Subject.java
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* to you under the Apache License, Version 2.0 (the
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*
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package org.apache.shiro.subject;
import org.apache.shiro.SecurityUtils;
import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationToken;
import org.apache.shiro.authz.AuthorizationException;
import org.apache.shiro.authz.Permission;
import org.apache.shiro.mgt.SecurityManager;
import org.apache.shiro.mgt.SubjectFactory;
import org.apache.shiro.session.Session;
import org.apache.shiro.subject.support.DefaultSubjectContext;
import org.apache.shiro.util.CollectionUtils;
import org.apache.shiro.util.StringUtils;
import java.io.Serializable;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.Callable;
/**
* A {@code Subject} represents state and security operations for a <em>single</em> application user.
* These operations include authentication (login/logout), authorization (access control), and
* session access. It is Shiro's primary mechanism for single-user security functionality.
* <h3>Acquiring a Subject</h3>
* To acquire the currently-executing {@code Subject}, application developers will almost always use
* {@code SecurityUtils}:
* <pre>
* {@link SecurityUtils SecurityUtils}.{@link org.apache.shiro.SecurityUtils#getSubject() getSubject()}</pre>
* Almost all security operations should be performed with the {@code Subject} returned from this method.
* <h3>Permission methods</h3>
* Note that there are many *Permission methods in this interface overloaded to accept String arguments instead of
* {@link Permission Permission} instances. They are a convenience allowing the caller to use a String representation of
* a {@link Permission Permission} if desired. The underlying Authorization subsystem implementations will usually
* simply convert these String values to {@link Permission Permission} instances and then just call the corresponding
* type-safe method. (Shiro's default implementations do String-to-Permission conversion for these methods using
* {@link org.apache.shiro.authz.permission.PermissionResolver PermissionResolver}s.)
* <p/>
* These overloaded *Permission methods forgo type-saftey for the benefit of convenience and simplicity,
* so you should choose which ones to use based on your preferences and needs.
*
* @since 0.1
*/
public interface Subject {
/**
* Returns this Subject's application-wide uniquely identifying principal, or {@code null} if this
* Subject is anonymous because it doesn't yet have any associated account data (for example,
* if they haven't logged in).
* <p/>
* The term <em>principal</em> is just a fancy security term for any identifying attribute(s) of an application
* user, such as a username, or user id, or public key, or anything else you might use in your application to
* identify a user.
* <h4>Uniqueness</h4>
* Although given names and family names (first/last) are technically considered principals as well,
* Shiro expects the object returned from this method to be an identifying attribute unique across
* your entire application.
* <p/>
* This implies that things like given names and family names are usually poor
* candidates as return values since they are rarely guaranteed to be unique; Things often used for this value:
* <ul>
* <li>A {@code long} RDBMS surrogate primary key</li>
* <li>An application-unique username</li>
* <li>A {@link java.util.UUID UUID}</li>
* <li>An LDAP Unique ID</li>
* </ul>
* or any other similar suitable unique mechanism valuable to your application.
* <p/>
* Most implementations will simply return
* <code>{@link #getPrincipals()}.{@link org.apache.shiro.subject.PrincipalCollection#getPrimaryPrincipal() getPrimaryPrincipal()}</code>
*
* @return this Subject's application-specific unique identity.
* @see org.apache.shiro.subject.PrincipalCollection#getPrimaryPrincipal()
*/
Object getPrincipal();
/**
* Returns this Subject's principals (identifying attributes) in the form of a {@code PrincipalCollection} or
* {@code null} if this Subject is anonymous because it doesn't yet have any associated account data (for example,
* if they haven't logged in).
* <p/>
* The word "principals" is nothing more than a fancy security term for identifying attributes associated
* with a Subject, aka, application user. For example, user id, a surname (family/last name), given (first) name,
* social security number, nickname, username, etc, are all examples of a principal.
*
* @return all of this Subject's principals (identifying attributes).
* @see #getPrincipal()
* @see org.apache.shiro.subject.PrincipalCollection#getPrimaryPrincipal()
*/
PrincipalCollection getPrincipals();
/**
* Returns {@code true} if this Subject is permitted to perform an action or access a resource summarized by the
* specified permission string.
* <p/>
* This is an overloaded method for the corresponding type-safe {@link Permission Permission} variant.
* Please see the class-level JavaDoc for more information on these String-based permission methods.
*
* @param permission the String representation of a Permission that is being checked.
* @return true if this Subject is permitted, false otherwise.
