Package com.google.appengine.api.urlfetch

Interface URLFetchService

public interface URLFetchService

The URLFetchService provides a way for user code to execute HTTP requests to external URLs.

Chunked and hanging requests are not supported, and all content will be returned in a single block.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	DEFAULT_DEADLINE_PROPERTY	System property for defining a global default URLFetch deadline.
static final String	DEFAULT_TLS_VALIDATION_PROPERTY	System property to turn on server certificate validation by default.

Method Summary

Modifier and Type	Method	Description
HTTPResponse	fetch(HTTPRequest request)	Execute the specified request and return its response.
HTTPResponse	fetch(URL url)	Convenience method for retrieving a specific URL via a HTTP GET request with no custom headers and default values for all FetchOptions attributes.
Future<HTTPResponse>	fetchAsync(HTTPRequest request)	Asynchronously execute the specified request and return its response.
Future<HTTPResponse>	fetchAsync(URL url)	Convenience method for asynchronously retrieving a specific URL via a HTTP GET request with no custom headers and default values for all FetchOptions attributes.

Field Details

DEFAULT_DEADLINE_PROPERTY

static final String DEFAULT_DEADLINE_PROPERTY

System property for defining a global default URLFetch deadline.

See Also:

• Constant Field Values

DEFAULT_TLS_VALIDATION_PROPERTY

static final String DEFAULT_TLS_VALIDATION_PROPERTY

System property to turn on server certificate validation by default. The value of the property should be the string "true" in order to enable validation.

See Also:

• Constant Field Values

Method Details

fetch

HTTPResponse fetch(URL url)
            throws IOException

Convenience method for retrieving a specific URL via a HTTP GET request with no custom headers and default values for all FetchOptions attributes. For more complex requests, use fetch(HTTPRequest).

Parameters:

url - The url to fetch.

Returns:

The result of the fetch.

Throws:

MalformedURLException - If the provided URL is malformed.

RequestPayloadTooLargeException - If the provided payload exceeds the limit.

IOException - If the remote service could not be contacted or the URL could not be fetched.

SocketTimeoutException - If the request takes too long to respond.

ResponseTooLargeException - If the response is too large.

SSLHandshakeException - If the server's SSL certificate could not be validated and validation was requested.

fetch

HTTPResponse fetch(HTTPRequest request)
            throws IOException

Execute the specified request and return its response.

Parameters:

request - The http request.

Returns:

The result of the fetch.

Throws:

IllegalArgumentException - If request.getMethod is not supported by the URLFetchService.

MalformedURLException - If the provided URL is malformed.

RequestPayloadTooLargeException - If the provided payload exceeds the limit.

IOException - If the remote service could not be contacted or the URL could not be fetched.

SocketTimeoutException - If the request takes too long to respond.

ResponseTooLargeException - If response truncation has been disabled via the FetchOptions object on request and the response is too large. Some responses are too large to even retrieve from the remote server, and in these cases the exception is thrown even if response truncation is enabled.

SSLHandshakeException - If the server's SSL certificate could not be validated and validation was requested.

fetchAsync

Future<HTTPResponse> fetchAsync(URL url)

Convenience method for asynchronously retrieving a specific URL via a HTTP GET request with no custom headers and default values for all FetchOptions attributes. For more complex requests, use fetchAsync(HTTPRequest).

Parameters:

url - The url to fetch.

Returns:

A future containing the result of the fetch, or one of the exceptions documented for fetch(URL).

fetchAsync

Future<HTTPResponse> fetchAsync(HTTPRequest request)

Asynchronously execute the specified request and return its response.

Parameters:

request - The http request.

Returns:

A future containing the result of the fetch, or one of the exceptions documented for fetch(HTTPRequest).