com.amazonaws.auth

Class AWSCredentialsProviderChain

java.lang.Object

com.amazonaws.auth.AWSCredentialsProviderChain

All Implemented Interfaces:

AWSCredentialsProvider

Direct Known Subclasses:

DefaultAWSCredentialsProviderChain

public class AWSCredentialsProviderChain
extends Object
implements AWSCredentialsProvider

AWSCredentialsProvider implementation that chains together multiple credentials providers. When a caller first requests credentials from this provider, it calls all the providers in the chain, in the original order specified, until one can provide credentials, and then returns those credentials. If all of the credential providers in the chain have been called, and none of them can provide credentials, then this class will throw an exception indicated that no credentials are available.

By default, this class will remember the first credentials provider in the chain that was able to provide credentials, and will continue to use that provider when credentials are requested in the future, instead of traversing the chain each time. This behavior can be controlled through the setReuseLastProvider(boolean) method.

Constructor Summary

Constructors

Constructor and Description
AWSCredentialsProviderChain(AWSCredentialsProvider... credentialsProviders) Constructs a new AWSCredentialsProviderChain with the specified credential providers.

Method Summary

Methods

Modifier and Type	Method and Description
AWSCredentials	getCredentials() Returns AWSCredentials which the caller can use to authorize an AWS request.
boolean	getReuseLastProvider() Returns true if this chain will reuse the last successful credentials provider for future credentials requests, otherwise, false if it will search through the chain each time.
void	refresh() Forces this credentials provider to refresh its credentials.
void	setReuseLastProvider(boolean b) Enables or disables caching of the last successful credentials provider in this chain.

Methods inherited from class java.lang.Object

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

Constructor Detail

AWSCredentialsProviderChain

public AWSCredentialsProviderChain(AWSCredentialsProvider... credentialsProviders)

Constructs a new AWSCredentialsProviderChain with the specified credential providers. When credentials are requested from this provider, it will call each of these credential providers in the same order specified here until one of them returns AWS security credentials.

Parameters:

credentialsProviders - The chain of credentials providers.

Method Detail

getReuseLastProvider

public boolean getReuseLastProvider()

Returns true if this chain will reuse the last successful credentials provider for future credentials requests, otherwise, false if it will search through the chain each time.

Returns:

True if this chain will reuse the last successful credentials provider for future credentials requests.

setReuseLastProvider

public void setReuseLastProvider(boolean b)

Enables or disables caching of the last successful credentials provider in this chain. Reusing the last successful credentials provider will typically return credentials faster than searching through the chain.

Parameters:

b - Whether to enable or disable reusing the last successful credentials provider for future credentials requests instead of searching through the whole chain.

getCredentials

public AWSCredentials getCredentials()

Description copied from interface: AWSCredentialsProvider

Returns AWSCredentials which the caller can use to authorize an AWS request. Each implementation of AWSCredentialsProvider can chose its own strategy for loading credentials. For example, an implementation might load credentials from an existing key management system, or load new credentials when credentials are rotated.

Specified by:

getCredentials in interface AWSCredentialsProvider

Returns:

AWSCredentials which the caller can use to authorize an AWS request.

refresh

public void refresh()

Description copied from interface: AWSCredentialsProvider

Forces this credentials provider to refresh its credentials. For many implementations of credentials provider, this method may simply be a no-op, such as any credentials provider implementation that vends static/non-changing credentials. For other implementations that vend different credentials through out their lifetime, this method should force the credentials provider to refresh its credentials.

Specified by:

refresh in interface AWSCredentialsProvider