KeyStore.Builder

AI-generated Key Takeaways

• KeyStore.Builder provides a way to instantiate and initialize KeyStore objects, separating configuration from creation.

• It allows delaying password prompts until needed and provides methods to retrieve the KeyStore and its protection parameters.

• Static factory methods enable creating KeyStore.Builder instances from various sources like type, provider, file, and existing KeyStore objects.

• getKeyStore() returns the KeyStore instance, while getProtectionParameter() retrieves protection details for specific entries.

• The builder ensures that getKeyStore() execution happens within the caller's AccessControlContext for security.

public static abstract class KeyStore.Builder extends Object

A description of a to-be-instantiated KeyStore object.

An instance of this class encapsulates the information needed to instantiate and initialize a KeyStore object. That process is triggered when the {@linkplain #getKeyStore} method is called.

This makes it possible to decouple configuration from KeyStore object creation and e.g. delay a password prompt until it is needed.

See Also

• KeyStore
• KeyStoreBuilderParameters

Protected Constructor Summary

Builder() Construct a new Builder.

Public Method Summary

abstract KeyStore	getKeyStore() Returns the KeyStore described by this object.
abstract KeyStore.ProtectionParameter	getProtectionParameter(String alias) Returns the ProtectionParameters that should be used to obtain the Entry with the given alias.
static KeyStore.Builder	newInstance(String type, Provider provider, KeyStore.ProtectionParameter protection) Returns a new Builder object.
static KeyStore.Builder	newInstance(String type, Provider provider, File file, KeyStore.ProtectionParameter protection) Returns a new Builder object.
static KeyStore.Builder	newInstance(KeyStore keyStore, KeyStore.ProtectionParameter protectionParameter) Returns a new Builder that encapsulates the given KeyStore.

Inherited Method Summary

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Protected Constructors

protected Builder ()

Construct a new Builder.

Public Methods

public abstract KeyStore getKeyStore ()

Returns the KeyStore described by this object.

Returns

• the KeyStore described by this object

Throws

KeyStoreException	if an error occurred during the operation, for example if the KeyStore could not be instantiated or loaded

public abstract KeyStore.ProtectionParameter getProtectionParameter (String alias)

Returns the ProtectionParameters that should be used to obtain the Entry with the given alias. The getKeyStore method must be invoked before this method may be called.

Parameters

alias	the alias of the KeyStore entry

Returns

• the ProtectionParameters that should be used to obtain the Entry with the given alias.

Throws

NullPointerException	if alias is null
KeyStoreException	if an error occurred during the operation
IllegalStateException	if the getKeyStore method has not been invoked prior to calling this method

public static KeyStore.Builder newInstance (String type, Provider provider, KeyStore.ProtectionParameter protection)

Returns a new Builder object.

Each call to the getKeyStore() method on the returned builder will return a new KeyStore object of type type. Its load() method is invoked using a LoadStoreParameter that encapsulates protection.

The KeyStore is instantiated from provider if non-null. Otherwise, all installed providers are searched.

Calls to getProtectionParameter() will return protection.

Note that the getKeyStore() method is executed within the AccessControlContext of the code invoking this method.

Parameters

type	the type of KeyStore to be constructed
provider	the provider from which the KeyStore is to be instantiated (or null)
protection	the ProtectionParameter securing the Keystore

Returns

• a new Builder object

Throws

NullPointerException	if type or protection is null

public static KeyStore.Builder newInstance (String type, Provider provider, File file, KeyStore.ProtectionParameter protection)

Returns a new Builder object.

The first call to the getKeyStore() method on the returned builder will create a KeyStore of type type and call its load() method. The inputStream argument is constructed from file. If protection is a PasswordProtection, the password is obtained by calling the getPassword method. Otherwise, if protection is a CallbackHandlerProtection, the password is obtained by invoking the CallbackHandler.

Subsequent calls to getKeyStore() return the same object as the initial call. If the initial call to failed with a KeyStoreException, subsequent calls also throw a KeyStoreException.

The KeyStore is instantiated from provider if non-null. Otherwise, all installed providers are searched.

Calls to getProtectionParameter() will return a PasswordProtection object encapsulating the password that was used to invoke the load method.

Note that the getKeyStore() method is executed within the AccessControlContext of the code invoking this method.

Parameters

type	the type of KeyStore to be constructed
provider	the provider from which the KeyStore is to be instantiated (or null)
file	the File that contains the KeyStore data
protection	the ProtectionParameter securing the KeyStore data

Returns

• a new Builder object

Throws

NullPointerException	if type, file or protection is null
IllegalArgumentException	if protection is not an instance of either PasswordProtection or CallbackHandlerProtection; or if file does not exist or does not refer to a normal file

public static KeyStore.Builder newInstance (KeyStore keyStore, KeyStore.ProtectionParameter protectionParameter)

Returns a new Builder that encapsulates the given KeyStore. The {@linkplain #getKeyStore} method of the returned object will return keyStore, the {@linkplain #getProtectionParameter getProtectionParameter()} method will return protectionParameters.

This is useful if an existing KeyStore object needs to be used with Builder-based APIs.

Parameters

keyStore	the KeyStore to be encapsulated
protectionParameter	the ProtectionParameter used to protect the KeyStore entries

Returns

• a new Builder object

Throws

NullPointerException	if keyStore or protectionParameters is null
IllegalArgumentException	if the keyStore has not been initialized