io.vertx.ext.auth

Interface VertxContextPRNG

All Known Implementing Classes:

PRNG

public interface VertxContextPRNG

A secure non blocking random number generator isolated to the current context. The PRNG is bound to the vert.x context and setup to close when the context shuts down.

When applicable, use of VertxContextPRNG rather than create new PRNG objects is helpful to keep the system entropy usage to the minimum avoiding potential blocking across the application.

The use of VertxContextPRNG is particularly appropriate when multiple handlers use random numbers.

Author:

Paulo Lopes

Method Summary

Modifier and Type	Method and Description
static VertxContextPRNG	current() Get or create a secure non blocking random number generator using the current vert.x context.
static VertxContextPRNG	current(Context context) Get or create a secure non blocking random number generator using the provided vert.x context.
static VertxContextPRNG	current(Vertx vertx) Get or create a secure non blocking random number generator using the current vert.x instance.
void	nextBytes(byte[] bytes) Fills the given byte array with random bytes.
int	nextInt() Returns a secure random int
int	nextInt(int bound) Returns a secure random int, between 0 (inclusive) and the specified bound (exclusive).
default String	nextString(int length) Returns a Base64 mime encoded String of random data with the given length.

Method Detail

current

static VertxContextPRNG current()

Get or create a secure non blocking random number generator using the current vert.x context. If there is no current context (i.e.: not running on the eventloop) then a IllegalStateException is thrown.

Returns:

A secure non blocking random number generator.

Throws:

IllegalStateException - when there is no context available.

current

static VertxContextPRNG current(Context context)

Get or create a secure non blocking random number generator using the provided vert.x context. This method will not throw an exception.

Parameters:

context - a Vert.x context.

Returns:

A secure non blocking random number generator.

current

static VertxContextPRNG current(Vertx vertx)

Get or create a secure non blocking random number generator using the current vert.x instance. Since the context might be different this method will attempt to use the current context first if available and then fall back to create a new instance of the PRNG.

Parameters:

vertx - a Vert.x instance.

Returns:

A secure non blocking random number generator.

nextBytes

void nextBytes(byte[] bytes)

Fills the given byte array with random bytes.

Parameters:

bytes - a byte array.

nextString

default String nextString(int length)

Returns a Base64 mime encoded String of random data with the given length. The length parameter refers to the length of the String before the encoding step.

Parameters:

length - the desired string length before Base64 encoding.

Returns:

A base 64 encoded string.

nextInt

int nextInt()

Returns a secure random int

Returns:

random int.

nextInt

int nextInt(int bound)

Returns a secure random int, between 0 (inclusive) and the specified bound (exclusive).

Parameters:

bound - the upper bound (exclusive), which must be positive.

Returns:

random int.