnameVerifier (security) Sets the HostnameVerifier for the SSL connection. Note that it will be used after handshake on a connection and you should do actions by yourself when hostname is verified error. There is no default HostnameVerifier. HostnameVerifier userName (security) Username to be used for authentication against the MQTT broker. String 109.5. Endpoint Options The Paho endpoint is configured using URI syntax: with the following path and query parameters: 109.5.1. Path Parameters (1 parameters) Name Description Default Type topic (common) Required Name of the topic. String 109.5.2. Query Parameters (31 parameters) Name Description Default Type automaticReconnect (common) Sets whether the client will automatically attempt to reconnect to the server if the connection is lost. If set to false, the client will not attempt to automatically reconnect to the server in the event that the connection is lost. If set to true, in the event that the connection is lost, the client will attempt to reconnect to the server. It will initially wait 1 second before it attempts to reconnect, for every failed reconnect attempt, the delay will double until it is at 2 minutes at which point the delay will stay at 2 minutes. true boolean brokerUrl (common) The URL of the MQTT broker. tcp://localhost:1883 String cleanSession (common) Sets whether the client and server should remember state across restarts and reconnects. If set to false both the client and server will maintain state across restarts of the client, the server and the connection. As state is maintained: Message delivery will be reliable meeting the specified QOS even if the client, server or connection are restarted. The server will treat a subscription as durable. If set to true the client and server will not maintain state across restarts of the client, the server or the connection. This means Message delivery to the specified QOS cannot be maintained if the client, server or connection are restarted The server will treat a subscription as non-durable. true boolean clientId (common) MQTT client identifier. The identifier must be unique. String connectionTimeout (common) Sets the connection timeout value. This value, measured in seconds, defines the maximum time interval the client will wait for the network connection to the MQTT server to be established. The default timeout is 30 seconds. A value of 0 disables timeout processing meaning the client will wait until the network connection is made successfully or fails. 30 int filePersistenceDirectory (common) Base directory used by file persistence. Will by default use user directory. String keepAliveInterval (common) Sets the keep alive interval. This value, measured in seconds, defines the maximum time interval between messages sent or received. It enables the client to detect if the server is no longer available, without having to wait for the TCP/IP timeout. The client will ensure that at least one message travels across the network within each keep alive period. In the absence of a data-related message during the time period, the client sends a very small ping message, which the server will acknowledge. A value of 0 disables keepalive processing in the client. The default value is 60 seconds. 60 int maxInflight (common) Sets the max inflight. please increase this value in a high traffic environment. The default value is 10. 10 int maxReconnectDelay (common) Get the maximum time (in millis) to wait between reconnects. 128000 int mqttVersion (common) Sets the MQTT version. The default action is to connect with version 3.1.1, and to fall back to 3.1 if that fails. Version 3.1.1 or 3.1 can be selected specifically, with no fall back, by using the MQTT_VERSION_3_1_1 or MQTT_VERSION_3_1 options respectively. int persistence (common) Client persistence to be used - memory or file. Enum values: FILE MEMORY MEMORY PahoPersistence qos (common) Client quality of service level (0-2). 2 int retained (common) Retain option. false boolean serverURIs (common) Set a list of one or more serverURIs the client may connect to. Multiple servers can be separated by comma. Each serverURI specifies the address of a server that the client may connect to. Two types of connection are supported tcp:// for a TCP connection and ssl:// for a TCP connection secured by SSL/TLS. For example: tcp://localhost:1883 ssl://localhost:8883 If the port is not specified, it will default to 1883 for tcp:// URIs, and 8883 for ssl:// URIs. If serverURIs is set then it overrides the serverURI parameter passed in on the constructor of the MQTT client. When an attempt to connect is initiated the client will start with the first serverURI in the list and work through the list until a connection is established with a server. If a connection cannot be made to any of the servers then the connect attempt fails. Specifying a list of servers that a client may connect to has several uses: High Availability and reliable message delivery Some MQTT servers support a high availability feature where two or more equal MQTT servers share state. An MQTT client can connect to any of the equal servers and be assured that messages are reliably delivered and durable subscriptions are maintained no