* @see #isPermitted(Permission permission)
* @since 0.9
*/
boolean isPermitted(String permission);
/**
* Returns {@code true} if this Subject is permitted to perform an action or access a resource summarized by the
* specified permission.
* <p/>
* More specifically, this method determines if any {@code Permission}s associated
* with the subject {@link Permission#implies(Permission) imply} the specified permission.
*
* @param permission the permission that is being checked.
* @return true if this Subject is permitted, false otherwise.
*/
boolean isPermitted(Permission permission);
/**
* Checks if this Subject implies the given permission strings and returns a boolean array indicating which
* permissions are implied.
* <p/>
* This is an overloaded method for the corresponding type-safe {@link Permission Permission} variant.
* Please see the class-level JavaDoc for more information on these String-based permission methods.
*
* @param permissions the String representations of the Permissions that are being checked.
* @return a boolean array where indices correspond to the index of the
* permissions in the given list. A true value at an index indicates this Subject is permitted for
* for the associated {@code Permission} string in the list. A false value at an index
* indicates otherwise.
* @since 0.9
*/
boolean[] isPermitted(String... permissions);
/**
* Checks if this Subject implies the given Permissions and returns a boolean array indicating which permissions
* are implied.
* <p/>
* More specifically, this method should determine if each {@code Permission} in
* the array is {@link Permission#implies(Permission) implied} by permissions
* already associated with the subject.
* <p/>
* This is primarily a performance-enhancing method to help reduce the number of
* {@link #isPermitted} invocations over the wire in client/server systems.
*
* @param permissions the permissions that are being checked.
* @return a boolean array where indices correspond to the index of the
* permissions in the given list. A true value at an index indicates this Subject is permitted for
* for the associated {@code Permission} object in the list. A false value at an index
* indicates otherwise.
*/
boolean[] isPermitted(List<Permission> permissions);
/**
* Returns {@code true} if this Subject implies all of the specified permission strings, {@code false} otherwise.
* <p/>
* This is an overloaded method for the corresponding type-safe {@link org.apache.shiro.authz.Permission Permission}
* variant. Please see the class-level JavaDoc for more information on these String-based permission methods.
*
* @param permissions the String representations of the Permissions that are being checked.
* @return true if this Subject has all of the specified permissions, false otherwise.
* @see #isPermittedAll(Collection)
* @since 0.9
*/
boolean isPermittedAll(String... permissions);
/**
* Returns {@code true} if this Subject implies all of the specified permissions, {@code false} otherwise.
* <p/>
* More specifically, this method determines if all of the given {@code Permission}s are
* {@link Permission#implies(Permission) implied by} permissions already associated with this Subject.
*
* @param permissions the permissions to check.
* @return true if this Subject has all of the specified permissions, false otherwise.
*/
boolean isPermittedAll(Collection<Permission> permissions);
/**
* Ensures this Subject implies the specified permission String.
* <p/>
* If this subject's existing associated permissions do not {@link Permission#implies(Permission)} imply}
* the given permission, an {@link org.apache.shiro.authz.AuthorizationException} will be thrown.
* <p/>
* This is an overloaded method for the corresponding type-safe {@link Permission Permission} variant.
* Please see the class-level JavaDoc for more information on these String-based permission methods.
*
* @param permission the String representation of the Permission to check.
* @throws org.apache.shiro.authz.AuthorizationException
* if the user does not have the permission.
* @since 0.9
*/
void checkPermission(String permission) throws AuthorizationException;
/**
* Ensures this Subject {@link Permission#implies(Permission) implies} the specified {@code Permission}.
* <p/>
* If this subject's existing associated permissions do not {@link Permission#implies(Permission) imply}
* the given permission, an {@link org.apache.shiro.authz.AuthorizationException} will be thrown.
*
* @param permission the Permission to check.
* @throws org.apache.shiro.authz.AuthorizationException
* if this Subject does not have the permission.
*/
void checkPermission(Permission permission) throws AuthorizationException;
/**
* Ensures this Subject
* {@link org.apache.shiro.authz.Permission#implies(org.apache.shiro.authz.Permission) implies} all of the
* specified permission strings.
* <p/>
* If this subject's existing associated permissions do not
* {@link org.apache.shiro.authz.Permission#implies(org.apache.shiro.authz.Permission) imply} all of the given permissions,
* an {@link org.apache.shiro.authz.AuthorizationException} will be thrown.
* <p/>
* This is an overloaded method for the corresponding type-safe {@link Permission Permission} variant.
* Please see the class-level JavaDoc for more information on these String-based permission methods.
