vertx-lang-scala-docs_2.12 3.4.1 API < Back
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# Packages

-  package root
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    root
-  package io
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    root
-  package vertx
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    io
-  package scala
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    vertx
-  package core
  Definition Classes
    scala
-  package cli
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    core
-  package datagram
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    core
-  package dns
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    core
-  package eventbus
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    core
-  package file
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-  package http
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    core
-  package metrics
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    core
-  package net
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    core
-  package parsetools
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    core
-  package shareddata
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    core
-  package streams
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    core
- CompositeFuture
- Context
- DeploymentOptions
- Future
- MultiMap
- TimeoutStream
- Vertx
- VertxOptions
- WorkerExecutor

c

io.vertx.scala.core

# Context 

###
Companion object Context

#### class Context extends AnyRef

The execution context of a scala-function execution.

When Vert.x provides an event to a handler or calls the start or stop methods of a io.vertx.lang.scala.ScalaVerticle, the execution is associated with a `Context`.

Usually a context is an *event-loop context* and is tied to a specific event loop thread. So executions for that context always occur on that exact same event loop thread.

In the case of worker verticles and running inline blocking code a worker context will be associated with the execution which will use a thread from the worker thread pool.

When a handler is set by a thread associated with a specific context, the Vert.x will guarantee that when that handler is executed, that execution will be associated with the same context.

If a handler is set by a thread not associated with a context (i.e. a non Vert.x thread). Then a new context will be created for that handler.

In other words, a context is propagated.

This means that when a verticle is deployed, any handlers it sets will be associated with the same context - the context of the verticle.

This means (in the case of a standard verticle) that the verticle code will always be executed with the exact same thread, so you don't have to worry about multi-threaded acccess to the verticle state and you can code your application as single threaded.

This class also allows arbitrary data to be io.vertx.scala.core.Context#put and io.vertx.scala.core.Context#get on the context so it can be shared easily amongst different handlers of, for example, a verticle instance.

This class also provides io.vertx.scala.core.Context#runOnContext which allows an action to be executed asynchronously using the same context.

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### Instance Constructors

1.  new Context(_asJava: AnyRef)

### Value Members

1.  final def !=(arg0: Any): Boolean
   Definition Classes
     AnyRef → Any
2.  final def ##(): Int
   Definition Classes
     AnyRef → Any
3.  final def ==(arg0: Any): Boolean
   Definition Classes
     AnyRef → Any
4.  final def asInstanceOf[T0]: T0
   Definition Classes
     Any
5.  def asJava: AnyRef
6.  def clone(): AnyRef
   Attributes
     protected[java.lang]
   Definition Classes
     AnyRef
   Annotations
     @throws( ... )
7.  def config(): Option[JsonObject]

   If the context is associated with a Verticle deployment, this returns the configuration that was specified when the verticle was deployed.

   If the context is associated with a Verticle deployment, this returns the configuration that was specified when the verticle was deployed.

   returns

     the configuration of the deployment or null if not a Verticle deployment

8.  def deploymentID(): String

   If the context is associated with a Verticle deployment, this returns the deployment ID of that deployment.

   If the context is associated with a Verticle deployment, this returns the deployment ID of that deployment.

   returns

     the deployment ID of the deployment or null if not a Verticle deployment

9.  final def eq(arg0: AnyRef): Boolean
   Definition Classes
     AnyRef
10.  def equals(arg0: Any): Boolean
    Definition Classes
      AnyRef → Any
11.  def exceptionHandler(handler: Handler[Throwable]): Context

    Set an exception handler called when the context runs an action throwing an uncaught throwable.

    Set an exception handler called when the context runs an action throwing an uncaught throwable.

    When this handler is called, io.vertx.scala.core.Vertx#currentContext will return this context.

    handler

      the exception handler

    returns

      a reference to this, so the API can be used fluently

12.  def executeBlocking[T](blockingFunction: () ⇒ T, ordered: Boolean = true): scala.concurrent.Future[T]

    Safely execute some blocking code.

    Safely execute some blocking code.

    Executes the blocking code in the handler `blockingCodeHandler` using a thread from the worker pool.

    When the code is complete the returned Future will be completed with the result.

    blockingFunction

      function containing blocking code

    ordered

      if true then if executeBlocking is called several times on the same context, the executions for that context will be executed serially, not in parallel. if false then they will be no ordering guarantees

    returns

      a Future representing the result of the blocking operation

13.  def finalize(): Unit
    Attributes
      protected[java.lang]
    Definition Classes
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    Annotations
      @throws( classOf[java.lang.Throwable] )
14.  def get[T](key: String)(implicit arg0: scala.reflect.api.JavaUniverse.TypeTag[T]): T

    Get some data from the context.

    Get some data from the context.

    key

      the key of the data

    returns

      the data

15.  final def getClass(): Class[_]
    Definition Classes
      AnyRef → Any
16.  def getInstanceCount(): Int

    returns

      the number of instances of the verticle that were deployed in the deployment (if any) related to this context

17.  def hashCode(): Int
    Definition Classes
      AnyRef → Any
18.  def isEventLoopContext(): Boolean

    Is the current context an event loop context?

    Is the current context an event loop context?

    NOTE! when running blocking code using io.vertx.scala.core.Vertx#executeBlockingFuture from a standard (not worker) verticle, the context will still an event loop context and this will return true.

    returns

      true if false otherwise

19.  final def isInstanceOf[T0]: Boolean
    Definition Classes
      Any
20.  def isMultiThreadedWorkerContext(): Boolean

    Is the current context a multi-threaded worker context?

    Is the current context a multi-threaded worker context?

    returns

      true if the current context is a multi-threaded worker context, false otherwise

21.  def isWorkerContext(): Boolean

    Is the current context a worker context?

    Is the current context a worker context?

    NOTE! when running blocking code using io.vertx.scala.core.Vertx#executeBlockingFuture from a standard (not worker) verticle, the context will still an event loop context and this will return false.

    returns

      true if the current context is a worker context, false otherwise

22.  final def ne(arg0: AnyRef): Boolean
    Definition Classes
      AnyRef
23.  final def notify(): Unit
    Definition Classes
      AnyRef
24.  final def notifyAll(): Unit
    Definition Classes
      AnyRef
25.  def owner(): Vertx

    returns

      The Vertx instance that created the context

26.  def processArgs(): Buffer[String]

    The process args

27.  def put(key: String, value: AnyRef): Unit

    Put some data in the context.

    Put some data in the context.

    This can be used to share data between different handlers that share a context

    key

      the key of the data

    value

      the data

28.  def remove(key: String): Boolean

    Remove some data from the context.

    Remove some data from the context.

    key

      the key to remove

    returns

      true if removed successfully, false otherwise

29.  def runOnContext(action: Handler[Unit]): Unit

    Run the specified action asynchronously on the same context, some time after the current execution has completed.

    Run the specified action asynchronously on the same context, some time after the current execution has completed.

    action

      the action to run

30.  final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
      AnyRef
31.  def toString(): String
    Definition Classes
      AnyRef → Any
32.  final def wait(): Unit
    Definition Classes
      AnyRef
    Annotations
      @throws( ... )
33.  final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
      AnyRef
    Annotations
      @throws( ... )
34.  final def wait(arg0: Long): Unit
    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

### Inherited from AnyRef

### Inherited from Any

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