matter which server the client connects to. The cleansession flag must be set to false if durable subscriptions and/or reliable message delivery is required. Hunt List A set of servers may be specified that are not equal (as in the high availability option). As no state is shared across the servers reliable message delivery and durable subscriptions are not valid. The cleansession flag must be set to true if the hunt list mode is used. String willPayload (common) Sets the Last Will and Testament (LWT) for the connection. In the event that this client unexpectedly loses its connection to the server, the server will publish a message to itself using the supplied details. The topic to publish to The byte payload for the message. The quality of service to publish the message at (0, 1 or 2). Whether or not the message should be retained. String willQos (common) Sets the Last Will and Testament (LWT) for the connection. In the event that this client unexpectedly loses its connection to the server, the server will publish a message to itself using the supplied details. The topic to publish to The byte payload for the message. The quality of service to publish the message at (0, 1 or 2). Whether or not the message should be retained. int willRetained (common) Sets the Last Will and Testament (LWT) for the connection. In the event that this client unexpectedly loses its connection to the server, the server will publish a message to itself using the supplied details. The topic to publish to The byte payload for the message. The quality of service to publish the message at (0, 1 or 2). Whether or not the message should be retained. false boolean willTopic (common) Sets the Last Will and Testament (LWT) for the connection. In the event that this client unexpectedly loses its connection to the server, the server will publish a message to itself using the supplied details. The topic to publish to The byte payload for the message. The quality of service to publish the message at (0, 1 or 2). Whether or not the message should be retained. String bridgeErrorHandler (consumer) Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored. false boolean exceptionHandler (consumer (advanced)) To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored. ExceptionHandler exchangePattern (consumer (advanced)) Sets the exchange pattern when the consumer creates an exchange. Enum values: InOnly InOut InOptionalOut ExchangePattern lazyStartProducer (producer) Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel's routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. false boolean client (advanced) To use an existing mqtt client. MqttClient customWebSocketHeaders (advanced) Sets the Custom WebSocket Headers for the WebSocket Connection. Properties executorServiceTimeout (advanced) Set the time in seconds that the executor service should wait when terminating before forcefully terminating. It is not recommended to change this value unless you are absolutely sure that you need to. 1 int httpsHostnameVerificationEnabled (security) Whether SSL HostnameVerifier is enabled or not. The default value is true. true boolean password (security) Password to be used for authentication against the MQTT broker. String socketFactory (security) Sets the SocketFactory to use. This allows an application to apply its own policies around the creation of network sockets. If using an SSL connection, an SSLSocketFactory can be used to supply application-specific security settings. SocketFactory sslClientProps (security) Sets the SSL properties for the connection. Note that these properties are only valid if an implementation of the Java Secure Socket Extensions (JSSE) is available. These properties are not used if a custom SocketFactory has been set. The following properties can be used: com.ibm.ssl.protocol One of: SSL, SSLv3, TLS, TLSv1, SSL_TLS. com.ibm.ssl.contextProvider Underlying JSSE provider. For example IBMJSSE2 or SunJSSE com.ibm.ssl.keyStore The name of the file that contains the KeyStore object that you want the KeyManager to use. For example /mydir/etc/key.p12 com.ibm.ssl.keyStorePassword The password for the KeyStore object that you want the KeyManager to use. The password can either be in plain-text, or may be obfuscated using the static method: com.ibm.micro.security.Password.obfuscate(char password). This obfuscates the password using a simple and insecure XOR and Base64 encoding mechanism. Note that this is only a simple scrambler to obfuscate clear-text passwords. com.ibm.ssl.keyStoreType Type of key store, for example PKCS12, JKS, or JCEKS. com.ibm.ssl.keyStoreProvider Key store provider, for example IBMJCE or IBMJCEFIPS. com.ibm.ssl.trustStore The name of the file that contains the KeyStore object that you want the TrustManager to use. com.ibm.ssl.trustStorePassword The password for the TrustStore object that you want the TrustManager to use. The password can either be in plain-text, or may be obfuscated using the static method: com.ibm.micro.security.Password.obfuscate(char password). This obfuscates the password using a simple and insecure XOR and Base64 encoding mechanism. Note that this is only a simple scrambler to obfuscate clear-text