ResponseCache
public
abstract
class
ResponseCache
extends Object
 Known Direct Subclasses
| HttpResponseCache |
Caches HTTP and HTTPS responses to the filesystem so they may be reused,
saving time and bandwidth.
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Represents implementations of URLConnection caches. An instance of
such a class can be registered with the system by doing
ResponseCache.setDefault(ResponseCache), and the system will call
this object in order to:
- store resource data which has been retrieved from an
external source into the cache
- try to fetch a requested resource that may have been
stored in the cache
The ResponseCache implementation decides which resources
should be cached, and for how long they should be cached. If a
request resource cannot be retrieved from the cache, then the
protocol handlers will fetch the resource from its original
location.
The settings for URLConnection#useCaches controls whether the
protocol is allowed to use a cached response.
For more information on HTTP caching, see
RFC 2616: Hypertext
Transfer Protocol -- HTTP/1.1
Summary
Inherited methods |
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From
class
java.lang.Object
Object
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clone()
Creates and returns a copy of this object.
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boolean
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equals(Object obj)
Indicates whether some other object is "equal to" this one.
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void
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finalize()
Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.
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final
Class<?>
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getClass()
Returns the runtime class of this Object.
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int
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hashCode()
Returns a hash code value for the object.
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final
void
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notify()
Wakes up a single thread that is waiting on this object's
monitor.
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final
void
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notifyAll()
Wakes up all threads that are waiting on this object's monitor.
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String
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toString()
Returns a string representation of the object.
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final
void
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wait(long millis, int nanos)
Causes the current thread to wait until another thread invokes the
notify() method or the
notifyAll() method for this object, or
some other thread interrupts the current thread, or a certain
amount of real time has elapsed.
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final
void
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wait(long millis)
Causes the current thread to wait until either another thread invokes the
notify() method or the
notifyAll() method for this object, or a
specified amount of time has elapsed.
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final
void
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wait()
Causes the current thread to wait until another thread invokes the
notify() method or the
notifyAll() method for this object.
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Public constructors
ResponseCache
ResponseCache ()
Public methods
get
CacheResponse get (URI uri,
String rqstMethod,
Map<String, List<String>> rqstHeaders)
Retrieve the cached response based on the requesting uri,
request method and request headers. Typically this method is
called by the protocol handler before it sends out the request
to get the network resource. If a cached response is returned,
that resource is used instead.
| Parameters |
|---|
uri |
URI:
a URI used to reference the requested
network resource |
rqstMethod |
String:
a String representing the request
method |
rqstHeaders |
Map:
- a Map from request header
field names to lists of field values representing
the current request headers |
| Returns |
|---|
CacheResponse |
a CacheResponse instance if available
from cache, or null otherwise |
getDefault
ResponseCache getDefault ()
Gets the system-wide response cache.
put
CacheRequest put (URI uri,
URLConnection conn)
The protocol handler calls this method after a resource has
been retrieved, and the ResponseCache must decide whether or
not to store the resource in its cache. If the resource is to
be cached, then put() must return a CacheRequest object which
contains an OutputStream that the protocol handler will
use to write the resource into the cache. If the resource is
not to be cached, then put must return null.
| Parameters |
|---|
uri |
URI:
a URI used to reference the requested
network resource |
conn |
URLConnection:
- a URLConnection instance that is used to fetch
the response to be cached |
| Returns |
|---|
CacheRequest |
a CacheRequest for recording the
response to be cached. Null return indicates that
the caller does not intend to cache the response. |
setDefault
void setDefault (ResponseCache responseCache)
Sets (or unsets) the system-wide cache.
Note: non-standard procotol handlers may ignore this setting.
| Parameters |
|---|
responseCache |
ResponseCache:
The response cache, or
null to unset the cache. |
Developers