public abstract class

Request

extends Object
implements Comparable<T>
java.lang.Object
   ↳ com.android.volley.Request<T>
Known Direct Subclasses
Known Indirect Subclasses

Class Overview

Base class for all network requests.

Summary

Nested Classes
interface Request.Method Supported request methods. 
enum Request.Priority Priority values. 
Public Constructors
Request(String url, Response.ErrorListener listener)
This constructor is deprecated. Use Request(int, String, com.android.volley.Response.ErrorListener).
Request(int method, String url, Response.ErrorListener listener)
Creates a new request with the given method (one of the values from Request.Method), URL, and error listener.
Public Methods
void addMarker(String tag)
Adds an event to this request's event log; for debugging.
void cancel()
Mark this request as canceled.
int compareTo(Request<T> other)
Our comparator sorts from high to low priority, and secondarily by sequence number to provide FIFO ordering.
void deliverError(VolleyError error)
Delivers error message to the ErrorListener that the Request was initialized with.
byte[] getBody()
Returns the raw POST or PUT body to be sent.
String getBodyContentType()
Returns the content type of the POST or PUT body.
Cache.Entry getCacheEntry()
Returns the annotated cache entry, or null if there isn't one.
String getCacheKey()
Returns the cache key for this request.
Response.ErrorListener getErrorListener()
Map<String, String> getHeaders()
Returns a list of extra HTTP headers to go along with this request.
int getMethod()
Return the method for this request.
byte[] getPostBody()
This method is deprecated. Use getBody() instead.
String getPostBodyContentType()
This method is deprecated. Use getBodyContentType() instead.
Request.Priority getPriority()
Returns the Request.Priority of this request; NORMAL by default.
RetryPolicy getRetryPolicy()
Returns the retry policy that should be used for this request.
final int getSequence()
Returns the sequence number of this request.
Object getTag()
Returns this request's tag.
final int getTimeoutMs()
Returns the socket timeout in milliseconds per retry attempt.
int getTrafficStatsTag()
String getUrl()
Returns the URL of this request.
boolean hasHadResponseDelivered()
Returns true if this request has had a response delivered for it.
boolean isCanceled()
Returns true if this request has been canceled.
void markDelivered()
Mark this request as having a response delivered on it.
Request<?> setCacheEntry(Cache.Entry entry)
Annotates this request with an entry retrieved for it from cache.
Request<?> setRequestQueue(RequestQueue requestQueue)
Associates this request with the given queue.
Request<?> setRetryPolicy(RetryPolicy retryPolicy)
Sets the retry policy for this request.
final Request<?> setSequence(int sequence)
Sets the sequence number of this request.
final Request<?> setShouldCache(boolean shouldCache)
Set whether or not responses to this request should be cached.
Request<?> setTag(Object tag)
Set a tag on this request.
final boolean shouldCache()
Returns true if responses to this request should be cached.
String toString()
Protected Methods
abstract void deliverResponse(T response)
Subclasses must implement this to perform delivery of the parsed response to their listeners.
Map<String, String> getParams()
Returns a Map of parameters to be used for a POST or PUT request.
String getParamsEncoding()
Returns which encoding should be used when converting POST or PUT parameters returned by getParams() into a raw POST or PUT body.
Map<String, String> getPostParams()
This method is deprecated. Use getParams() instead.
String getPostParamsEncoding()
This method is deprecated. Use getParamsEncoding() instead.
VolleyError parseNetworkError(VolleyError volleyError)
Subclasses can override this method to parse 'networkError' and return a more specific error.
abstract Response<T> parseNetworkResponse(NetworkResponse response)
Subclasses must implement this to parse the raw network response and return an appropriate response type.
[Expand]
Inherited Methods
From class java.lang.Object
From interface java.lang.Comparable

Public Constructors

public Request (String url, Response.ErrorListener listener)

This constructor is deprecated.
Use Request(int, String, com.android.volley.Response.ErrorListener).

Creates a new request with the given URL and error listener. Note that the normal response listener is not provided here as delivery of responses is provided by subclasses, who have a better idea of how to deliver an already-parsed response.

public Request (int method, String url, Response.ErrorListener listener)

Creates a new request with the given method (one of the values from Request.Method), URL, and error listener. Note that the normal response listener is not provided here as delivery of responses is provided by subclasses, who have a better idea of how to deliver an already-parsed response.

Public Methods

public void addMarker (String tag)

Adds an event to this request's event log; for debugging.

public void cancel ()

Mark this request as canceled. No callback will be delivered.

public int compareTo (Request<T> other)

Our comparator sorts from high to low priority, and secondarily by sequence number to provide FIFO ordering.

public void deliverError (VolleyError error)

Delivers error message to the ErrorListener that the Request was initialized with.

Parameters
error Error details

public byte[] getBody ()

Returns the raw POST or PUT body to be sent.

By default, the body consists of the request parameters in application/x-www-form-urlencoded format. When overriding this method, consider overriding getBodyContentType() as well to match the new body format.