passwords. com.ibm.ssl.trustStoreType The type of KeyStore object that you want the default TrustManager to use. Same possible values as keyStoreType. com.ibm.ssl.trustStoreProvider Trust store provider, for example IBMJCE or IBMJCEFIPS. com.ibm.ssl.enabledCipherSuites A list of which ciphers are enabled. Values are dependent on the provider, for example: SSL_RSA_WITH_AES_128_CBC_SHA;SSL_RSA_WITH_3DES_EDE_CBC_SHA. com.ibm.ssl.keyManager Sets the algorithm that will be used to instantiate a KeyManagerFactory object instead of using the default algorithm available in the platform. Example values: IbmX509 or IBMJ9X509. com.ibm.ssl.trustManager Sets the algorithm that will be used to instantiate a TrustManagerFactory object instead of using the default algorithm available in the platform. Example values: PKIX or IBMJ9X509. Properties sslHostnameVerifier (security) Sets the HostnameVerifier for the SSL connection. Note that it will be used after handshake on a connection and you should do actions by yourself when hostname is verified error. There is no default HostnameVerifier. HostnameVerifier userName (security) Username to be used for authentication against the MQTT broker. String 109.6. Headers The following headers are recognized by the Paho component: Header Java constant Endpoint type Value type Description CamelMqttTopic PahoConstants.MQTT_TOPIC Consumer String The name of the topic CamelMqttQoS PahoConstants.MQTT_QOS Consumer Integer QualityOfService of the incoming message CamelPahoOverrideTopic PahoConstants.CAMEL_PAHO_OVERRIDE_TOPIC Producer String Name of topic to override and send to instead of topic specified on endpoint 109.7. Default payload type By default Camel Paho component operates on the binary payloads extracted out of (or put into) the MQTT message: // Receive payload byte[] payload = (byte[]) consumerTemplate.receiveBody("paho:topic"); // Send payload byte[] payload = "message".getBytes(); producerTemplate.sendBody("paho:topic", payload); But of course Camel build-in type conversion API can perform the automatic data type transformations for you. In the example below Camel automatically converts binary payload into String (and conversely): // Receive payload String payload = consumerTemplate.receiveBody("paho:topic", String.class); // Send payload String payload = "message"; producerTemplate.sendBody("paho:topic", payload); 109.8. Samples For example the following snippet reads messages from the MQTT broker installed on the same host as the Camel router: from("paho:some/queue") .to("mock:test"); While the snippet below sends message to the MQTT broker: from("direct:test") .to("paho:some/target/queue"); For example this is how to read messages from the remote MQTT broker: from("paho:some/queue?brokerUrl=tcp://iot.eclipse.org:1883") .to("mock:test"); And here we override the default topic and set to a dynamic topic from("direct:test") .setHeader(PahoConstants.CAMEL_PAHO_OVERRIDE_TOPIC, simple("USD{header.customerId}")) .to("paho:some/target/queue"); 109.9. Spring Boot Auto-Configuration The component supports 32 options, which are listed below. Name Description Default Type camel.component.paho.automatic-reconnect Sets whether the client will automatically attempt to reconnect to the server if the connection is lost. If set to false, the client will not attempt to automatically reconnect to the server in the event that the connection is lost. If set to true, in the event that the connection is lost, the client will attempt to reconnect to the server. It will initially wait 1 second before it attempts to reconnect, for every failed reconnect attempt, the delay will double until it is at 2 minutes at which point the delay will stay at 2 minutes. true Boolean camel.component.paho.autowired-enabled Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. true Boolean camel.component.paho.bridge-error-handler Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored. false Boolean camel.component.paho.broker-url The URL of the MQTT broker. tcp://localhost:1883 String camel.component.paho.clean-session Sets whether the client and server should remember state across restarts and reconnects. If set to false both the client and server will maintain state across restarts of the client, the server and the connection. As state is maintained: Message delivery will be reliable meeting the specified QOS even if the client, server or connection are restarted. The server will treat a subscription as durable. If set to true the client and server will not maintain state across restarts of the client, the server or the connection. This means Message delivery to the specified QOS cannot be maintained if the client, server or connection are restarted The server will treat a subscription as non-durable. true Boolean camel.component.paho.client To use a shared Paho client. The option is a org.eclipse.paho.client.mqttv3.MqttClient type. MqttClient camel.component.paho.client-id MQTT client identifier. The identifier must be unique. String camel.component.paho.configuration To use the shared Paho configuration. The option is a org.apache.camel.component.paho.PahoConfiguration type. PahoConfiguration camel.component.paho.connection-timeout Sets the connection timeout value. This value, measured in seconds, defines the maximum time interval the client will wait for the network connection to the MQTT server to be established. The default timeout is 30 seconds. A value of 0 disables timeout processing meaning the client will wait until the network connection is made successfully or fails. 