*
* @param permissions the string representations of Permissions to check.
* @throws AuthorizationException if this Subject does not have all of the given permissions.
* @since 0.9
*/
void checkPermissions(String... permissions) throws AuthorizationException;
/**
* Ensures this Subject
* {@link org.apache.shiro.authz.Permission#implies(org.apache.shiro.authz.Permission) implies} all of the
* specified permission strings.
* <p/>
* If this subject's existing associated permissions do not
* {@link org.apache.shiro.authz.Permission#implies(org.apache.shiro.authz.Permission) imply} all of the given permissions,
* an {@link org.apache.shiro.authz.AuthorizationException} will be thrown.
*
* @param permissions the Permissions to check.
* @throws AuthorizationException if this Subject does not have all of the given permissions.
*/
void checkPermissions(Collection<Permission> permissions) throws AuthorizationException;
/**
* Returns {@code true} if this Subject has the specified role, {@code false} otherwise.
*
* @param roleIdentifier the application-specific role identifier (usually a role id or role name).
* @return {@code true} if this Subject has the specified role, {@code false} otherwise.
*/
boolean hasRole(String roleIdentifier);
/**
* Checks if this Subject has the specified roles, returning a boolean array indicating
* which roles are associated.
* <p/>
* This is primarily a performance-enhancing method to help reduce the number of
* {@link #hasRole} invocations over the wire in client/server systems.
*
* @param roleIdentifiers the application-specific role identifiers to check (usually role ids or role names).
* @return a boolean array where indices correspond to the index of the
* roles in the given identifiers. A true value indicates this Subject has the
* role at that index. False indicates this Subject does not have the role at that index.
*/
boolean[] hasRoles(List<String> roleIdentifiers);
/**
* Returns {@code true} if this Subject has all of the specified roles, {@code false} otherwise.
*
* @param roleIdentifiers the application-specific role identifiers to check (usually role ids or role names).
* @return true if this Subject has all the roles, false otherwise.
*/
boolean hasAllRoles(Collection<String> roleIdentifiers);
/**
* Asserts this Subject has the specified role by returning quietly if they do or throwing an
* {@link org.apache.shiro.authz.AuthorizationException} if they do not.
*
* @param roleIdentifier the application-specific role identifier (usually a role id or role name ).
* @throws org.apache.shiro.authz.AuthorizationException
* if this Subject does not have the role.
*/
void checkRole(String roleIdentifier) throws AuthorizationException;
/**
* Asserts this Subject has all of the specified roles by returning quietly if they do or throwing an
* {@link org.apache.shiro.authz.AuthorizationException} if they do not.
*
* @param roleIdentifiers the application-specific role identifiers to check (usually role ids or role names).
* @throws org.apache.shiro.authz.AuthorizationException
* if this Subject does not have all of the specified roles.
*/
void checkRoles(Collection<String> roleIdentifiers) throws AuthorizationException;
/**
* Same as {@link #checkRoles(Collection<String> roleIdentifiers) checkRoles(Collection<String> roleIdentifiers)} but
* doesn't require a collection as a an argument.
* Asserts this Subject has all of the specified roles by returning quietly if they do or throwing an
* {@link org.apache.shiro.authz.AuthorizationException} if they do not.
*
* @param roleIdentifiers roleIdentifiers the application-specific role identifiers to check (usually role ids or role names).
* @throws AuthorizationException org.apache.shiro.authz.AuthorizationException
* if this Subject does not have all of the specified roles.
* @since 1.1.0
*/
void checkRoles(String... roleIdentifiers) throws AuthorizationException;
/**
* Performs a login attempt for this Subject/user. If unsuccessful,
* an {@link AuthenticationException} is thrown, the subclass of which identifies why the attempt failed.
* If successful, the account data associated with the submitted principals/credentials will be
* associated with this {@code Subject} and the method will return quietly.
* <p/>
* Upon returning quietly, this {@code Subject} instance can be considered
* authenticated and {@link #getPrincipal() getPrincipal()} will be non-null and
* {@link #isAuthenticated() isAuthenticated()} will be {@code true}.
*
* @param token the token encapsulating the subject's principals and credentials to be passed to the
* Authentication subsystem for verification.
* @throws org.apache.shiro.authc.AuthenticationException
* if the authentication attempt fails.
* @since 0.9
*/
void login(AuthenticationToken token) throws AuthenticationException;
/**
* Returns {@code true} if this Subject/user proved their identity <em>during their current session</em>
* by providing valid credentials matching those known to the system, {@code false} otherwise.
