# ResponseCache
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
Summary:[Ctors](https://developer.android.com/reference/java/net/ResponseCache#pubctors)\|[Methods](https://developer.android.com/reference/java/net/ResponseCache#pubmethods)\|[Inherited Methods](https://developer.android.com/reference/java/net/ResponseCache#inhmethods)
# ResponseCache
`
public
abstract
class
ResponseCache
`
`
extends `[Object](https://developer.android.com/reference/java/lang/Object)`
``
`
|---|------------------------|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) ||
| ↳ | java.net.ResponseCache |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Known direct subclasses [HttpResponseCache](https://developer.android.com/reference/android/net/http/HttpResponseCache) |-------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------| | [HttpResponseCache](https://developer.android.com/reference/android/net/http/HttpResponseCache) | Caches HTTP and HTTPS responses to the filesystem so they may be reused, saving time and bandwidth. | |
*** ** * ** ***
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*](http://www.ietf.org/rfc/rfc2616.txt)
## Summary
| ### Public constructors ||
|---------------------------------------------------------------------------------------------------------|---|
| ` `[ResponseCache](https://developer.android.com/reference/java/net/ResponseCache#ResponseCache())`() ` |
| ### Public methods ||
|---------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ` abstract `[CacheResponse](https://developer.android.com/reference/java/net/CacheResponse) | ` `[get](https://developer.android.com/reference/java/net/ResponseCache#get(java.net.URI,%20java.lang.String,%20java.util.Map>))`(`[URI](https://developer.android.com/reference/java/net/URI)` uri, `[String](https://developer.android.com/reference/java/lang/String)` rqstMethod, `[Map](https://developer.android.com/reference/java/util/Map)`<`[String](https://developer.android.com/reference/java/lang/String)`, `[List](https://developer.android.com/reference/java/util/List)`<`[String](https://developer.android.com/reference/java/lang/String)`>> rqstHeaders) ` Retrieve the cached response based on the requesting uri, request method and request headers. |
| ` static `[ResponseCache](https://developer.android.com/reference/java/net/ResponseCache) | ` `[getDefault](https://developer.android.com/reference/java/net/ResponseCache#getDefault())`() ` Gets the system-wide response cache. |
| ` abstract `[CacheRequest](https://developer.android.com/reference/java/net/CacheRequest) | ` `[put](https://developer.android.com/reference/java/net/ResponseCache#put(java.net.URI,%20java.net.URLConnection))`(`[URI](https://developer.android.com/reference/java/net/URI)` uri, `[URLConnection](https://developer.android.com/reference/java/net/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. |
| ` static void` | ` `[setDefault](https://developer.android.com/reference/java/net/ResponseCache#setDefault(java.net.ResponseCache))`(`[ResponseCache](https://developer.android.com/reference/java/net/ResponseCache)` responseCache) ` Sets (or unsets) the system-wide cache. |
| ### Inherited methods |
|-----------------------|---|
| From class` `[java.lang.Object](https://developer.android.com/reference/java/lang/Object)` ` |--------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` `[Object](https://developer.android.com/reference/java/lang/Object) | ` `[clone](https://developer.android.com/reference/java/lang/Object#clone())`() ` Creates and returns a copy of this object. | | ` boolean` | ` `[equals](https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object))`(`[Object](https://developer.android.com/reference/java/lang/Object)` obj) ` Indicates whether some other object is "equal to" this one. | | ` void` | ` `[finalize](https://developer.android.com/reference/java/lang/Object#finalize())`() ` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. | | ` final `[Class](https://developer.android.com/reference/java/lang/Class)`` | ` `[getClass](https://developer.android.com/reference/java/lang/Object#getClass())`() ` Returns the runtime class of this`Object`. | | ` int` | ` `[hashCode](https://developer.android.com/reference/java/lang/Object#hashCode())`() ` Returns a hash code value for the object. | | ` final void` | ` `[notify](https://developer.android.com/reference/java/lang/Object#notify())`() ` Wakes up a single thread that is waiting on this object's monitor. | | ` final void` | ` `[notifyAll](https://developer.android.com/reference/java/lang/Object#notifyAll())`() ` Wakes up all threads that are waiting on this object's monitor. | | ` `[String](https://developer.android.com/reference/java/lang/String) | ` `[toString](https://developer.android.com/reference/java/lang/Object#toString())`() ` Returns a string representation of the object. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long,%20int))`(long timeoutMillis, int nanos) ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long))`(long timeoutMillis) ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait())`() ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*. | ||
## Public constructors
### ResponseCache
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public ResponseCache ()
```
## Public methods
### get
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public abstract CacheResponse get (URI uri,
String rqstMethod,
Map> 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](https://developer.android.com/reference/java/net/CacheResponse) | a`CacheResponse`instance if available from cache, or null otherwise
|
| Throws ||
|--------------------------------------------------------------------------------------------------------|-------------------------------------|
| [IOException](https://developer.android.com/reference/java/io/IOException) | if an I/O error occurs |
| [IllegalArgumentException](https://developer.android.com/reference/java/lang/IllegalArgumentException) | if any one of the arguments is null |
**See also:**
- [URLConnection.setUseCaches(boolean)](https://developer.android.com/reference/java/net/URLConnection#setUseCaches(boolean))
- [URLConnection.getUseCaches()](https://developer.android.com/reference/java/net/URLConnection#getUseCaches())
- [URLConnection.setDefaultUseCaches(boolean)](https://developer.android.com/reference/java/net/URLConnection#setDefaultUseCaches(boolean))
- [URLConnection.getDefaultUseCaches()](https://developer.android.com/reference/java/net/URLConnection#getDefaultUseCaches())
### getDefault
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public static ResponseCache getDefault ()
```
Gets the system-wide response cache.
| Returns ||
|---------------------------------------------------------------------------------|---------------------------------------|
| [ResponseCache](https://developer.android.com/reference/java/net/ResponseCache) | the system-wide`ResponseCache`
|
| Throws ||
|------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [SecurityException](https://developer.android.com/reference/java/lang/SecurityException) | If a security manager has been installed and it denies[NetPermission](https://developer.android.com/reference/java/net/NetPermission)`("getResponseCache")` |
**See also:**
- [setDefault(ResponseCache)](https://developer.android.com/reference/java/net/ResponseCache#setDefault(java.net.ResponseCache))
### put
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public abstract 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](https://developer.android.com/reference/java/net/CacheRequest) | a`CacheRequest`for recording the response to be cached. Null return indicates that the caller does not intend to cache the response.
|
| Throws ||
|--------------------------------------------------------------------------------------------------------|-------------------------------------|
| [IOException](https://developer.android.com/reference/java/io/IOException) | if an I/O error occurs |
| [IllegalArgumentException](https://developer.android.com/reference/java/lang/IllegalArgumentException) | if any one of the arguments is null |
### setDefault
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public static 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.
|
| Throws ||
|------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [SecurityException](https://developer.android.com/reference/java/lang/SecurityException) | If a security manager has been installed and it denies[NetPermission](https://developer.android.com/reference/java/net/NetPermission)`("setResponseCache")` |
**See also:**
- [getDefault()](https://developer.android.com/reference/java/net/ResponseCache#getDefault())