ServiceBroker (moleculer-java 1.2.21 API)

java.lang.Object
- services.moleculer.context.ContextSource
- - services.moleculer.ServiceBroker

All Implemented Interfaces:

MetricConstants
```
public class ServiceBroker
extends ContextSource
implements MetricConstants
```
The ServiceBroker is the main component of Moleculer. It handles services & events, calls actions and communicates with remote nodes. You need to create an instance of ServiceBroker for every node. Features of Moleculer:
- Fast - High-performance and non-blocking
- Polyglot - Moleculer is implemented under Node.js and Java
- Extensible - All built-in modules (caching, serializer, transporter) are pluggable
- Open source - Moleculer is 100% open source and free of charge
- Fault tolerant - With built-in load balancer & circuit breaker
Sample of usage:
```
 ServiceBroker broker = new ServiceBroker("node-1");

 broker.createService(new Service("math") {
        Action add = ctx -> {
                return ctx.params.get("a").asInteger() + ctx.params.get("b").asInteger();
        };
 });

 broker.start();

 broker.call("math.add", "a", 5, "b", 3).then(rsp -> {
        broker.getLogger().info("Response: " + rsp.asInteger());
 });
 
```
This project is based on the idea of Moleculer Microservices Framework for Node.js (https://moleculer.services). Special thanks to the Moleculer's project owner (https://github.com/icebob) for the consultations.

Field Summary

Fields
Modifier and Type	Field and Description
`protected ServiceBrokerConfig`	`config` Configuration settings and internal components (event bus, cacher, service registry, etc.) of this node / broker.
`protected static org.slf4j.Logger`	`logger` SLF4J logger of this class.
`protected java.util.LinkedHashSet<Middleware>`	`middlewares` Middlewares which defined and added to the Broker before the boot process.
`protected java.util.LinkedHashSet<java.lang.String>`	`serviceNames` Service names (keys).
`protected ServiceRegistry`	`serviceRegistry` Implementation of the service registry of the current node.
`protected java.util.concurrent.ConcurrentHashMap<java.lang.String,Service>`	`services` Services which defined and added to the Broker before the boot process.
`static java.lang.String`	`SOFTWARE_VERSION` Version of the Java ServiceBroker API.
`protected StrategyFactory`	`strategyFactory` Default (round-robin) service invocation factory.
`protected Transporter`	`transporter` Implementation of the Transporter.

Fields inherited from class services.moleculer.context.ContextSource
eventbus, nodeID, serviceInvoker, uidGenerator

