Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.authentication.SystemPrincipal

This class represents Derby's notion of a principal, a concept of user identity with controlled access to Derby System Privileges. An authenticated user may have other identities which make sense in other code domains.

Note that principal names do NOT follow Authorization Identifier rules. For instance, although edward and edWard both match the normalized authorization identifier EDWARD, the instances SystemPrincipal("edward") and SystemPrincipal("edWard") represent different principals under the methods getName(), equals(), and hashCode().

According to JAASRefGuide, Principal classes must implement Serializable.

Field Summary

Modifier and Type	Field and Description
private final String	name The name of the principal.
pack-priv static final long	serialVersionUID BTW, this class currently does not require special handling during serialization/deserialization, so, there's no need to define methods `readObject(ObjectInputStream)` and `writeObject(ObjectOutputStream)`.

Constructor Summary

Access	Constructor and Description
public	SystemPrincipal(String the name of the principal name) Constructs a principal for a given name.

Method Summary

Modifier and Type	Method and Description
public boolean	Returns: true if the principal passed in is the same as that encapsulated by this principal, and false otherwise equals(Object principal to compare with other) Overrides java.lang.Object.equals. Implements java.security.Principal.equals. Compares this principal to the specified object.
public String	Returns: the name of this principal getName() Implements java.security.Principal.getName. Returns the name of this principal.
public int	Returns: a hashcode for this principal hashCode() Overrides java.lang.Object.hashCode. Implements java.security.Principal.hashCode. Returns a hashcode for this principal.
private void	readObject(ObjectInputStream s) Called upon deserialization for restoring the state of this SystemPrincipal from a stream.
public String	Returns: a string representation of this principal toString() Overrides java.lang.Object.toString. Implements java.security.Principal.toString. Returns a string representation of this principal.
private static void	validateName(String the name of the principal name) Verify that the specified name of the principal is valid.

Inherited from java.lang.Object:: clone finalize getClass notify notifyAll wait wait wait

Field Detail

name back to summary

name	back to summary
private final String name The name of the principal. Note that the name is not a "normalized" Authorization Identifier. This is due to peculiarities of the Java Security Runtime, which compares a `javax.security.auth.Subject`'s Principals against the literal Principal name as declared in the policy files, and not against the return value of method `getName()`. So, a normalization of names within SystemPrincipal doesn't affect permission checking by the SecurityManager. In order for a `javax.security.auth.Subject` to be granted permissions on the basis Authorization Identifier rules, e.g., for a Subject authenticated as edWard to fall under a policy clause declared for EDWARD, the Subject has to be constructed (or augmented) with both the literal name and the normalized Authorization Identifier. As an alternative approach, class `SystemPrincipal` could implement the non-standard interface `com.sun.security.auth.PrincipalComparator`, which declares a method `implies(Subject)` that would allow for Principals to match Subjects on the basis of normalized Authorization Identifiers. But then we'd be relying upon non-standard Security Runtime behaviour. See Also User Names & Authorization Identifiers in Derby

private final String name

The name of the principal.

Note that the name is not a "normalized" Authorization Identifier. This is due to peculiarities of the Java Security Runtime, which compares a javax.security.auth.Subject's Principals against the literal Principal name as declared in the policy files, and not against the return value of method getName(). So, a normalization of names within SystemPrincipal doesn't affect permission checking by the SecurityManager.

In order for a javax.security.auth.Subject to be granted permissions on the basis Authorization Identifier rules, e.g., for a Subject authenticated as edWard to fall under a policy clause declared for EDWARD, the Subject has to be constructed (or augmented) with both the literal name and the normalized Authorization Identifier.

As an alternative approach, class SystemPrincipal could implement the non-standard interface com.sun.security.auth.PrincipalComparator, which declares a method implies(Subject) that would allow for Principals to match Subjects on the basis of normalized Authorization Identifiers. But then we'd be relying upon non-standard Security Runtime behaviour.

See Also: User Names & Authorization Identifiers in Derby

serialVersionUID	back to summary
pack-priv static final long serialVersionUID BTW, this class currently does not require special handling during serialization/deserialization, so, there's no need to define methods `readObject(ObjectInputStream)` and `writeObject(ObjectOutputStream)`.

Constructor Detail

SystemPrincipal	back to summary
public SystemPrincipal(String name) Constructs a principal for a given name. Parameters name:String the name of the principal Exceptions NullPointerException: if name is null IllegalArgumentException: if name is not a legal Principal name

SystemPrincipal

back to summary

public SystemPrincipal(String name)

Constructs a principal for a given name.

Parameters

name:String: the name of the principal

Exceptions

NullPointerException:: if name is null
IllegalArgumentException:: if name is not a legal Principal name

Method Detail

equals back to summary

equals	back to summary
public boolean equals(Object other) Overrides java.lang.Object.equals. Implements java.security.Principal.equals. Compares this principal to the specified object. Returns true if the object passed in matches the principal represented by the implementation of this interface. Parameters other:Object principal to compare with Returns:boolean true if the principal passed in is the same as that encapsulated by this principal, and false otherwise See Also `Principal#equals`

public boolean equals(Object other)

Overrides java.lang.Object.equals.

Implements java.security.Principal.equals.

Compares this principal to the specified object. Returns true if the object passed in matches the principal represented by the implementation of this interface.

Parameters

other:Object: principal to compare with

Returns:boolean

true if the principal passed in is the same as that encapsulated by this principal, and false otherwise

See Also

Principal#equals

getName back to summary

getName	back to summary
public String getName() Implements java.security.Principal.getName. Returns the name of this principal. Returns:String the name of this principal See Also `Principal#getName()`

public String getName()

Implements java.security.Principal.getName.

Returns the name of this principal.

Returns:String: the name of this principal
See Also: Principal#getName()

hashCode back to summary

hashCode	back to summary
public int hashCode() Overrides java.lang.Object.hashCode. Implements java.security.Principal.hashCode. Returns a hashcode for this principal. Returns:int a hashcode for this principal See Also `Principal#hashCode()`

public int hashCode()

Overrides java.lang.Object.hashCode.

Implements java.security.Principal.hashCode.

Returns a hashcode for this principal.

Returns:int: a hashcode for this principal
See Also: Principal#hashCode()

readObject	back to summary
private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException Called upon deserialization for restoring the state of this SystemPrincipal from a stream.

toString back to summary

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Implements java.security.Principal.toString. Returns a string representation of this principal. Returns:String a string representation of this principal See Also `Principal#toString()`

public String toString()

Overrides java.lang.Object.toString.

Implements java.security.Principal.toString.

Returns a string representation of this principal.

Returns:String: a string representation of this principal
See Also: Principal#toString()

validateName	back to summary
private static void validateName(String name) Verify that the specified name of the principal is valid. Parameters name:String the name of the principal Exceptions NullPointerException: if name is null IllegalArgumentException: if name is not a legal Principal name

validateName

back to summary

private static void validateName(String name)

Verify that the specified name of the principal is valid.

Parameters

name:String: the name of the principal

Exceptions

NullPointerException:: if name is null
IllegalArgumentException:: if name is not a legal Principal name

public final Class SystemPrincipal

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail