InjectionContext (Guice Context Scopes 8.2 API)

java.lang.Object
- pl.morgwai.base.guice.scopes.InjectionContext

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

TrackableContext
```
public abstract class InjectionContext
extends Object
implements Serializable
```
Stores objects scoped to the context of some processing/call/request/session, such as an RPC, a servlet request processing, a session combining several calls etc. Stored objects can be obtained via Guice injections configured with bindings scoped in the associated ContextScope.
Note: most context classes should rather extend TrackableContext subclass instead of this one. The main exception are context types that are induced by other contexts: see InducedContextScope.

Subclasses usually add properties and methods specific to their type, like their call's arguments, a reference to their session object etc.

Multiple threads may run within the same context, but the scoped objects that they access must be thread-safe or properly synchronized.

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor Description

InjectionContext()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected <T> T`	`provideIfAbsent(Key<T> key, Provider<T> provider)`	Obtains the object given by `key`.
`void`	`removeScopedObject(Key<?> key)`	Removes the object given by `key` from this context.

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

- Constructor Detail
  - InjectionContext
```
public InjectionContext()
```
- Method Detail
  - removeScopedObject
```
public void removeScopedObject(Key<?> key)
```
    Removes the object given by key from this context. This is sometimes useful to force the associated ContextScope to obtain a new instance from the unscoped provider if the current one is not usable anymore (for example a timed-out connection, etc).
    Note: If multiple threads run within the same context, care must be taken to prevent some of them from retaining the old stale instances.
  - provideIfAbsent
```
protected <T> T provideIfAbsent(Key<T> key,
                                Provider<T> provider)
```
    Obtains the object given by key. If there is a stored instance in this context, it is returned immediately. Otherwise, a new instance is obtained from provider and stored for subsequent calls.