Fields inherited from interface services.moleculer.metrics.MetricConstants
MOLECULER_CACHER_CLEAN_TIME, MOLECULER_CACHER_CLEAN_TIME_DESC, MOLECULER_CACHER_CLEAN_TOTAL, MOLECULER_CACHER_CLEAN_TOTAL_DESC, MOLECULER_CACHER_DEL_TIME, MOLECULER_CACHER_DEL_TIME_DESC, MOLECULER_CACHER_DEL_TOTAL, MOLECULER_CACHER_DEL_TOTAL_DESC, MOLECULER_CACHER_EXPIRED_TOTAL, MOLECULER_CACHER_EXPIRED_TOTAL_DESC, MOLECULER_CACHER_FOUND_TOTAL, MOLECULER_CACHER_FOUND_TOTAL_DESC, MOLECULER_CACHER_GET_TIME, MOLECULER_CACHER_GET_TIME_DESC, MOLECULER_CACHER_GET_TOTAL, MOLECULER_CACHER_GET_TOTAL_DESC, MOLECULER_CACHER_SET_TIME, MOLECULER_CACHER_SET_TIME_DESC, MOLECULER_CACHER_SET_TOTAL, MOLECULER_CACHER_SET_TOTAL_DESC, MOLECULER_CIRCUIT_BREAKER_HALF_OPENED_ACTIVE, MOLECULER_CIRCUIT_BREAKER_HALF_OPENED_ACTIVE_DESC, MOLECULER_CIRCUIT_BREAKER_OPENED_ACTIVE, MOLECULER_CIRCUIT_BREAKER_OPENED_ACTIVE_DESC, MOLECULER_CIRCUIT_BREAKER_OPENED_TOTAL, MOLECULER_CIRCUIT_BREAKER_OPENED_TOTAL_DESC, MOLECULER_EVENT_BROADCAST_TOTAL, MOLECULER_EVENT_BROADCAST_TOTAL_DESC, MOLECULER_EVENT_BROADCASTLOCAL_TOTAL, MOLECULER_EVENT_BROADCASTLOCAL_TOTAL_DESC, MOLECULER_EVENT_EMIT_TOTAL, MOLECULER_EVENT_EMIT_TOTAL_DESC, MOLECULER_EVENT_RECEIVED_ACTIVE, MOLECULER_EVENT_RECEIVED_ACTIVE_DESC, MOLECULER_EVENT_RECEIVED_ERROR_TOTAL, MOLECULER_EVENT_RECEIVED_ERROR_TOTAL_DESC, MOLECULER_EVENT_RECEIVED_TIME, MOLECULER_EVENT_RECEIVED_TIME_DESC, MOLECULER_EVENT_RECEIVED_TOTAL, MOLECULER_EVENT_RECEIVED_TOTAL_DESC, MOLECULER_EXECUTOR, MOLECULER_REQUEST_ACTIVE, MOLECULER_REQUEST_ACTIVE_DESC, MOLECULER_REQUEST_ERROR_TOTAL, MOLECULER_REQUEST_ERROR_TOTAL_DESC, MOLECULER_REQUEST_LEVELS, MOLECULER_REQUEST_LEVELS_DESC, MOLECULER_REQUEST_RETRY_ATTEMPTS_TOTAL, MOLECULER_REQUEST_RETRY_ATTEMPTS_TOTAL_DESC, MOLECULER_REQUEST_TIME, MOLECULER_REQUEST_TIME_DESC, MOLECULER_REQUEST_TIMEOUT_TOTAL, MOLECULER_REQUEST_TIMEOUT_TOTAL_DESC, MOLECULER_REQUEST_TOTAL, MOLECULER_REQUEST_TOTAL_DESC, MOLECULER_SCHEDULER, MOLECULER_TRANSIT_CONNECTED, MOLECULER_TRANSIT_CONNECTED_DESC, MOLECULER_TRANSIT_ORPHAN_RESPONSE_TOTAL, MOLECULER_TRANSIT_ORPHAN_RESPONSE_TOTAL_DESC, MOLECULER_TRANSIT_REQUESTS_ACTIVE, MOLECULER_TRANSIT_REQUESTS_ACTIVE_DESC, MOLECULER_TRANSIT_STREAMS_RECEIVE_ACTIVE, MOLECULER_TRANSIT_STREAMS_RECEIVE_ACTIVE_DESC, MOLECULER_TRANSPORTER_PACKETS_RECEIVED_BYTES, MOLECULER_TRANSPORTER_PACKETS_RECEIVED_BYTES_DESC, MOLECULER_TRANSPORTER_PACKETS_RECEIVED_TOTAL, MOLECULER_TRANSPORTER_PACKETS_RECEIVED_TOTAL_DESC, MOLECULER_TRANSPORTER_PACKETS_SENT_BYTES, MOLECULER_TRANSPORTER_PACKETS_SENT_BYTES_DESC, MOLECULER_TRANSPORTER_PACKETS_SENT_TOTAL, MOLECULER_TRANSPORTER_PACKETS_SENT_TOTAL_DESC

Constructor Summary

Constructors
Constructor and Description
`ServiceBroker()` Creates a new ServiceBroker without `Transporter`.
`ServiceBroker(ServiceBrokerConfig config)` Creates a new ServiceBroker by the specified `configuration`.
`ServiceBroker(java.lang.String nodeID)` Creates a new ServiceBroker without `Transporter` and with the specified `ContextSource.nodeID`.
`ServiceBroker(java.lang.String nodeID, Cacher cacher, Transporter transporter)` Creates a new ServiceBroker with the specified `ContextSource.nodeID`, `Cacher`, and `Transporter`.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`broadcastServicesChanged()`
`static ServiceBrokerBuilder`	`builder()` Creates a new `ServiceBrokerBuilder` instance.
`ServiceBroker`	`createService(Service service)` Installs a new service instance and notifies other nodes about the actions/listeners of the new service.
`ServiceBroker`	`createService(java.lang.String name, Service service)` Installs a new service with the specified name (eg.
`Action`	`getAction(java.lang.String actionName)` Returns an action by name.
`Action`	`getAction(java.lang.String actionName, java.lang.String nodeID)` Returns an action by name and nodeID.
`ServiceBrokerConfig`	`getConfig()` Returns the configuration settings and internal components (event bus, cacher, service registry, etc.) of this node / broker.
`Service`	`getLocalService(java.lang.String serviceName)` Returns a local service by name (eg.
`org.slf4j.Logger`	`getLogger()` Returns the SLF4J logger of this broker instance.
`org.slf4j.Logger`	`getLogger(java.lang.Class<?> clazz)` Returns a logger named corresponding to the class passed as parameter.
`org.slf4j.Logger`	`getLogger(java.lang.String name)` Return a logger named according to the name parameter.
`java.lang.String`	`getNodeID()` Returns the unique `ContextSource.nodeID` of this node (~= ServiceBroker instance).
`java.lang.String`	`getProtocolVersion()` Returns the version of the implemented Moleculer Protocol.
`protected void`	`initJsonReader()` Set global JSON reader API (Jackson, Gson, Boon, FastJson, etc.).
`protected void`	`initJsonWriter()` Set global JSON writer API (Jackson, Gson, Boon, FastJson, etc.)
`io.datatree.Promise`	`ping(long timeoutMillis, java.lang.String nodeID)` Sends a PING message to the specified node.
`io.datatree.Promise`	`ping(java.lang.String nodeID)` Sends a PING message to the specified node.
`boolean`	`repl()` Starts a local (System in/out) developer console.
`boolean`	`repl(boolean local)` Starts a local (System in/out) or a remote (telnet-based) developer console.
`ServiceBroker`	`start()` Start broker.
`protected <TYPE extends MoleculerLifecycle> TYPE`	`start(TYPE component)` Starts the specified `MoleculerComponent`.
`ServiceBroker`	`stop()` Stop broker and all internal components (event bus, context factory, etc.).
`protected void`	`stop(MoleculerComponent component)` Stops the specified `MoleculerComponent`.
`ServiceBroker`	`use(java.util.Collection<Middleware> middlewares)` Installs a collection of middlewares.
`ServiceBroker`	`use(Middleware... middlewares)` Installs one or an array of middleware(s).
`io.datatree.Promise`	`waitForServices(long timeoutMillis, java.util.Collection<java.lang.String> services)` Waits for a collection of services.
`io.datatree.Promise`	`waitForServices(long timeoutMillis, java.lang.String... services)` Waits for one (or an array of) service(s).
`io.datatree.Promise`	`waitForServices(java.lang.String... services)` Waits for one or more services.

Methods inherited from class services.moleculer.context.ContextSource
broadcast, broadcast, broadcast, broadcast, broadcast, broadcast, broadcastLocal, broadcastLocal, broadcastLocal, call, call, call, call, call, call, createStream, emit, emit, emit, emit, emit, emit

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - SOFTWARE_VERSION
```
public static final java.lang.String SOFTWARE_VERSION
```
    Version of the Java ServiceBroker API.
    
    See Also:
    
    Constant Field Values
  - logger
```
protected static final org.slf4j.Logger logger
```
    SLF4J logger of this class.
  - config
```
protected final ServiceBrokerConfig config
```
    Configuration settings and internal components (event bus, cacher, service registry, etc.) of this node / broker. Use the getConfig method to access this object.
  - services
```
protected final java.util.concurrent.ConcurrentHashMap<java.lang.String,Service> services
```
    Services which defined and added to the Broker before the boot process.
  - serviceNames
```
protected final java.util.LinkedHashSet<java.lang.String> serviceNames
```
    Service names (keys).
  - middlewares
```
protected final java.util.LinkedHashSet<Middleware> middlewares
```
    Middlewares which defined and added to the Broker before the boot process.
  - strategyFactory
```
protected StrategyFactory strategyFactory
```
    Default (round-robin) service invocation factory. Use getConfig().getStrategyFactory() to access this instance.
  - serviceRegistry
```
protected ServiceRegistry serviceRegistry
```
    Implementation of the service registry of the current node. Use getConfig().getServiceRegistry() to access this instance.
    
    See Also:
    
    ContextSource.call(String, Object...)
  - transporter
```
protected Transporter transporter
```
    Implementation of the Transporter. Use getConfig().getTransporter() to access this instance. Can be null.
- Constructor Detail
  - ServiceBroker
```
public ServiceBroker(ServiceBrokerConfig config)
```
    Creates a new ServiceBroker by the specified configuration.
    
    Parameters:
    
    config - configuration of the Broker
  - ServiceBroker
```
public ServiceBroker()
```
    Creates a new ServiceBroker without Transporter. The ContextSource.nodeID is generated from the host name and process ID.
  - ServiceBroker
```
public ServiceBroker(java.lang.String nodeID)
```
    Creates a new ServiceBroker without Transporter and with the specified ContextSource.nodeID.
    
    Parameters:
    
    nodeID - the unique ContextSource.nodeID of this node
  - ServiceBroker
```
public ServiceBroker(java.lang.String nodeID,
                     Cacher cacher,
                     Transporter transporter)
```
    Creates a new ServiceBroker with the specified ContextSource.nodeID, Cacher, and Transporter.
    
