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本文主要研究一下openmessaging的MessagingAccessPoint
MessagingAccessPoint
openmessaging-java/openmessaging-api/src/main/java/io/openmessaging/MessagingAccessPoint.java
/**
* An instance of {@code MessagingAccessPoint} may be obtained from {@link OMS}, which is capable of creating {@code
* Producer}, {@code Consumer}, {@code ResourceManager}, and other facility entities.
*
* For example:
*
* MessagingAccessPoint messagingAccessPoint = OMS.getMessagingAccessPoint("oms:rocketmq://[email protected]/us-east:default_space");
* messagingAccessPoint.startup();
* Producer producer = messagingAccessPoint.createProducer();
* producer.startup();
* producer.send(producer.createBytesMessage("HELLO_QUEUE", "HELLO_BODY".getBytes(Charset.forName("UTF-8"))));
*
*
* @version OMS 1.0.0
* @since OMS 1.0.0
*/
public interface MessagingAccessPoint extends ServiceLifecycle {
/**
* Returns the target OMS specification version of the specified vendor implementation.
*
* @return the OMS version of implementation
* @see OMS#specVersion
*/
String implVersion();
/**
* Returns the attributes of this {@code MessagingAccessPoint} instance.
*
* There are some standard attributes defined by OMS for {@code MessagingAccessPoint}:
*
* - {@link OMSBuiltinKeys#ACCESS_POINTS}, the specified access points.
*
- {@link OMSBuiltinKeys#DRIVER_IMPL}, the fully qualified class name of the specified MessagingAccessPoint's
* implementation, the default value is {@literal io.openmessaging.
.MessagingAccessPointImpl}.
* - {@link OMSBuiltinKeys#REGION}, the region the resources reside in.
*
- {@link OMSBuiltinKeys#ACCOUNT_ID}, the ID of the specific account system that owns the resource.
*
*
* @return the attributes
*/
KeyValue attributes();
/**
* Creates a new {@code Producer} for the specified {@code MessagingAccessPoint}.
*
* @return the created {@code Producer}
* @throws OMSRuntimeException if the {@code MessagingAccessPoint} fails to handle this request
* due to some internal error
*/
Producer createProducer();
/**
* Creates a new {@code Producer} for the specified {@code MessagingAccessPoint}
* with some preset attributes.
*
* @param attributes the preset attributes
* @return the created {@code Producer}
* @throws OMSRuntimeException if the {@code MessagingAccessPoint} fails to handle this request
* due to some internal error
*/
Producer createProducer(KeyValue attributes);
/**
* Creates a new {@code PushConsumer} for the specified {@code MessagingAccessPoint}.
* The returned {@code PushConsumer} isn't attached to any queue,
* uses {@link PushConsumer#attachQueue(String, MessageListener)} to attach queues.
*
* @return the created {@code PushConsumer}
* @throws OMSRuntimeException if the {@code MessagingAccessPoint} fails to handle this request
* due to some internal error
*/
PushConsumer createPushConsumer();
/**
* Creates a new {@code PushConsumer} for the specified {@code MessagingAccessPoint} with some preset attributes.
*
* @param attributes the preset attributes
* @return the created {@code PushConsumer}
* @throws OMSRuntimeException if the {@code MessagingAccessPoint} fails to handle this request
* due to some internal error
*/
PushConsumer createPushConsumer(KeyValue attributes);
/**
* Creates a new {@code PullConsumer} for the specified {@code MessagingAccessPoint}.
*
* @return the created {@code PullConsumer}
* @throws OMSRuntimeException if the {@code MessagingAccessPoint} fails to handle this request
* due to some internal error
*/
PullConsumer createPullConsumer();
/**
* Creates a new {@code PullConsumer} for the specified {@code MessagingAccessPoint} with some preset attributes.
*
* @param attributes the preset attributes
* @return the created {@code PullConsumer}
* @throws OMSRuntimeException if the {@code MessagingAccessPoint} fails to handle this request
* due to some internal error
*/
PullConsumer createPullConsumer(KeyValue attributes);
/**
* Creates a new {@code StreamingConsumer} for the specified {@code MessagingAccessPoint}.
*
* @return the created {@code Stream}
* @throws OMSRuntimeException if the {@code MessagingAccessPoint} fails to handle this request
* due to some internal error
*/
StreamingConsumer createStreamingConsumer();
/**
* Creates a new {@code StreamingConsumer} for the specified {@code MessagingAccessPoint} with some preset
* attributes.
*
* @param attributes the preset attributes
* @return the created consumer
* @throws OMSRuntimeException if the {@code MessagingAccessPoint} fails to handle this request
* due to some internal error
*/
StreamingConsumer createStreamingConsumer(KeyValue attributes);
/**
* Gets a lightweight {@code ResourceManager} instance from the specified {@code MessagingAccessPoint}.
*
* @return the resource manger
* @throws OMSRuntimeException if the {@code MessagingAccessPoint} fails to handle this request
* due to some internal error
*/
ResourceManager resourceManager();
}- MessagingAccessPoint就类似OMS的工厂方法，聚合了创建各类对象的方法，比如createProducer，createPushConsumer，createPullConsumer，resourceManager
OMS
openmessaging-java/openmessaging-api/src/main/java/io/openmessaging/OMS.java
/**
* The oms class provides some static methods to create a {@code MessagingAccessPoint}
* from the specified OMS driver url and some useful util methods.