* <p/>
* Note that even if this Subject's identity has been remembered via 'remember me' services, this method will
* still return {@code false} unless the user has actually logged in with proper credentials <em>during their
* current session</em>. See the {@link #isRemembered() isRemembered()} method JavaDoc for more.
*
* @return {@code true} if this Subject proved their identity during their current session
* by providing valid credentials matching those known to the system, {@code false} otherwise.
* @since 0.9
*/
boolean isAuthenticated();
/**
* Returns {@code true} if this {@code Subject} has an identity (it is not anonymous) and the identity
* (aka {@link #getPrincipals() principals}) is remembered from a successful authentication during a previous
* session.
* <p/>
* Although the underlying implementation determines exactly how this method functions, most implementations have
* this method act as the logical equivalent to this code:
* <pre>
* {@link #getPrincipal() getPrincipal()} != null && !{@link #isAuthenticated() isAuthenticated()}</pre>
* <p/>
* Note as indicated by the above code example, if a {@code Subject} is remembered, they are
* <em>NOT</em> considered authenticated. A check against {@link #isAuthenticated() isAuthenticated()} is a more
* strict check than that reflected by this method. For example, a check to see if a subject can access financial
* information should almost always depend on {@link #isAuthenticated() isAuthenticated()} to <em>guarantee</em> a
* verified identity, and not this method.
* <p/>
* Once the subject is authenticated, they are no longer considered only remembered because their identity would
* have been verified during the current session.
* <h4>Remembered vs Authenticated</h4>
* Authentication is the process of <em>proving</em> you are who you say you are. When a user is only remembered,
* the remembered identity gives the system an idea who that user probably is, but in reality, has no way of
* absolutely <em>guaranteeing</em> if the remembered {@code Subject} represents the user currently
* using the application.
* <p/>
* So although many parts of the application can still perform user-specific logic based on the remembered
* {@link #getPrincipals() principals}, such as customized views, it should never perform highly-sensitive
* operations until the user has legitimately verified their identity by executing a successful authentication
* attempt.
* <p/>
* We see this paradigm all over the web, and we will use <a href="http://www.amazon.com">Amazon.com</a> as an
* example:
* <p/>
* When you visit Amazon.com and perform a login and ask it to 'remember me', it will set a cookie with your
* identity. If you don't log out and your session expires, and you come back, say the next day, Amazon still knows
* who you <em>probably</em> are: you still see all of your book and movie recommendations and similar user-specific
* features since these are based on your (remembered) user id.
* <p/>
* BUT, if you try to do something sensitive, such as access your account's billing data, Amazon forces you
* to do an actual log-in, requiring your username and password.
* <p/>
* This is because although amazon.com assumed your identity from 'remember me', it recognized that you were not
* actually authenticated. The only way to really guarantee you are who you say you are, and therefore allow you
* access to sensitive account data, is to force you to perform an actual successful authentication. You can
* check this guarantee via the {@link #isAuthenticated() isAuthenticated()} method and not via this method.
*
* @return {@code true} if this {@code Subject}'s identity (aka {@link #getPrincipals() principals}) is
* remembered from a successful authentication during a previous session, {@code false} otherwise.
* @since 1.0
*/
boolean isRemembered();
/**
* Returns the application {@code Session} associated with this Subject. If no session exists when this
* method is called, a new session will be created, associated with this Subject, and then returned.
*
* @return the application {@code Session} associated with this Subject.
* @see #getSession(boolean)
* @since 0.2
*/
Session getSession();
/**
* Returns the application {@code Session} associated with this Subject. Based on the boolean argument,
* this method functions as follows:
* <ul>
* <li>If there is already an existing session associated with this {@code Subject}, it is returned and
* the {@code create} argument is ignored.</li>
* <li>If no session exists and {@code create} is {@code true}, a new session will be created, associated with
* this {@code Subject} and then returned.</li>
* <li>If no session exists and {@code create} is {@code false}, {@code null} is returned.</li>
* </ul>
*
* @param create boolean argument determining if a new session should be created or not if there is no existing session.
* @return the application {@code Session} associated with this {@code Subject} or {@code null} based
* on the above described logic.
* @since 0.2
*/
Session getSession(boolean create);
/**
* Logs out this Subject and invalidates and/or removes any associated entities,
* such as a {@link Session Session} and authorization data. After this method is called, the Subject is
* considered 'anonymous' and may continue to be used for another log-in if desired.