30 Integer camel.component.paho.custom-web-socket-headers Sets the Custom WebSocket Headers for the WebSocket Connection. The option is a java.util.Properties type. Properties camel.component.paho.enabled Whether to enable auto configuration of the paho component. This is enabled by default. Boolean camel.component.paho.executor-service-timeout Set the time in seconds that the executor service should wait when terminating before forcefully terminating. It is not recommended to change this value unless you are absolutely sure that you need to. 1 Integer camel.component.paho.file-persistence-directory Base directory used by file persistence. Will by default use user directory. String camel.component.paho.https-hostname-verification-enabled Whether SSL HostnameVerifier is enabled or not. The default value is true. true Boolean camel.component.paho.keep-alive-interval Sets the keep alive interval. This value, measured in seconds, defines the maximum time interval between messages sent or received. It enables the client to detect if the server is no longer available, without having to wait for the TCP/IP timeout. The client will ensure that at least one message travels across the network within each keep alive period. In the absence of a data-related message during the time period, the client sends a very small ping message, which the server will acknowledge. A value of 0 disables keepalive processing in the client. The default value is 60 seconds. 60 Integer camel.component.paho.lazy-start-producer Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel's routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. false Boolean camel.component.paho.max-inflight Sets the max inflight. please increase this value in a high traffic environment. The default value is 10. 10 Integer camel.component.paho.max-reconnect-delay Get the maximum time (in millis) to wait between reconnects. 128000 Integer camel.component.paho.mqtt-version Sets the MQTT version. The default action is to connect with version 3.1.1, and to fall back to 3.1 if that fails. Version 3.1.1 or 3.1 can be selected specifically, with no fall back, by using the MQTT_VERSION_3_1_1 or MQTT_VERSION_3_1 options respectively. Integer camel.component.paho.password Password to be used for authentication against the MQTT broker. String camel.component.paho.persistence Client persistence to be used - memory or file. PahoPersistence camel.component.paho.qos Client quality of service level (0-2). 2 Integer camel.component.paho.retained Retain option. false Boolean camel.component.paho.server-u-r-is Set a list of one or more serverURIs the client may connect to. Multiple servers can be separated by comma. Each serverURI specifies the address of a server that the client may connect to. Two types of connection are supported tcp:// for a TCP connection and ssl:// for a TCP connection secured by SSL/TLS. For example: tcp://localhost:1883 ssl://localhost:8883 If the port is not specified, it will default to 1883 for tcp:// URIs, and 8883 for ssl:// URIs. If serverURIs is set then it overrides the serverURI parameter passed in on the constructor of the MQTT client. When an attempt to connect is initiated the client will start with the first serverURI in the list and work through the list until a connection is established with a server. If a connection cannot be made to any of the servers then the connect attempt fails. Specifying a list of servers that a client may connect to has several uses: High Availability and reliable message delivery Some MQTT servers support a high availability feature where two or more equal MQTT servers share state. An MQTT client can connect to any of the equal servers and be assured that messages are reliably delivered and durable subscriptions are maintained no matter which server the client connects to. The cleansession flag must be set to false if durable subscriptions and/or reliable message delivery is required. Hunt List A set of servers may be specified that are not equal (as in the high availability option). As no state is shared across the servers reliable message delivery and durable subscriptions are not valid. The cleansession flag must be set to true if the hunt list mode is used. String camel.component.paho.socket-factory Sets the SocketFactory to use. This allows an application to apply its own policies around the creation of network sockets. If using an SSL connection, an SSLSocketFactory can be used to supply application-specific security settings. The option is a javax.net.SocketFactory type. SocketFactory camel.component.paho.ssl-client-props Sets the SSL properties for the connection. Note that these properties are only valid if an implementation of the Java Secure Socket Extensions (JSSE) is available. These properties are not used if a custom SocketFactory has been set. The following properties can be used: com.ibm.ssl.protocol