*
* The complete OMS driver URL syntax is:
*
* {@literal oms:://[account_id@]host1[:port1][,host2[:port2],...[,hostN[:portN]]]/}
*
* The first part of the URL specifies which OMS implementation is to be used, rocketmq is a
* optional driver type.
*
* The brackets indicate that the extra access points are optional, and a correct OMS driver url
* needs at least one access point, which consists of hostname and port, like localhost:8081.
*
* @version OMS 1.0.0
* @see ResourceManager
* @since OMS 1.0.0
*/
public final class OMS {
/**
* Returns a {@code MessagingAccessPoint} instance from the specified OMS driver url.
*
* @param url the specified OMS driver url
* @return a {@code MessagingAccessPoint} instance
* @throws OMSRuntimeException if the factory fails to create a {@code MessagingAccessPoint} due to some driver url
* some syntax error or internal error.
*/
public static MessagingAccessPoint getMessagingAccessPoint(String url) {
return getMessagingAccessPoint(url, OMS.newKeyValue());
}
/**
* Returns a {@code MessagingAccessPoint} instance from the specified OMS driver url
* with some preset attributes, which will be passed to MessagingAccessPoint's implementation
* class as a unique constructor parameter.
*
* There are some standard attributes defined by OMS for this method,
* the same as {@link MessagingAccessPoint#attributes()}
*
* @param url the specified OMS driver url
* @return a {@code MessagingAccessPoint} instance
* @throws OMSRuntimeException if the factory fails to create a {@code MessagingAccessPoint} due to some driver url
* some syntax error or internal error.
*/
public static MessagingAccessPoint getMessagingAccessPoint(String url, KeyValue attributes) {
return MessagingAccessPointAdapter.getMessagingAccessPoint(url, attributes);
}
/**
* Returns a default and internal {@code KeyValue} implementation instance.
*
* @return a {@code KeyValue} instance
*/
public static KeyValue newKeyValue() {
return new DefaultKeyValue();
}
/**
* The version format is X.Y.Z (Major.Minor.Patch), a pre-release version may be denoted by appending a hyphen and a
* series of dot-separated identifiers immediately following the patch version, like X.Y.Z-alpha.
*
*
* OMS version follows semver scheme partially.
*
* @see http://semver.org
*/
public static String specVersion = "UnKnown";
static {
InputStream stream = OMS.class.getClassLoader().getResourceAsStream("oms.spec.properties");
try {
if (stream != null) {
Properties properties = new Properties();
properties.load(stream);
specVersion = String.valueOf(properties.get("version"));
}
} catch (IOException ignore) {
}
}
private OMS() {
}
}
- OMS可以理解为总入口，是MessagingAccessPoint的静态工厂方法
- 它根据url来解析访问地址等信息，比如oms:rocketmq://[email protected]/us-east:default_space
ResourceManager
openmessaging-java/openmessaging-api/src/main/java/io/openmessaging/ResourceManager.java
/**
* The {@code ResourceManager} is to provide a unified interface of resource management,
* allowing developers to manage the namespace, queue and routing resources.
*
* Create, set, get and delete are the four basic operations of {@code ResourceManager}.
*
* {@code ResourceManager} also supports dynamic fetch and update of resource attributes.
*
* {@link MessagingAccessPoint#resourceManager()} ()} is the unique method to obtain a {@code ResourceManager}
* instance. Changes made through this instance will immediately apply to the message-oriented middleware (MOM) behind
* {@code MessagingAccessPoint}.
*
* @version OMS 1.0.0
* @since OMS 1.0.0
*/
public interface ResourceManager {
/**
* Creates a {@code Namespace} resource with some preset attributes.
*
* A namespace wraps the OMS resources in an abstract concept that makes it appear to the users
* within the namespace that they have their own isolated instance of the global OMS resources.
*
* @param nsName the name of the new namespace
* @param attributes the preset attributes
*/
void createNamespace(String nsName, KeyValue attributes);
/**
* Sets the attributes of the specific namespace, the old attributes will be replaced
* by the provided attributes, only the provided key will be updated.
*
* @param nsName the specific namespace
* @param attributes the new attributes
* @throws OMSResourceNotExistException if the specific namespace does not exist
*/
void setNamespaceAttributes(String nsName, KeyValue attributes) throws OMSResourceNotExistException;
/**
* Gets the attributes of the specific namespace.
*
* @param nsName the specific namespace
* @return the attributes of namespace
* @throws OMSResourceNotExistException if the specific namespace does not exist
*/
KeyValue getNamespaceAttributes(String nsName) throws OMSResourceNotExistException;
/**
* Deletes an existing namespace resource.
*
* @param nsName the namespace needs to be deleted
* @throws OMSResourceNotExistException if the specified namespace does not exist
*/
void deleteNamespace(String nsName) throws OMSResourceNotExistException;
/**
* Gets the namespace list in the current {@code MessagingAccessPoint}.