* <h3>Web Environment Warning</h3>
* Calling this method in web environments will usually remove any associated session cookie as part of
* session invalidation. Because cookies are part of the HTTP header, and headers can only be set before the
* response body (html, image, etc) is sent, this method in web environments must be called before <em>any</em>
* content has been rendered.
* <p/>
* The typical approach most applications use in this scenario is to redirect the user to a different
* location (e.g. home page) immediately after calling this method. This is an effect of the HTTP protocol
* itself and not a reflection of Shiro's implementation.
* <p/>
* Non-HTTP environments may of course use a logged-out subject for login again if desired.
*/
void logout();
/**
* Associates the specified {@code Callable} with this {@code Subject} instance and then executes it on the
* currently running thread. If you want to execute the {@code Callable} on a different thread, it is better to
* use the {@link #associateWith(Callable)} method instead.
*
* @param callable the Callable to associate with this subject and then execute.
* @param <V> the type of return value the {@code Callable} will return
* @return the resulting object returned by the {@code Callable}'s execution.
* @throws ExecutionException if the {@code Callable}'s {@link Callable#call call} method throws an exception.
* @since 1.0
*/
<V> V execute(Callable<V> callable) throws ExecutionException;
/**
* Associates the specified {@code Runnable} with this {@code Subject} instance and then executes it on the
* currently running thread. If you want to execute the {@code Runnable} on a different thread, it is better to
* use the {@link #associateWith(Runnable)} method instead.
* <p/>
* <b>Note</b>: This method is primarily provided to execute existing/legacy Runnable implementations. It is better
* for new code to use {@link #execute(Callable)} since that supports the ability to return values and catch
* exceptions.
*
* @param runnable the {@code Runnable} to associate with this {@code Subject} and then execute.
* @since 1.0
*/
void execute(Runnable runnable);
/**
* Returns a {@code Callable} instance matching the given argument while additionally ensuring that it will
* retain and execute under this Subject's identity. The returned object can be used with an
* {@link java.util.concurrent.ExecutorService ExecutorService} to execute as this Subject.
* <p/>
* This will effectively ensure that any calls to
* {@code SecurityUtils}.{@link SecurityUtils#getSubject() getSubject()} and related functionality will continue
* to function properly on any thread that executes the returned {@code Callable} instance.
*
* @param callable the callable to execute as this {@code Subject}
* @param <V> the {@code Callable}s return value type
* @return a {@code Callable} that can be run as this {@code Subject}.
* @since 1.0
*/
<V> Callable<V> associateWith(Callable<V> callable);
/**
* Returns a {@code Runnable} instance matching the given argument while additionally ensuring that it will
* retain and execute under this Subject's identity. The returned object can be used with an
* {@link java.util.concurrent.Executor Executor} or another thread to execute as this Subject.
* <p/>
* This will effectively ensure that any calls to
* {@code SecurityUtils}.{@link SecurityUtils#getSubject() getSubject()} and related functionality will continue
* to function properly on any thread that executes the returned {@code Runnable} instance.
* <p/>
* *Note that if you need a return value to be returned as a result of the runnable's execution or if you need to
* react to any Exceptions, it is highly recommended to use the
* {@link #associateWith(java.util.concurrent.Callable) createCallable} method instead of this one.
*
* @param runnable the runnable to execute as this {@code Subject}
* @return a {@code Runnable} that can be run as this {@code Subject} on another thread.
* @see #associateWith (java.util.concurrent.Callable)
* @since 1.0
*/
Runnable associateWith(Runnable runnable);
/**
* Allows this subject to 'run as' or 'assume' another identity indefinitely. This can only be
* called when the {@code Subject} instance already has an identity (i.e. they are remembered from a previous
* log-in or they have authenticated during their current session).
* <p/>
* Some notes about {@code runAs}:
* <ul>
* <li>You can tell if a {@code Subject} is 'running as' another identity by calling the
* {@link #isRunAs() isRunAs()} method.</li>
* <li>If running as another identity, you can determine what the previous 'pre run as' identity
* was by calling the {@link #getPreviousPrincipals() getPreviousPrincipals()} method.</li>
* <li>When you want a {@code Subject} to stop running as another identity, you can return to its previous
* 'pre run as' identity by calling the {@link #releaseRunAs() releaseRunAs()} method.</li>
* </ul>
*
* @param principals the identity to 'run as', aka the identity to <em>assume</em> indefinitely.
* @throws NullPointerException if the specified principals collection is {@code null} or empty.
* @throws IllegalStateException if this {@code Subject} does not yet have an identity of its own.