Throws
AuthFailureError in the event of auth failure

public String getBodyContentType ()

Returns the content type of the POST or PUT body.

public Cache.Entry getCacheEntry ()

Returns the annotated cache entry, or null if there isn't one.

public String getCacheKey ()

Returns the cache key for this request. By default, this is the URL.

public Response.ErrorListener getErrorListener ()

Returns

public Map<String, String> getHeaders ()

Returns a list of extra HTTP headers to go along with this request. Can throw AuthFailureError as authentication may be required to provide these values.

Throws
AuthFailureError In the event of auth failure

public int getMethod ()

Return the method for this request. Can be one of the values in Request.Method.

public byte[] getPostBody ()

This method is deprecated.
Use getBody() instead.

Returns the raw POST body to be sent.

Throws
AuthFailureError In the event of auth failure

public String getPostBodyContentType ()

This method is deprecated.
Use getBodyContentType() instead.

public Request.Priority getPriority ()

Returns the Request.Priority of this request; NORMAL by default.

public RetryPolicy getRetryPolicy ()

Returns the retry policy that should be used for this request.

public final int getSequence ()

Returns the sequence number of this request.

public Object getTag ()

Returns this request's tag.

See Also

public final int getTimeoutMs ()

Returns the socket timeout in milliseconds per retry attempt. (This value can be changed per retry attempt if a backoff is specified via backoffTimeout()). If there are no retry attempts remaining, this will cause delivery of a TimeoutError error.

public int getTrafficStatsTag ()

Returns

public String getUrl ()

Returns the URL of this request.

public boolean hasHadResponseDelivered ()

Returns true if this request has had a response delivered for it.

public boolean isCanceled ()

Returns true if this request has been canceled.

public void markDelivered ()

Mark this request as having a response delivered on it. This can be used later in the request's lifetime for suppressing identical responses.

public Request<?> setCacheEntry (Cache.Entry entry)

Annotates this request with an entry retrieved for it from cache. Used for cache coherency support.

Returns
  • This Request object to allow for chaining.

public Request<?> setRequestQueue (RequestQueue requestQueue)

Associates this request with the given queue. The request queue will be notified when this request has finished.

Returns
  • This Request object to allow for chaining.

public Request<?> setRetryPolicy (RetryPolicy retryPolicy)

Sets the retry policy for this request.

Returns
  • This Request object to allow for chaining.

public final Request<?> setSequence (int sequence)

Sets the sequence number of this request. Used by RequestQueue.

Returns
  • This Request object to allow for chaining.

public final Request<?> setShouldCache (boolean shouldCache)

Set whether or not responses to this request should be cached.

Returns
  • This Request object to allow for chaining.

public Request<?> setTag (Object tag)

Set a tag on this request. Can be used to cancel all requests with this tag by cancelAll(Object).

Returns
  • This Request object to allow for chaining.

public final boolean shouldCache ()

Returns true if responses to this request should be cached.

public String toString ()

Protected Methods

protected abstract void deliverResponse (T response)

Subclasses must implement this to perform delivery of the parsed response to their listeners. The given response is guaranteed to be non-null; responses that fail to parse are not delivered.

Parameters
response The parsed response returned by parseNetworkResponse(NetworkResponse)

protected Map<String, String> getParams ()

Returns a Map of parameters to be used for a POST or PUT request. Can throw AuthFailureError as authentication may be required to provide these values.

Note that you can directly override getBody() for custom data.

Throws
AuthFailureError in the event of auth failure

protected String getParamsEncoding ()

Returns which encoding should be used when converting POST or PUT parameters returned by getParams() into a raw POST or PUT body.

This controls both encodings:

  1. The string encoding used when converting parameter names and values into bytes prior to URL encoding them.
  2. The string encoding used when converting the URL encoded parameters into a raw byte array.

protected Map<String, String> getPostParams ()

This method is deprecated.
Use getParams() instead.

Returns a Map of POST parameters to be used for this request, or null if a simple GET should be used. Can throw AuthFailureError as authentication may be required to provide these values.

Note that only one of getPostParams() and getPostBody() can return a non-null value.

Throws
AuthFailureError In the event of auth failure

protected String getPostParamsEncoding ()

This method is deprecated.
Use getParamsEncoding() instead.

Returns which encoding should be used when converting POST parameters returned by getPostParams() into a raw POST body.

This controls both encodings:

  1. The string encoding used when converting parameter names and values into bytes prior to URL encoding them.
  2. The string encoding used when converting the URL encoded parameters into a raw byte array.

protected VolleyError parseNetworkError (VolleyError volleyError)

Subclasses can override this method to parse 'networkError' and return a more specific error.

The default implementation just returns the passed 'networkError'.

Parameters
volleyError the error retrieved from the network
Returns
  • an NetworkError augmented with additional information

protected abstract Response<T> parseNetworkResponse (NetworkResponse response)

Subclasses must implement this to parse the raw network response and return an appropriate response type. This method will be called from a worker thread. The response will not be delivered if you return null.

Parameters
response Response from the network
Returns
  • The parsed response, or null in the case of an error