One of: SSL, SSLv3, TLS, TLSv1, SSL_TLS. com.ibm.ssl.contextProvider Underlying JSSE provider. For example IBMJSSE2 or SunJSSE com.ibm.ssl.keyStore The name of the file that contains the KeyStore object that you want the KeyManager to use. For example /mydir/etc/key.p12 com.ibm.ssl.keyStorePassword The password for the KeyStore object that you want the KeyManager to use. The password can either be in plain-text, or may be obfuscated using the static method: com.ibm.micro.security.Password.obfuscate(char password). This obfuscates the password using a simple and insecure XOR and Base64 encoding mechanism. Note that this is only a simple scrambler to obfuscate clear-text passwords. com.ibm.ssl.keyStoreType Type of key store, for example PKCS12, JKS, or JCEKS. com.ibm.ssl.keyStoreProvider Key store provider, for example IBMJCE or IBMJCEFIPS. com.ibm.ssl.trustStore The name of the file that contains the KeyStore object that you want the TrustManager to use. com.ibm.ssl.trustStorePassword The password for the TrustStore object that you want the TrustManager to use. The password can either be in plain-text, or may be obfuscated using the static method: com.ibm.micro.security.Password.obfuscate(char password). This obfuscates the password using a simple and insecure XOR and Base64 encoding mechanism. Note that this is only a simple scrambler to obfuscate clear-text passwords. com.ibm.ssl.trustStoreType The type of KeyStore object that you want the default TrustManager to use. Same possible values as keyStoreType. com.ibm.ssl.trustStoreProvider Trust store provider, for example IBMJCE or IBMJCEFIPS. com.ibm.ssl.enabledCipherSuites A list of which ciphers are enabled. Values are dependent on the provider, for example: SSL_RSA_WITH_AES_128_CBC_SHA;SSL_RSA_WITH_3DES_EDE_CBC_SHA. com.ibm.ssl.keyManager Sets the algorithm that will be used to instantiate a KeyManagerFactory object instead of using the default algorithm available in the platform. Example values: IbmX509 or IBMJ9X509. com.ibm.ssl.trustManager Sets the algorithm that will be used to instantiate a TrustManagerFactory object instead of using the default algorithm available in the platform. Example values: PKIX or IBMJ9X509. The option is a java.util.Properties type. Properties camel.component.paho.ssl-hostname-verifier Sets the HostnameVerifier for the SSL connection. Note that it will be used after handshake on a connection and you should do actions by yourself when hostname is verified error. There is no default HostnameVerifier. The option is a javax.net.ssl.HostnameVerifier type. HostnameVerifier camel.component.paho.user-name Username to be used for authentication against the MQTT broker. String camel.component.paho.will-payload Sets the Last Will and Testament (LWT) for the connection. In the event that this client unexpectedly loses its connection to the server, the server will publish a message to itself using the supplied details. The topic to publish to The byte payload for the message. The quality of service to publish the message at (0, 1 or 2). Whether or not the message should be retained. String camel.component.paho.will-qos Sets the Last Will and Testament (LWT) for the connection. In the event that this client unexpectedly loses its connection to the server, the server will publish a message to itself using the supplied details. The topic to publish to The byte payload for the message. The quality of service to publish the message at (0, 1 or 2). Whether or not the message should be retained. Integer camel.component.paho.will-retained Sets the Last Will and Testament (LWT) for the connection. In the event that this client unexpectedly loses its connection to the server, the server will publish a message to itself using the supplied details. The topic to publish to The byte payload for the message. The quality of service to publish the message at (0, 1 or 2). Whether or not the message should be retained. false Boolean camel.component.paho.will-topic Sets the Last Will and Testament (LWT) for the connection. In the event that this client unexpectedly loses its connection to the server, the server will publish a message to itself using the supplied details. The topic to publish to The byte payload for the message. The quality of service to publish the message at (0, 1 or 2). Whether or not the message should be retained. String

Commands:
<dependency> <groupId>org.apache.camel.springboot</groupId> <artifactId>camel-paho-starter</artifactId> </dependency>
paho:topic[?options]
paho:topic
// Receive payload byte[] payload = (byte[]) consumerTemplate.receiveBody("paho:topic"); // Send payload byte[] payload = "message".getBytes(); producerTemplate.sendBody("paho:topic", payload);
// Receive payload String payload = consumerTemplate.receiveBody("paho:topic", String.class); // Send payload String payload = "message"; producerTemplate.sendBody("paho:topic", payload);
from("paho:some/queue") .to("mock:test");
from("direct:test") .to("paho:some/target/queue");
from("paho:some/queue?brokerUrl=tcp://iot.eclipse.org:1883") .to("mock:test");
from("direct:test") .setHeader(PahoConstants.CAMEL_PAHO_OVERRIDE_TOPIC, simple("USD{header.customerId}")) .to("paho:some/target/queue");