    Parameters:
    
    nodeID - the unique ContextSource.nodeID of this node
    
    cacher - Cacher of this broker instance
    
    transporter - Transporter of this broker instance
- Method Detail
  - builder
```
public static ServiceBrokerBuilder builder()
```
    Creates a new ServiceBrokerBuilder instance. Sample of usage:
    
    ServiceBroker broker = ServiceBroker.builder().cacher(cacher).build();
    
    Returns:
    
    builder instance
  - getProtocolVersion
```
public java.lang.String getProtocolVersion()
```
    Returns the version of the implemented Moleculer Protocol. Can be configured with the "moleculer.protocol.version" System Property.
    
    Returns:
    
    version of the implemented protocol (eg. "4")
  - getConfig
```
public ServiceBrokerConfig getConfig()
```
    Returns the configuration settings and internal components (event bus, cacher, service registry, etc.) of this node / broker.
    
    Returns:
    
    configuration container
  - getNodeID
```
public java.lang.String getNodeID()
```
    Returns the unique ContextSource.nodeID of this node (~= ServiceBroker instance).
    
    Returns:
    
    unique ContextSource.nodeID
  - start
```
public ServiceBroker start()
                    throws java.lang.Exception
```
    Start broker. If has a Transporter, transporter.connect() will be called.
    
    Returns:
    
    this ServiceBroker instance (from "method chaining")
    
    Throws:
    
    java.lang.Exception - fatal error (missing classes or JARs, used port, etc.)
  - initJsonReader
```
protected void initJsonReader()
```
    Set global JSON reader API (Jackson, Gson, Boon, FastJson, etc.).
  - initJsonWriter
```
protected void initJsonWriter()
```
    Set global JSON writer API (Jackson, Gson, Boon, FastJson, etc.)
  - start
```
protected <TYPE extends MoleculerLifecycle> TYPE start(TYPE component)
                                                throws java.lang.Exception
```
    Starts the specified MoleculerComponent.
    
    Type Parameters:
    
    TYPE - Moleculer component (service registry, transporter, etc.)
    
    Parameters:
    
    component - component to start
    
    Returns:
    
    the started component
    
    Throws:
    
    java.lang.Exception - any configuration or I/O exceptions
  - stop
```
public ServiceBroker stop()
```
    Stop broker and all internal components (event bus, context factory, etc.). If the Broker has a Transporter, transporter.disconnect() will be called.
    
    Returns:
    
    this ServiceBroker instance (from "method chaining")
  - stop
```
protected void stop(MoleculerComponent component)
```
    Stops the specified MoleculerComponent.
    
    Parameters:
    
    component - component to stop
  - getLogger
```
public org.slf4j.Logger getLogger()
```
    Returns the SLF4J logger of this broker instance.
    
    Returns:
    
    logger instance
  - getLogger
```
public org.slf4j.Logger getLogger(java.lang.Class<?> clazz)
```
    Returns a logger named corresponding to the class passed as parameter.
    
    Parameters:
    
    clazz - the returned logger will be named after clazz
    
    Returns:
    
    logger instance
  - getLogger
```
public org.slf4j.Logger getLogger(java.lang.String name)
```
    Return a logger named according to the name parameter.
    
    Parameters:
    
    name - the name of the logger
    
    Returns:
    
    logger instance
  - createService
```
public ServiceBroker createService(Service service)
```
    Installs a new service instance and notifies other nodes about the actions/listeners of the new service.
    
    Parameters:
    
    service - the new service instance
    
    Returns:
    
    this ServiceBroker instance (from "method chaining")
  - createService
```
public ServiceBroker createService(java.lang.String name,
                                   Service service)
```
    Installs a new service with the specified name (eg. "user" service) and notifies other nodes about the actions/listeners of this new service.
    
    Parameters:
    
    name - custom service name (eg. "user", "logger", "configurator", etc.)
    
    service - the new service instance
    
    Returns:
    
    this ServiceBroker instance (from "method chaining")
  - broadcastServicesChanged
```
protected void broadcastServicesChanged()
```
  - getLocalService
```
public Service getLocalService(java.lang.String serviceName)
```
    Returns a local service by name (eg. "user" service).
    
    Parameters:
    
    serviceName - service name (eg. "user", "logger", "configurator", etc.)
    
    Returns:
    
    local service instance
    
    Throws:
    
    java.util.NoSuchElementException - if the service name is not valid
  - use
```
public ServiceBroker use(java.util.Collection<Middleware> middlewares)
```
    Installs a collection of middlewares.
    