* @since 1.0
*/
void runAs(PrincipalCollection principals) throws NullPointerException, IllegalStateException;
/**
* Returns {@code true} if this {@code Subject} is 'running as' another identity other than its original one or
* {@code false} otherwise (normal {@code Subject} state). See the {@link #runAs runAs} method for more
* information.
*
* @return {@code true} if this {@code Subject} is 'running as' another identity other than its original one or
* {@code false} otherwise (normal {@code Subject} state).
* @see #runAs
* @since 1.0
*/
boolean isRunAs();
/**
* Returns the previous 'pre run as' identity of this {@code Subject} before assuming the current
* {@link #runAs runAs} identity, or {@code null} if this {@code Subject} is not operating under an assumed
* identity (normal state). See the {@link #runAs runAs} method for more information.
*
* @return the previous 'pre run as' identity of this {@code Subject} before assuming the current
* {@link #runAs runAs} identity, or {@code null} if this {@code Subject} is not operating under an assumed
* identity (normal state).
* @see #runAs
* @since 1.0
*/
PrincipalCollection getPreviousPrincipals();
/**
* Releases the current 'run as' (assumed) identity and reverts back to the previous 'pre run as'
* identity that existed before {@code #runAs runAs} was called.
* <p/>
* This method returne 'run as' (assumed) identity being released or {@code null} if this {@code Subject} is not
* operating under an assumed identity.
*
* @return the 'run as' (assumed) identity being released or {@code null} if this {@code Subject} is not operating
* under an assumed identity.
* @see #runAs
* @since 1.0
*/
PrincipalCollection releaseRunAs();
/**
* Builder design pattern implementation for creating {@link Subject} instances in a simplified way without
* requiring knowledge of Shiro's construction techniques.
* <p/>
* <b>NOTE</b>: This is provided for framework development support only and should typically never be used by
* application developers. {@code Subject} instances should generally be acquired by using
* <code>SecurityUtils.{@link SecurityUtils#getSubject() getSubject()}</code>
* <h4>Usage</h4>
* The simplest usage of this builder is to construct an anonymous, session-less {@code Subject} instance:
* <pre>
* Subject subject = new Subject.{@link #Builder() Builder}().{@link #buildSubject() buildSubject()};</pre>
* The default, no-arg {@code Subject.Builder()} constructor shown above will use the application's
* currently accessible {@code SecurityManager} via
* <code>SecurityUtils.{@link SecurityUtils#getSecurityManager() getSecurityManager()}</code>. You may also
* specify the exact {@code SecurityManager} instance to be used by the additional
* <code>Subject.{@link #Builder(org.apache.shiro.mgt.SecurityManager) Builder(securityManager)}</code>
* constructor if desired.
* <p/>
* All other methods may be called before the {@link #buildSubject() buildSubject()} method to
* provide context on how to construct the {@code Subject} instance. For example, if you have a session id and
* want to acquire the {@code Subject} that 'owns' that session (assuming the session exists and is not expired):
* <pre>
* Subject subject = new Subject.Builder().sessionId(sessionId).buildSubject();</pre>
* <p/>
* Similarly, if you want a {@code Subject} instance reflecting a certain identity:
* <pre>
* PrincipalCollection principals = new SimplePrincipalCollection("username", <em>yourRealmName</em>);
* Subject subject = new Subject.Builder().principals(principals).build();</pre>
* <p/>
* <b>Note*</b> that the returned {@code Subject} instance is <b>not</b> automatically bound to the application (thread)
* for further use. That is,
* {@link org.apache.shiro.SecurityUtils SecurityUtils}.{@link org.apache.shiro.SecurityUtils#getSubject() getSubject()}
* will not automatically return the same instance as what is returned by the builder. It is up to the framework
* developer to bind the built {@code Subject} for continued use if desired.
*
* @since 1.0
*/
public static class Builder {
/**
* Hold all contextual data via the Builder instance's method invocations to be sent to the
* {@code SecurityManager} during the {@link #buildSubject} call.
*/
private final SubjectContext subjectContext;
/**
* The SecurityManager to invoke during the {@link #buildSubject} call.
*/
private final SecurityManager securityManager;
/**
* Constructs a new {@link Subject.Builder} instance, using the {@code SecurityManager} instance available
* to the calling code as determined by a call to {@link org.apache.shiro.SecurityUtils#getSecurityManager()}
* to build the {@code Subject} instance.
*/
public Builder() {
this(SecurityUtils.getSecurityManager());
}
/**
* Constructs a new {@link Subject.Builder} instance which will use the specified {@code SecurityManager} when
* building the {@code Subject} instance.