*
* @return the list of all namespaces
*/
List listNamespaces();
/**
* Creates a {@code Queue} resource in the configured namespace with some preset attributes.
*
* The standard OMS {@code Queue} schema must start with the {@code Namespace} prefix:
*
* {@literal ://}
*
* @param queueName the name of the new queue
* @param attributes the preset attributes
* @throws OMSResourceNotExistException if the configured namespace does not exist or specified queue name is
* not available
*/
void createQueue(String queueName, KeyValue attributes) throws OMSResourceNotExistException;
/**
* Sets the attributes of the specified queue, the old attributes will be replaced
* by the provided attributes, only the provided key will be updated.
*
* @param queueName the queue name
* @param attributes the new attributes
* @throws OMSResourceNotExistException if the specified queue or namespace does not exist
*/
void setQueueAttributes(String queueName, KeyValue attributes) throws OMSResourceNotExistException;
/**
* Gets the attributes of the specified queue.
*
* @param queueName the queue name
* @return the attributes of namespace
* @throws OMSResourceNotExistException if the specified queue or namespace does not exist
*/
KeyValue getQueueAttributes(String queueName) throws OMSResourceNotExistException;
/**
* Deletes an existing queue resource.
*
* @param queueName the queue needs to be deleted
* @throws OMSResourceNotExistException if the specified queue or namespace does not exist
*/
void deleteQueue(String queueName) throws OMSResourceNotExistException;
/**
* Gets the queue list in the specific namespace.
*
* @param nsName the specific namespace
* @return the list of all queues
* @throws OMSResourceNotExistException if the specific namespace does not exist
*/
List listQueues(String nsName) throws OMSResourceNotExistException;
/**
* Creates a {@code Routing} resource in the configured namespace with some preset attributes.
*
* The standard OMS {@code Routing} schema must start with the {@code Namespace} prefix:
*
* {@literal ://}
*
* @param routingName the name of the new routing
* @param attributes the preset attributes
* @throws OMSResourceNotExistException if the configured namespace does not exist or specified routing name is not
* available
*/
void createRouting(String routingName, KeyValue attributes) throws OMSResourceNotExistException;
/**
* Sets the attributes of the specified routing, the old attributes will be replaced
* by the provided attributes, only the provided key will be updated.
*
* @param routingName the routing name
* @param attributes the new attributes
* @throws OMSResourceNotExistException if the specified routing or namespace does not exist
*/
void setRoutingAttributes(String routingName, KeyValue attributes) throws OMSResourceNotExistException;
/**
* Gets the attributes of the specified routing.
*
* @param routingName the routing name
* @return the attributes of routing
* @throws OMSResourceNotExistException if the specified routing or namespace does not exist
*/
KeyValue getRoutingAttributes(String routingName) throws OMSResourceNotExistException;
/**
* Deletes an existing routing resource.
*
* @param routingName the routing needs to be deleted
* @throws OMSResourceNotExistException if the specified routing or namespace does not exist
*/
void deleteRouting(String routingName) throws OMSResourceNotExistException;
/**
* Gets the routing list in the specific namespace.
*
* @param nsName the specific namespace
* @return the list of all routings
* @throws OMSResourceNotExistException if the specific namespace does not exist
*/
List listRoutings(String nsName) throws OMSResourceNotExistException;
/**
* Gets the stream list behind the specified queue.
*
* @param queueName the queue name
* @return the list of all streams
* @throws OMSResourceNotExistException if the specified queue or namespace does not exist
*/
List listStreams(String queueName) throws OMSResourceNotExistException;
/**
* Updates some system headers of a message in the configured namespace.
*
* Below system headers are allowed to be changed dynamically:
*
* - {@link Message.BuiltinKeys#START_TIME}
* - {@link Message.BuiltinKeys#STOP_TIME}
* - {@link Message.BuiltinKeys#TIMEOUT}
* - {@link Message.BuiltinKeys#PRIORITY}
* - {@link Message.BuiltinKeys#SCHEDULE_EXPRESSION}
*
*
* @param queueName the specific queue the message resides in
* @param messageId the id of message
* @param headers the new headers
* @throws OMSResourceNotExistException if the specified queue, namespace or message does not exist
*/
void updateMessage(String queueName, String messageId, KeyValue headers) throws OMSResourceNotExistException;
}
- 提供了namespace、queue、routing等的操作方法
- namespace相关的操作有createNamespace、setNamespaceAttributes、deleteNamespace、listNamespaces、getNamespaceAttributes
- queue相关的操作有createQueue、setQueueAttributes、getQueueAttributes、deleteQueue、listQueues
- routing相关的操作有createRouting、setRoutingAttributes、getRoutingAttributes、deleteRouting、listRoutings
- 通过也提供了listStreams以及updateMessage方法
小结
openmessaging的MessagingAccessPoint聚合了相关访问操作入口，可以理解为一个facade，另外OMS是MessagingAccessPoint的静态工厂，而ResourceManager则类似kafkaAdmin，用于操作管理namespace、queue、routing等。
doc
- openmessaging.cloud
- OpenMessaging Runtime Interface for Java