Package io.github.pr0methean.betterrandom.seed

Class RandomDotOrgAnonymousClient

java.lang.Object

io.github.pr0methean.betterrandom.seed.WebSeedClient

io.github.pr0methean.betterrandom.seed.RandomDotOrgAnonymousClient

All Implemented Interfaces:

SeedGenerator, Serializable

public class RandomDotOrgAnonymousClient
extends WebSeedClient

Connects to random.org's old API (via HTTPS) and downloads a set of random bits to use as seed data. It is generally better to use the DevRandomSeedGenerator where possible, as it should be much quicker. This seed generator is most useful on Microsoft Windows without Cygwin, and other platforms that do not provide /dev/random (or where that device is very slow).

Random.org collects randomness from atmospheric noise using 9 radios, located at undisclosed addresses in Dublin and Copenhagen and tuned to undisclosed AM/FM frequencies. (The secrecy is intended to help prevent tampering with the output using a well-placed radio transmitter, and the use of AM/FM helps ensure that any such tampering would cause illegal interference with broadcasts and quickly attract regulatory attention.)

Random.org has two APIs: an old API and a newer JSON-RPC API. Since the new one requires a key provided to each user by random.org, a client for the old one is still useful for anonymous access. However, if you have a key, you can instead use RandomDotOrgApi2Client.

Note that when using the old API, random.org limits the supply of free random numbers to any one IP address; if you operate from a fixed address (at least if you use IPv4), you can check your quota and buy more. On the new API, the quota is per key rather than per IP, and commercial-use pricing follows a different scheme.

Author:

Daniel Dyer (original version), Chris Hennick (refactoring)

See Also:

Serialized Form

Field Summary

Fields inherited from class io.github.pr0methean.betterrandom.seed.WebSeedClient

CLOCK, earliestNextAttempt, JSON_PARSER, lock, userAgent

Fields inherited from interface io.github.pr0methean.betterrandom.seed.SeedGenerator

EMPTY_SEED

Constructor Summary

Constructors

Constructor	Description
RandomDotOrgAnonymousClient()
RandomDotOrgAnonymousClient(WebSeedClientConfiguration configuration)

Method Summary

Modifier and Type	Method	Description
protected void	downloadBytes(HttpURLConnection connection, byte[] seed, int offset, int length)	Performs a single request for random bytes.
protected URL	getConnectionUrl(int numBytes)
protected int	getMaxRequestSize()	Returns the maximum number of bytes that can be obtained with one request to the service.

Methods inherited from class io.github.pr0methean.betterrandom.seed.WebSeedClient

checkedGetObject, divideRoundingUp, equals, generateSeed, getProxy, getResponseReader, getRetryDelayMs, getSocketFactory, hashCode, isWorthTrying, modRange1ToM, openConnection, parseJsonResponse

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.github.pr0methean.betterrandom.seed.SeedGenerator

generateSeed

Constructor Detail

RandomDotOrgAnonymousClient

public RandomDotOrgAnonymousClient(WebSeedClientConfiguration configuration)

RandomDotOrgAnonymousClient

public RandomDotOrgAnonymousClient()

Method Detail

getMaxRequestSize

protected int getMaxRequestSize()

Description copied from class: WebSeedClient

Returns the maximum number of bytes that can be obtained with one request to the service. When a seed larger than this is needed, it is obtained using multiple requests.

Specified by:

getMaxRequestSize in class WebSeedClient

Returns:

the maximum number of bytes per request

getConnectionUrl

protected URL getConnectionUrl(int numBytes)

Specified by:

getConnectionUrl in class WebSeedClient

downloadBytes

protected void downloadBytes(HttpURLConnection connection,
                             byte[] seed,
                             int offset,
                             int length)
                      throws IOException

Description copied from class: WebSeedClient

Performs a single request for random bytes.

Specified by:

downloadBytes in class WebSeedClient

Parameters:

connection - the connection to download from

seed - the array to save them to

offset - the first index to save them to in the array

length - the number of bytes to download

Throws:

IOException - if a connection error occurs