*
* @param securityManager the {@code SecurityManager} to use when building the {@code Subject} instance.
*/
public Builder(SecurityManager securityManager) {
if (securityManager == null) {
throw new NullPointerException("SecurityManager method argument cannot be null.");
}
this.securityManager = securityManager;
this.subjectContext = newSubjectContextInstance();
if (this.subjectContext == null) {
throw new IllegalStateException("Subject instance returned from 'newSubjectContextInstance' " +
"cannot be null.");
}
this.subjectContext.setSecurityManager(securityManager);
}
/**
* Creates a new {@code SubjectContext} instance to be used to populate with subject contextual data that
* will then be sent to the {@code SecurityManager} to create a new {@code Subject} instance.
*
* @return a new {@code SubjectContext} instance
*/
protected SubjectContext newSubjectContextInstance() {
return new DefaultSubjectContext();
}
/**
* Returns the backing context used to build the {@code Subject} instance, available to subclasses
* since the {@code context} class attribute is marked as {@code private}.
*
* @return the backing context used to build the {@code Subject} instance, available to subclasses.
*/
protected SubjectContext getSubjectContext() {
return this.subjectContext;
}
/**
* Enables building a {@link Subject Subject} instance that owns the {@link Session Session} with the
* specified {@code sessionId}.
* <p/>
* Usually when specifying a {@code sessionId}, no other {@code Builder} methods would be specified because
* everything else (principals, inet address, etc) can usually be reconstructed based on the referenced
* session alone. In other words, this is almost always sufficient:
* <pre>
* new Subject.Builder().sessionId(sessionId).buildSubject();</pre>
* <p/>
* <b>Although simple in concept, this method provides very powerful functionality previously absent in almost
* all Java environments:</b>
* <p/>
* The ability to reference a {@code Subject} and their server-side session
* <em>across clients of different mediums</em> such as web applications, Java applets,
* standalone C# clients over XML-RPC and/or SOAP, and many others. This is a <em>huge</em>
* benefit in heterogeneous enterprise applications.
* <p/>
* To maintain session integrity across client mediums, the {@code sessionId} <b>must</b> be transmitted
* to all client mediums securely (e.g. over SSL) to prevent man-in-the-middle attacks. This
* is nothing new - all web applications are susceptible to the same problem when transmitting
* {@code Cookie}s or when using URL rewriting. As long as the
* {@code sessionId} is transmitted securely, session integrity can be maintained.
*
* @param sessionId the id of the session that backs the desired Subject being acquired.
* @return this {@code Builder} instance for method chaining.
*/
public Builder sessionId(Serializable sessionId) {
if (sessionId != null) {
this.subjectContext.setSessionId(sessionId);
}
return this;
}
/**
* Ensures the {@code Subject} being built will reflect the specified host name or IP as its originating
* location.
*
* @param host the host name or IP address to use as the {@code Subject}'s originating location.
* @return this {@code Builder} instance for method chaining.
*/
public Builder host(String host) {
if (StringUtils.hasText(host)) {
this.subjectContext.setHost(host);
}
return this;
}
/**
* Ensures the {@code Subject} being built will use the specified {@link Session} instance. Note that it is
* more common to use the {@link #sessionId sessionId} builder method rather than having to construct a
* {@code Session} instance for this method.
*
* @param session the session to use as the {@code Subject}'s {@link Session}
* @return this {@code Builder} instance for method chaining.
*/
public Builder session(Session session) {
if (session != null) {
this.subjectContext.setSession(session);
}
return this;
}
/**
* Ensures the {@code Subject} being built will reflect the specified principals (aka identity).
* <p/>
* For example, if your application's unique identifier for users is a {@code String} username, and you wanted
* to create a {@code Subject} instance that reflected a user whose username is
* '{@code jsmith}', and you knew the Realm that could acquire {@code jsmith}'s principals based on the username
* was named "{@code myRealm}", you might create the '{@code jsmith} {@code Subject} instance this
* way:
* <pre>
* PrincipalCollection identity = new {@link org.apache.shiro.subject.SimplePrincipalCollection#SimplePrincipalCollection(Object, String) SimplePrincipalCollection}("jsmith", "myRealm");
* Subject jsmith = new Subject.Builder().principals(identity).buildSubject();</pre>
* <p/>
* Similarly, if your application's unique identifier for users is a {@code long} value (such as might be used
* as a primary key in a relational database) and you were using a {@code JDBC}
* {@code Realm} named, (unimaginatively) "jdbcRealm", you might create the Subject
* instance this way:
* <pre>
* long userId = //get user ID from somewhere
* PrincipalCollection userIdentity = new {@link org.apache.shiro.subject.SimplePrincipalCollection#SimplePrincipalCollection(Object, String) SimplePrincipalCollection}(<em>userId</em>, "jdbcRealm");
* Subject user = new Subject.Builder().principals(identity).buildSubject();</pre>
*
* @param principals the principals to use as the {@code Subject}'s identity.