    Parameters:
    
    middlewares - collection of middlewares
    
    Returns:
    
    this ServiceBroker instance (from "method chaining")
  - use
```
public ServiceBroker use(Middleware... middlewares)
```
    Installs one or an array of middleware(s).
    
    Parameters:
    
    middlewares - array of middlewares
    
    Returns:
    
    this ServiceBroker instance (from "method chaining")
  - getAction
```
public Action getAction(java.lang.String actionName)
```
    Returns an action by name.
    
    Parameters:
    
    actionName - name of the action (in "service.action" syntax, eg. "math.add")
    
    Returns:
    
    local or remote action container
  - getAction
```
public Action getAction(java.lang.String actionName,
                        java.lang.String nodeID)
```
    Returns an action by name and nodeID.
    
    Parameters:
    
    actionName - name of the action (in "service.action" syntax, eg. "math.add")
    
    nodeID - node identifier where the service is located
    
    Returns:
    
    local or remote action container
  - waitForServices
```
public io.datatree.Promise waitForServices(java.lang.String... services)
```
    Waits for one or more services. Sample code:
    
    broker.waitForServices("logger", "printer").then(in -> {
    broker.getLogger().info("Logger and printer started");
    }
    
    Parameters:
    
    services - service names
    
    Returns:
    
    a listenable Promise
  - waitForServices
```
public io.datatree.Promise waitForServices(long timeoutMillis,
                                           java.lang.String... services)
```
    Waits for one (or an array of) service(s). Sample code:
    
    broker.waitForServices(5000, "logger").then(in -> {
    broker.getLogger().info("Logger started successfully");
    }.catchError(error -> {
    broker.getLogger().info("Logger did not start");
    }
    
    Parameters:
    
    timeoutMillis - timeout in milliseconds
    
    services - array of service names
    
    Returns:
    
    listenable Promise
  - waitForServices
```
public io.datatree.Promise waitForServices(long timeoutMillis,
                                           java.util.Collection<java.lang.String> services)
```
    Waits for a collection of services. Sample code:
    
    Set<String> serviceNames = ...
    broker.waitForServices(5000, serviceNames).then(in -> {
    broker.getLogger().info("Ok");
    }.catchError(error -> {
    broker.getLogger().info("Failed / timeout");
    }
    
    Parameters:
    
    timeoutMillis - timeout in milliseconds
    
    services - collection of service names
    
    Returns:
    
    listenable Promise
  - ping
```
public io.datatree.Promise ping(java.lang.String nodeID)
```
    Sends a PING message to the specified node. The ping timeout is 3 seconds. Sample:
    
    broker.ping("node2").then(in -> {
    broker.getLogger().info("Ok");
    }.catchError(error -> {
    broker.getLogger().info("Ping timeouted");
    }
    
    Parameters:
    
    nodeID - node ID of the destination node
    
    Returns:
    
    listenable Promise
  - ping
```
public io.datatree.Promise ping(long timeoutMillis,
                                java.lang.String nodeID)
```
    Sends a PING message to the specified node. Sample:
    
    broker.ping(5000, "node2").then(in -> {
    broker.getLogger().info("Ok");
    }.catchError(error -> {
    broker.getLogger().info("Ping timeouted");
    }
    
    Parameters:
    
    timeoutMillis - ping timeout in milliseconds
    
    nodeID - node ID of the destination node
    
    Returns:
    
    listenable Promise
  - repl
```
public boolean repl()
```
    Starts a local (System in/out) developer console. You must install "moleculer-java-repl" dependency for use this feature.
    
    Returns:
    
    true if started
  - repl
```
public boolean repl(boolean local)
```
    Starts a local (System in/out) or a remote (telnet-based) developer console. You must install "moleculer-java-repl" dependency to use this feature.
    
    Parameters:
    
    local - true = local console, false = telnet-based console
    
    Returns:
    
    true if started

Class ServiceBroker

Field Summary

Fields inherited from class services.moleculer.context.ContextSource

Fields inherited from interface services.moleculer.metrics.MetricConstants

Constructor Summary

Method Summary

Methods inherited from class services.moleculer.context.ContextSource

Methods inherited from class java.lang.Object

Field Detail

SOFTWARE_VERSION

logger

config

services

serviceNames

middlewares

strategyFactory

serviceRegistry

transporter

Constructor Detail

ServiceBroker

ServiceBroker

ServiceBroker

ServiceBroker

Method Detail

builder

getProtocolVersion

getConfig

getNodeID

start

initJsonReader

initJsonWriter

start

stop

stop

getLogger

getLogger

getLogger

createService

createService

broadcastServicesChanged

getLocalService

use

use

getAction

getAction

waitForServices

waitForServices

waitForServices

ping

ping

repl

repl