ServerEnvironment (server 2.0.0-SNAPSHOT.0 API)

java.lang.Object
- io.spine.server.ServerEnvironment

All Implemented Interfaces:

java.lang.AutoCloseable
```
public final class ServerEnvironment
extends java.lang.Object
implements java.lang.AutoCloseable
```
The server conditions and configuration under which the application operates.
Configuration

Some parts of the ServerEnvironment can be customized based on the EnvironmentType. To do so, one of the overloads of the use method can be called. Two environment types exist out of the box: Tests and Production. For example:
```
     ServerEnvironment.when(Production.class)
                      .use(productionStorageFactory)
                      .use(memoizingTracerFactory);
     ServerEnvironment.when(Tests.class)
                      .use(testingStorageFactory);
 
```
A custom environment type may also be used:
```
     final class StagingEnvironment extends EnvironmentType {
         ...
     }

     ServerEnvironment.when(Staging.class)
                      .use(inMemoryStorageFactory);
 
```
If Staging is enabled, the specified value is going to be returned on ServerEnvironment.storageFactory().
Relation to Bounded Contexts

A ServerEnvironment instance is a singleton. It means that all Bounded Contexts which are deployed within the same JVM share the configuration of the server environment. Namely, under the same environment type, all Bounded Contexts will share the same storage factory, transport factory, delivery and tracing tools.
If one decides that some of the Bounded Contexts of an application requires custom settings, they should arrange a separate deployable artifact and distinct configuration of the respective ServerEnvironment for those Bounded Contexts. In this way, the Contexts would reside in their own JVMs and not overlap on interacting with this singleton.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static interface`	`ServerEnvironment.Fn<R>` A function which accepts a class of `EnvironmentType` and returns a value `configured` in a `ServerEnvironment`.
`static class`	`ServerEnvironment.TypeConfigurator` Allows to configure values used by the `ServerEnvironment` for the given type.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`close()` Releases resources associated with this instance.
`void`	`configureDeployment(java.util.function.Supplier<io.spine.server.DeploymentType> supplier)` Makes the `ServerEnvironment.deploymentType()` return the values from the provided supplier.
`Delivery`	`delivery()` Returns the delivery mechanism specific to this environment.
`io.spine.server.DeploymentType`	`deploymentType()` The type of the environment application is deployed to.
`static ServerEnvironment`	`instance()` Returns a singleton instance.
`CommandScheduler`	`newCommandScheduler()` Obtains command scheduling mechanism used by `CommandBus` in this environment.
`io.spine.server.NodeId`	`nodeId()` Obtains the identifier of the server node, on which this code is running at the moment.
`void`	`reset()` This is test-only method required for cleaning of the server environment instance in tests.
`void`	`scheduleCommandsUsing(java.util.function.Supplier<CommandScheduler> commandScheduler)` Assigns command scheduling mechanism used at this environment by all `CommandBus` instances.
`StorageFactory`	`storageFactory()` Obtains the storage factory for the current environment.
`java.util.Optional<TracerFactory>`	`tracing()` Obtains the `TracerFactory` associated with the current environment, if it was set.
`TransportFactory`	`transportFactory()` Obtains the transport factory for the current environment.
`java.lang.Class<? extends io.spine.base.EnvironmentType>`	`type()` Obtains the type of the current server environment.
`static ServerEnvironment.TypeConfigurator`	`when(java.lang.Class<? extends io.spine.base.EnvironmentType> type)` Starts flowing API chain for configuring `ServerEnvironment` for the passed type.

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

- Method Detail
  - instance
```
public static ServerEnvironment instance()
```
    Returns a singleton instance.
  - type
```
public java.lang.Class<? extends io.spine.base.EnvironmentType> type()
```
    Obtains the type of the current server environment.
    
    API Note:
    
    This is a convenience method for server-side configuration code, which simply delegates to Environment.type().
  - deploymentType
```
public io.spine.server.DeploymentType deploymentType()
```
    The type of the environment application is deployed to.
  - delivery
```
public Delivery delivery()
```
    Returns the delivery mechanism specific to this environment.
    Unless updated manually, returns a local implementation of Delivery.
  - newCommandScheduler
```
public CommandScheduler newCommandScheduler()
```
    Obtains command scheduling mechanism used by CommandBus in this environment.
  - scheduleCommandsUsing
```
public void scheduleCommandsUsing(java.util.function.Supplier<CommandScheduler> commandScheduler)
```
    Assigns command scheduling mechanism used at this environment by all CommandBus instances.
    If not configured, ExecutorCommandScheduler is used.
  - nodeId
```
public io.spine.server.NodeId nodeId()
```
    Obtains the identifier of the server node, on which this code is running at the moment.
    At the moment, the node identifier is always UUID-generated. In future versions of the framework it is expected to become configurable.
  - configureDeployment
```
public void configureDeployment(java.util.function.Supplier<io.spine.server.DeploymentType> supplier)
```
    Makes the ServerEnvironment.deploymentType() return the values from the provided supplier.
    When supplying your own deployment type in tests, remember to reset it during tear down.
  - tracing
```
public java.util.Optional<TracerFactory> tracing()
```
    Obtains the TracerFactory associated with the current environment, if it was set.
  - storageFactory
```
public StorageFactory storageFactory()
```
    Obtains the storage factory for the current environment.
    For tests, if the value was not set, defaults to a new InMemoryStorageFactory.
    For other environments, if the value was not set, throws a IllegalStateException.
    
    Returns:
    
    StorageFactory instance for the storage for the current environment
    
    Throws:
    
    java.lang.IllegalStateException - if the value StorageFactory was not configured prior to the call
  - transportFactory
```
public TransportFactory transportFactory()
```
    Obtains the transport factory for the current environment.
    In the testing environment, if the factory was not assigned, assigns a new InMemoryTransportFactory and returns it.
    For all other environment types, throws an IllegalStateException.
    If the factory is not assigned in the Tests mode, assigns the instance of InMemoryTransportFactory and returns it.
  - reset
```
public void reset()
```
    This is test-only method required for cleaning of the server environment instance in tests.
  - close
```
public void close()
           throws java.lang.Exception
```
    Releases resources associated with this instance.
    
    Specified by:
    
    close in interface java.lang.AutoCloseable
    
    Throws:
    
    java.lang.Exception
  - when
```
public static ServerEnvironment.TypeConfigurator when(java.lang.Class<? extends io.spine.base.EnvironmentType> type)
```
    Starts flowing API chain for configuring ServerEnvironment for the passed type.

Class ServerEnvironment

Configuration

Relation to Bounded Contexts

Nested Class Summary

Method Summary

Methods inherited from class java.lang.Object

Method Detail

instance

type

deploymentType

delivery

newCommandScheduler

scheduleCommandsUsing

nodeId

configureDeployment

tracing

storageFactory

transportFactory

reset

close

when