ros

Class Publisher

java.lang.Object

ros.Publisher

public class Publisher
extends Object

A wrapper class for streamlining ROS Topic publishing. Note that the advertise() never *needs* to be explicitly called. If you use the standard Publisher(String, String, RosBridge) method, it will be automatically called on construction and if you use the Publisher(String, String, RosBridge, boolean) method and set the advertiseNow flag to false, you still don't *need* to call it, because the first publish will automatically make sure the topic has been advertised first.

Publish messages using the publish(Object) method. It takes an object containing the ROS message to publish. Generally, the msg should either be a Javabean, such as one of the pre-included messages in the ros.msgs package that has the same field structure as the target topic type or a Map object representing the ROS message type structure. For example, if the ROS message type is "std_msgs/String" then msg should be a PrimitiveMsg with the generic of String, or a Map object with one Map key-value entry of "data: stringValue" where stringValue is whatever the "std_msgs/String" data field value is.

Author:

James MacGlashan.

Field Summary

Fields

Modifier and Type	Field and Description
protected String	msgType
protected RosBridge	rosBridge
protected String	topic

Constructor Summary

Constructors

Constructor and Description
Publisher(String topic, String msgType, RosBridge rosBridge) Constructs and automatically advertises publishing to this topic.
Publisher(String topic, String msgType, RosBridge rosBridge, boolean advertiseNow) Constructs and advertises if the advertiseNow flag is set to true.

Method Summary

Modifier and Type	Method and Description
void	advertise() Advertises to ROS that this topic will have messages published to it.
String	getMsgType() Returns the ROS message type of the topic to which this object publishes.
RosBridge	getRosBridge() Returns the RosBridge object that manages the connection to the ROS Bridge server.
String	getTopic() Returns the topic topic to which this object publishes.
void	publish(Object msg) Publishes the message.
void	publishJsonMsg(String jsonMsg) Publishes a ROS message specified in a JSON string.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

topic

protected String topic

msgType

protected String msgType

rosBridge

protected RosBridge rosBridge

Constructor Detail

Publisher

public Publisher(String topic,
                 String msgType,
                 RosBridge rosBridge)

Constructs and automatically advertises publishing to this topic.

Parameters:

topic - the topic to which messages will be published

msgType - the ROS message type of the topic

rosBridge - the RosBridge that manages ROS Bridge interactions.

Publisher

public Publisher(String topic,
                 String msgType,
                 RosBridge rosBridge,
                 boolean advertiseNow)

Constructs and advertises if the advertiseNow flag is set to true.

Parameters:

topic - the topic to which messages will be published

msgType - the ROS message type of the topic

rosBridge - the RosBridge that manages ROS Bridge interactions.

advertiseNow - if true, then the topic is advertised; if false then it is not yet advertised.

Method Detail

advertise

public void advertise()

Advertises to ROS that this topic will have messages published to it. You never *need* to call this method since publishes will always make sure it was advertised first, but gives you control if you did not have the topic advertised at constructions.

publish

public void publish(Object msg)

Publishes the message. If this client is not already advertising for this topic, it automatically will first.

Generally, the msg should either be a Javabean, such as one of the pre-included messages in the ros.msgs package that has the same field structure as the target topic type or a Map object representing the ROS message type structure. For example, if the ROS message type is "std_msgs/String" then msg should be a PrimitiveMsg with the generic of String, or a Map object with one Map key-value entry of "data: stringValue" where stringValue is whatever the "std_msgs/String" data field value is.

Parameters:

msg - the message to publish.

publishJsonMsg

public void publishJsonMsg(String jsonMsg)

Publishes a ROS message specified in a JSON string. If this client is not already advertising for this topic, it automatically will first.

Parameters:

jsonMsg - the ROS message specified in a JSON string.

getTopic

public String getTopic()

Returns the topic topic to which this object publishes.

Returns:

the topic topic to which this object publishes.

getMsgType

public String getMsgType()

Returns the ROS message type of the topic to which this object publishes.

Returns:

the ROS message type of the topic to which this object publishes.

getRosBridge

public RosBridge getRosBridge()

Returns the RosBridge object that manages the connection to the ROS Bridge server.

Returns:

the RosBridge object that manages the connection to the ROS Bridge server.