* @return this {@code Builder} instance for method chaining.
*/
public Builder principals(PrincipalCollection principals) {
if (!CollectionUtils.isEmpty(principals)) {
this.subjectContext.setPrincipals(principals);
}
return this;
}
/**
* Configures whether or not the created Subject instance can create a new {@code Session} if one does not
* already exist. If set to {@code false}, any application calls to
* {@code subject.getSession()} or {@code subject.getSession(true))} will result in a SessionException.
* <p/>
* This setting is {@code true} by default, as most applications find value in sessions.
*
* @param enabled whether or not the created Subject instance can create a new {@code Session} if one does not
* already exist.
* @return this {@code Builder} instance for method chaining.
* @since 1.2
*/
public Builder sessionCreationEnabled(boolean enabled) {
this.subjectContext.setSessionCreationEnabled(enabled);
return this;
}
/**
* Ensures the {@code Subject} being built will be considered
* {@link org.apache.shiro.subject.Subject#isAuthenticated() authenticated}. Per the
* {@link org.apache.shiro.subject.Subject#isAuthenticated() isAuthenticated()} JavaDoc, be careful
* when specifying {@code true} - you should know what you are doing and have a good reason for ignoring Shiro's
* default authentication state mechanisms.
*
* @param authenticated whether or not the built {@code Subject} will be considered authenticated.
* @return this {@code Builder} instance for method chaining.
* @see org.apache.shiro.subject.Subject#isAuthenticated()
*/
public Builder authenticated(boolean authenticated) {
this.subjectContext.setAuthenticated(authenticated);
return this;
}
/**
* Allows custom attributes to be added to the underlying context {@code Map} used to construct the
* {@link Subject} instance.
* <p/>
* A {@code null} key throws an {@link IllegalArgumentException}. A {@code null} value effectively removes
* any previously stored attribute under the given key from the context map.
* <p/>
* <b>*NOTE*:</b> This method is only useful when configuring Shiro with a custom {@link SubjectFactory}
* implementation. This method allows end-users to append additional data to the context map which the
* {@code SubjectFactory} implementation can use when building custom Subject instances. As such, this method
* is only useful when a custom {@code SubjectFactory} implementation has been configured.
*
* @param attributeKey the key under which the corresponding value will be stored in the context {@code Map}.
* @param attributeValue the value to store in the context map under the specified {@code attributeKey}.
* @return this {@code Builder} instance for method chaining.
* @throws IllegalArgumentException if the {@code attributeKey} is {@code null}.
* @see SubjectFactory#createSubject(SubjectContext)
*/
public Builder contextAttribute(String attributeKey, Object attributeValue) {
if (attributeKey == null) {
String msg = "Subject context map key cannot be null.";
throw new IllegalArgumentException(msg);
}
if (attributeValue == null) {
this.subjectContext.remove(attributeKey);
} else {
this.subjectContext.put(attributeKey, attributeValue);
}
return this;
}
/**
* Creates and returns a new {@code Subject} instance reflecting the cumulative state acquired by the
* other methods in this class.
* <p/>
* This {@code Builder} instance will still retain the underlying state after this method is called - it
* will not clear it; repeated calls to this method will return multiple {@link Subject} instances, all
* reflecting the exact same state. If a new (different) {@code Subject} is to be constructed, a new
* {@code Builder} instance must be created.
* <p/>
* <b>Note</b> that the returned {@code Subject} instance is <b>not</b> automatically bound to the application
* (thread) for further use. That is,
* {@link org.apache.shiro.SecurityUtils SecurityUtils}.{@link org.apache.shiro.SecurityUtils#getSubject() getSubject()}
* will not automatically return the same instance as what is returned by the builder. It is up to the
* framework developer to bind the returned {@code Subject} for continued use if desired.
*
* @return a new {@code Subject} instance reflecting the cumulative state acquired by the
* other methods in this class.
*/
public Subject buildSubject() {
return this.securityManager.createSubject(this.subjectContext);
}
}
}